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9098887 | Remodeling domain interfaces to enhance heterodimer formation. | An anti-p185HER2/anti-CD3 humanized bispecific diabody was previously constructed from two cross-over single-chain Fv in which YH and VL domains of the parent antibodies are present on different polypeptides. Here this diabody is used to evaluate domain interface engineering strategies for enhancing the formation of fu... |
9098885 | Structural comparison of cupredoxin domains: domain recycling to construct proteins with novel functions. | The three-dimensional structures of the copper-containing enzymes ascorbate oxidase, ceruloplasmin, and nitrite reductase, comprised of multiple domains with a cupredoxin fold, are consistent with having evolved from a common ancestor. The presence or absence of copper sites has complicated ascertaining the structural ... |
9098073 | The Bacteroides mobilizable transposon Tn4555 integrates by a site-specific recombination mechanism similar to that of the gram-positive bacterial element Tn916. | The Bacteroides mobilizable transposon Tn4555 is a 12.2-kb molecule that encodes resistance to cefoxitin. Conjugal transposition is hypothesized to occur via a circular intermediate and is stimulated by coresident tetracycline resistance elements and low levels of tetracycline. In this work, the ends of the transposon ... |
9098047 | Characterization and subcellular localization of the Clostridium thermocellum scaffoldin dockerin binding protein SdbA. | This article reports the characterization of the Clostridium thermocellum SdbA protein thought to anchor the cellulosome to the bacterial cell surface. The NH2-terminal region of SdbA consists of a cohesin domain which specifically binds the dockerin domain of the cellulosomal scaffolding protein CipA. The COOH-termina... |
9096306 | A direct comparison of helix propensity in proteins and peptides. | alpha-Helical secondary structure occurs widely in globular proteins and its formation is a key step in their folding. As a consequence, understanding the energetics of helix formation is crucial to understanding protein folding and stability. We have measured the helix propensities of the nonpolar amino acids for an a... |
9096303 | Supercoiling-dependent flexibility of adenosine-tract-containing DNA detected by a topological method. | Intrinsically bent DNA sequences have been implicated in the activation of transcription by promoting juxtaposition of DNA sequences near the terminal loop of a superhelical domain. We have developed a novel topological assay for DNA looping based on lambda integrative recombination to study the effects of intrinsicall... |
9092675 | Direct genetic selection of two classes of R17/MS2 coat proteins with altered capsid assembly properties and expanded RNA-binding activities. | RNA challenge phages are derivatives of bacteriophage P22 that enable direct genetic selection for a specific RNA-protein interaction. The bacteriophage P22 R17 encodes a wild-type R17 operator site and undergoes lysogenic development following infection of susceptible bacterial strains that express the R17/MS2 coat pr... |
9120024 | A nucleotide substitution in the promoter of human angiotensinogen is associated with essential hypertension and affects basal transcription in vitro. | In earlier studies, we provided statistical evidence that individual differences in the angiotensinogen gene, the precursor of the vasoactive hormone angiotensin II, constitute inherited predispositions to essential hypertension in humans. We have now identified a common variant in the proximal promoter, the presence o... |
9090793 | Advances in microbial steroid biotransformation. | Microbial biotransformations of various steroids are reviewed. Developmental studies on hydroxylation, carbon-carbon bond cleavage, enzymatic catalysis in nonaqueous solvents, use of cyclodextrin medium, cell immobilization, and new microbial reactions are highlighted. Various steroid substrates, their metabolites and ... |
9087523 | Dimorphic distribution of the two main GABA(A) binding sites in cortical and limbic areas of a rodent living in natural environmental conditions. | Labeling of the two more important gamma-aminobutyric acidA (GABA(A)) supramolecular sites with [3H] muscimol (GABA(A)) and [3H] flunitrazepam (benzodiazepine) provided saturable, stable, and dimorphic binding activities in cortical and limbic regions of the wood mouse Apodemus sylvaticus. Of the cortical layers, which... |
9087487 | Improved activity of a synthetic indolicidin analog. | A novel cationic peptide, CP-11, based on the structure of the bovine neutrophil peptide indolicidin, was designed to increase the number of positively charged residues, maintain the short length (13 amino acids), and enhance the amphipathicity relative to those of indolicidin. CP-11, and especially its carboxymethylat... |
9083688 | Two-dimensional arrangement of a functional protein by cysteine-gold interaction: enzyme activity and characterization of a protein monolayer on a gold substrate. | We have characterized the functional protein, myosin subfragment 1 (S1), attached to a gold substrate by the sulfhydryl groups of cysteine in proteins. The amino groups of the regulatory light chain (RLC) isolated from myosin were labeled with a radioisotope (125I), and the labeled RLC was incorporated into S1 from whi... |
9083687 | Spectroscopy and structure of bacteriochlorophyll dimers. I. Structural consequences of nonconservative circular dichroism spectra. | The origin of the nonconservative nature of the circular dichroism (CD) spectrum of bacteriochlorophyll dimers is investigated. It is shown that coupling between the Qy and Qx transitions can, under rather restricting circumstances, lead to an asymmetrical CD spectrum: only for a limited set of relative orientations of... |
9083680 | Sizing membrane pores in lipid vesicles by leakage of co-encapsulated markers: pore formation by melittin. | Many toxins and antimicrobial peptides permeabilize membrane vesicles by forming multimeric pores. Determination of the size of such pores is an important first step for understanding their structure and the mechanism of their self-assembly. We report a simple method for sizing pores in vesicles based on the differenti... |
9083672 | Solubilization and reconstitution of vesicular stomatitis virus envelope using octylglucoside. | Reconstituted vesicular stomatitis virus envelopes or virosomes are formed by detergent removal from solubilized intact virus. We have monitored the solubilization process of the intact vesicular stomatitis virus by the nonionic surfactant octylglucoside at various initial virus concentrations by employing turbidity me... |
9083669 | Differences in the physical properties of lipid monolayers and bilayers on a spherical solid support. | A monolayer of 1,2-dipalmitoyl-d62-glycero-3-phosphocholine (DPPC-d62) coated onto silanized silica beads (spherical supported monolayer: SSM) is studied by 2H-NMR and DSC. The results are compared with those obtained from a single bilayer on the same solid support (spherical supported vesicles: SSV) and from multilame... |
9173901 | N-terminal type I modules required for fibronectin binding to fibroblasts and to fibronectin's III1 module. | Assembly of fibronectin fibrils occurs at the surface of substrate-attached cells and is mediated by the first to the fifth type I modules in the N-terminal 70 kDa portion of the molecule. The first type III module (III1) of fibronectin, not present in the 70 kDa portion, contains a conformation-dependent binding site ... |
9079903 | Mutations affecting substrate specificity of the Bacillus subtilis multidrug transporter Bmr. | The Bacillus subtilis multidrug transporter Bmr, a member of the major facilitator superfamily of transporters, causes the efflux of a number of structurally unrelated toxic compounds from cells. We have shown previously that the activity of Bmr can be inhibited by the plant alkaloid reserpine. Here we demonstrate that... |
9119463 | Protection against murine listeriosis by an attenuated recombinant Salmonella typhimurium vaccine strain that secretes the naturally somatic antigen superoxide dismutase. | A recombinant (r)-Salmonella typhimurium aroA vaccine strain was constructed which secretes the naturally somatic protein of Listeria monocytogenes, superoxide dismutase (SOD), by the HlyB/HlyD/TolC export machinery. Vaccine efficacy of the SOD-bearing carrier strain was compared with that of the p60-secreting construc... |
9119453 | Binding of the 68-kilodalton protein of Mycobacterium avium to alpha(v)beta3 on human monocyte-derived macrophages enhances complement receptor type 3 expression. | Attachment to and uptake by host cells are important early events in the pathogenesis of intracellular organisms such as Mycobacterium avium. Monocyte-derived macrophages (MDM) are known to express multiple surface receptors that play a role in binding to and uptake of M. avium. These include complement receptor type 3... |
9121436 | DNA-binding specificity of Mcm1: operator mutations that alter DNA-bending and transcriptional activities by a MADS box protein. | The yeast Mcm1 protein is a member of the MADS box family of transcriptional regulatory factors, a class of DNA-binding proteins found in such diverse organisms as yeast, plants, flies, and humans. To explore the protein-DNA interactions of Mcm1 in vivo and in vitro, we have introduced an extensive series of base pair ... |
9060433 | Mispair extension fidelity of human immunodeficiency virus type 1 reverse transcriptases with amino acid substitutions affecting Tyr115. | The role of Tyr115 of human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) in the mispair extension fidelity of DNA dependent DNA synthesis was analysed by using a series of 15 mutant enzymes with substitutions at Tyr115. Their kinetic parameters for elongation using homopolymeric RNA-DNA and heteropoly... |
9060691 | Human immunodeficiency virus strains differ in their ability to infect CD4+ cells expressing the rat homolog of CXCR-4 (fusin). | A clade B strain of human immunodeficiency virus type 1 (HIV-1(LAI)) could infect CD4+ cells expressing human CXCR-4 (fusin) or its rat homolog with similar efficacy. By contrast, cells expressing rat CXCR-4 were not permissive to HIV-1(NDK) (clade D), HIV-2(ROD), or HIV-1(LAI) with chimeric envelope protein gp120 bear... |
9060676 | A role for naturally occurring variation of the murine coronavirus spike protein in stabilizing association with the cellular receptor. | Murine hepatitis virus (MHV), a coronavirus, initiates infection by binding to its cellular receptor (MHVR) via spike (S) proteins projecting from the virion membrane. The structures of these S proteins vary considerably among MHV strains, and this variation is generally considered to be important in determining the st... |
9060658 | Expression of the human papillomavirus type 11 L1 capsid protein in Escherichia coli: characterization of protein domains involved in DNA binding and capsid assembly. | The L1 major capsid protein of human papillomavirus type 11 (HPV-11) was expressed in Escherichia coli, and the soluble recombinant protein was purified to near homogeneity. The recombinant L1 protein bound DNA as determined by the Southwestern assay method, and recombinant mutant L1 proteins localized the DNA-binding ... |
9060635 | Differential regulation of the antibody responses to Gag and Env proteins of human immunodeficiency virus type 1. | We have studied the antibody responses to Env and Gag antigens of human immunodeficiency virus type 1 (HIV-1) in several cohorts of HIV-1-infected individuals: long-term nonprogressors, progressors to disease, acute seroconvertors, and recipients of HIV-1 protease inhibitors. We conclude that the antibody responses to ... |
9060634 | CD44 is not required for poliovirus replication. | The identification of a monoclonal antibody, AF3, which recognizes a single isoform of the cell surface protein CD44 and preferentially blocks binding of serotype 2 poliovirus to HeLa cells, suggested that CD44 might be an accessory molecule to Pvr, the cell receptor for poliovirus, and that it could play a role in the... |
9060615 | Specific repression of Tax trans-activation by TAR RNA-binding protein TRBP. | The human T-cell leukemia virus type 1 (HTLV-1)-encoded Tax protein activates transcription from the long terminal repetition via association with host cellular factors. In this study, we searched for cellular proteins that interact with Tax and modulate its activity by using the yeast two-hybrid system. One of the str... |
9060610 | Dominant-negative mutants of human MxA protein: domains in the carboxy-terminal moiety are important for oligomerization and antiviral activity. | Human MxA protein is an interferon-induced 76-kDa GTPase that exhibits antiviral activity against several RNA viruses. Wild-type MxA accumulates in the cytoplasm of cells. TMxA, a modified form of wild-type MxA carrying a foreign nuclear localization signal, accumulates in the cell nucleus. Here we show that MxA protei... |
11237050 | Ultrasound promoted N-alkylation of pyrrole using potassium superoxide as base in crown ether. | Ultrasound accelerates the N-alkylation of pyrrole by alkylating reagents using potassium superoxide as base in the presence of 18-crown-6. A much lower yield of N-alkylated pyrrole was realized in the absence of ultrasound. N-alkylating reagents employed for pyrrole are methyl iodide, ethyl bromide, benzyl bromide, as... |
11669682 | Comparative Analysis of the Conformations of Symmetrically and Asymmetrically Deca- and Undecasubstituted Porphyrins Bearing Meso-Alkyl or -Aryl Groups. | Conformational analysis of highly substituted porphyrins has potential implications for modeling the behavior of macrocycles in tetrapyrrole-containing protein complexes and during catalytic reactions. In order to study the influence of different substituent patterns on the conformation of the porphyrin macrocycle, a s... |
15739414 | [The determination of enantiomeric purity for 1,1'-binaphthyl-2,2'-diol by high performance liquid chromatography]. | In the past few years, much attention has been focused on the studies of the chirality recognition properties of chiral crown ether hosts containing the binaphthyl unit. The application of chiral 1,1'-binaphthyl-2,2'-diol (1) in asymmetric synthesis has been proved fruitful. Consequently, the preparation of optically a... |
15299953 | Structure of the Fab fragment from a neutralizing monoclonal antibody directed against an epitope of gp41 from HIV-1. | The structure of a Fab fragment of a monoclonal antibody (1583) that neutralizes a broad range of HIV-1 isolates has been solved by X-ray crystallography. This antibody is directed against a poliovirus/HIV-I chimaera which presents a conserved epitope of the envelope protein gp41. Crystals of 1583 were obtained in the ... |
9376128 | Interactions between single-stranded DNA binding protein and oligonucleotide analogs with different backbone chemistries. | Chemical modification of backbone structures has been an important strategy in designing oligonucleotides capable of improved antisense effects. However, altered backbone chemistry may also affect the binding of oligonucleotides to key cellular proteins, and thus may impact on the overall biological action of antisense... |
9376132 | Comparison of the antibody response to bee venom phospholipase A2 induced by natural exposure in humans or by immunization in mice. | Two human and twelve murine monoclonal antibodies directed against the main bee venom allergen phospholipase A2 (PLA) were evaluated for their fine specificity of binding to antigen and their ability to inhibit the enzymatic activity of the antigen. Antibodies were induced by natural exposure of beekeepers to bee venom... |
9376131 | Medium format enhancement: design of an immobilized heparin affinity media for industrial bioprocessing. | Affinity chromatography is one of the most powerful and selective separation methods available. Recently, affinity methods are being incorporated into industrial processes with some frequency. One of the reasons for this is that affinity media robust enough for industrial bioprocessing are now available. By robust is m... |
9376130 | Simulated dipeptide recognition by vancomycin. | The antimicrobial activity of vancomycin and related glycopeptide antibiotics is due to stereospecific recognition of polypeptide components in bacterial cell walls. To better understand how these antibiotics recognize polypeptide determinants, we have developed dynamic models of the complexes formed by the vancomycin ... |
9376129 | Binding of the soluble, truncated form of an Fc receptor (mouse Fc gamma RII) to membrane-bound IgG as measured by total internal reflection fluorescence microscopy. | Total internal reflection fluorescence microscopy has been used to investigate the binding of the soluble extracellular domain of mouse Fc gamma RII (sFc gamma RII) to an anti-trinitrophenyl monoclonal mouse IgG2b (GK14.1) specifically bound to substrate-supported planar membranes composed of dipalmitoylphosphatidylcho... |
9332163 | Lipoproteins: their potential as endogenous target oriented novel drug delivery system. | Targeting of drugs to specific cellular sites is a major area of interest now a day. Various carrier systems, viz, liposomes, resealed erythrocytes, niosomes, immunomodulated nanospheres, etc. have been reported. A newer class of carrier system based on endogenous origin has been identified as lipoproteins. The present... |
9207895 | Carcinogenicity study of beta-cyclodextrin in F344 rats. | The carcinogenicity of beta-cyclodextrin, a cyclic, water-soluble carbohydrate comprising seven glucose units, was examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given the compound in their diet at concentrations of 0 (control), 2.5 or 5% for 104 wk. Surviving rats were then given a basal d... |
9183933 | [What is a virus?]. | Viruses are simple biological particles, consisting of a genome, a protein capsid and, in the case of enveloped viruses, an external lipidic envelope. Owing to the presence of envelope, most enveloped viruses are fragile although some exceptions may be observed. Viruses behave as complete intracellular parasites. Their... |
9177887 | Controlled mechanical hypoventilation in a paediatric burn patient as treatment of acute respiratory distress syndrome. | The paediatric patient we are describing suffered a scald injury covering 83 per cent of the total body surface area (TBSA). This injury was complicated by Klebsiella pneumoniae septicaemia resulting in multiorgan failure (MOF). Acute respiratory distress syndrome (ARDS), gastrointestinal insufficiency, hepathopathy an... |
9172094 | Photochemical stability of the inclusion complexes formed by modified 1,4-dihydropyridine derivatives with beta-cyclodextrin. | The results of studies of photochemical stability of the derivatives of 1,4-dihydropyridine (NR) are reported. The NR with various substituents (-NO2, -Cl, -F, CF3) at different positions in the phenyl ring were identified by UV spectrophotometry. Photodegradation of NR in the inclusion complexes with beta-cyclodextrin... |
9235813 | [Comparative endoscopic study of gastroduodenal tolerance of piroxicam-beta-cyclodextrin vs piroxicam]. | The gastroduodenal tolerability of piroxicam-beta-cyclodextrine was evaluated in a double-blind, parallel group study in 32 healthy male volunteers. The doses used were 20 mg piroxicam-beta-cyclodextrin vs 20 mg piroxicam daily over a period of 14 days. Gastric tolerability was assessed by using upper endoscopy. Gastro... |
9146035 | Use of subambient differential scanning calorimetry to monitor the frozen-state behavior of blends of excipients for freeze-drying. | The purpose of this study was evaluation of mannitol and its blends with other excipients commonly used as freeze-drying cryoprotectants or bulking agents in simulated lyophilization conditions. Subambient differential scanning calorimetry (DSC) has been used as an analytical tool to evaluate the phenomena from both a ... |
9140779 | Enantioselective determination of S-(+)- and R-(-)-ondansetron in human serum using derivatized cyclodextrin-modified capillary electrophoresis and solid-phase extraction. | A high-performance capillary electrophoresis (HPCE) assay method for the quantitation of S-(+)- and R-(-)-ondansetron in human serum was developed. Resolution was achieved using 15 mM heptakis-(2, 6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD) in 100 mM phosphate buffer (pH 2.5). A 72-cm untreated fused-silica capillary... |
9135318 | Pregnenolone sulphate and pregnenolone do not interact with 5 beta-pregnanolone- and hexobarbitone-induced anaesthesia in the rat. | We have studied the interaction of pregnenolone sulphate and pregnenolone with 5 beta-pregnanolone- and hexobarbitone-induced anaesthesia in male rats using an EEG threshold method. Burst suppression of the EEG of 1 s or more ("silent second" (SS)), was used as a criterion of deep anaesthesia. The effects of the steroi... |
9135138 | Receptor co-operation in retrovirus entry: recruitment of an auxiliary entry mechanism after retargeted binding. | We have constructed Moloney murine leukemia virus (MoMLV)-derived envelope glycoproteins (AMO) displaying an amino-terminal Ram-1-binding domain in which a variety of different amino acid spacers have been inserted between the displayed domain and the MoMLV surface (SU) subunit. Titres of retroviruses generated with th... |
9130375 | Influence of diffusion to fractal surfaces on the binding kinetics for antibody-antigen, analyte-receptor, and analyte-receptorless (protein) systems. | The diffusion-limited binding kinetics of antigen-antibody, ligand-receptor, analyte-receptorless systems for biosensor applications is analyzed within a fractal framework. The analysis presented applies equally well to these types of systems. For example, for the binding of 2-(p-toluidiny)-naphthalene-6-sulfonic acid ... |
9126246 | A highly conserved region of the Sendai virus nucleocapsid protein contributes to the NP-NP binding domain. | The nucleocapsid protein (NP) of Sendai virus is an essential component of both the nucleocapsid template and the NP-NP and NP0-P protein complexes required for viral RNA replication. When expressed alone in mammalian cells NP self-assembles into nucleocapsid-like particles which appear to contain cellular RNA. To iden... |
9114491 | Isolation, characterization and comparison of a novel crustacean toxin with a mammalian toxin from the venom of the scorpion Centruroides noxius Hoffmann. | A novel crustacean-specific toxin, Cn5, containing 66 amino acid residues was isolated from the venom of the scorpion Centruroides noxius Hoffmann. It is stabilized by four disulfide bridges, formed between Cys12-Cys65, Cys16-Cys41, Cys25-Cys46 and Cys29-Cys48. Toxicity tests revealed that Cn5 is a toxin that affects a... |
9114190 | Nosocomial bacteremia in critically ill patients: a multicenter study evaluating epidemiology and prognosis. Spanish Collaborative Group for Infections in Intensive Care Units of Sociedad Espanola de Medicina Intensiva y Unidades Coronarias (SEMIUC). | A total of 590 consecutive episodes of nosocomial bacteremia were prospectively followed in 30 intensive care units (ICUs) over a 9-month period. The crude and directly related mortality rates were 41.6% and 19%, respectively. The predominant pathogens were coagulase-negative staphylococci (24.4%) and coagulase-positiv... |
9108265 | Small-angle X-ray scattering analysis of pneumococcal lipoteichoic acid phase structure. | X-Ray-scattering analysis was performed on micelles of lipoteichoic acid from Streptococcus pneumoniae. This lipoteichoic acid differs from poly(glycerophosphate) and poly(glycosylglycerophosphate) lipoteichoic acids by a unique positively charged diacylglyceroglycolipid anchor and a complex structure of the hydrophili... |
9106365 | Potential virulence factors of Proteus bacilli. | The object of this review is the genus Proteus, which contains bacteria considered now to belong to the opportunistic pathogens. Widely distributed in nature (in soil, water, and sewage), Proteus species play a significant ecological role. When present in the niches of higher macroorganisms, these species are able to e... |
9106364 | Microbial production of surfactants and their commercial potential. | Many microorganisms, especially bacteria, produce biosurfactants when grown on water-immiscible substrates. Biosurfactants are more effective, selective, environmentally friendly, and stable than many synthetic surfactants. Most common biosurfactants are glycolipids in which carbohydrates are attached to a long-chain a... |
9106362 | Genetic regulation of nitrogen metabolism in the fungi. | In the fungi, nitrogen metabolism is controlled by a complex genetic regulatory circuit which ensures the preferential use of primary nitrogen sources and also confers the ability to use many different secondary nitrogen sources when appropriate. Most structural genes encoding nitrogen catabolic enzymes are subject to ... |
9098866 | The oral absorption of micro- and nanoparticulates: neither exceptional nor unusual. | This mini-review covers some of the historical and recent arguments over the experimental evidence on the uptake by and translocation from the intestinal mucosa of microparticulates after oral administration. It is concluded that there is now no dispute over the fact that this is a normal occurrence. Particulate uptake... |
9096228 | The effect of ionic conditions on the conformations of supercoiled DNA. II. Equilibrium catenation. | We studied the equilibrium formation of DNA catenanes to assess the conformational properties of supercoiled DNA as a function of ionic conditions and supercoiling density. Catenanes were formed by cyclizing linear DNA with long cohesive ends in the presence of supercoiled molecules. The efficiency of the catenation de... |
9096219 | Novel knowledge-based mean force potential at atomic level. | We present a new approach at the atomic level for the development of knowledge-based mean force potentials (MFPs) that can be used in fold recognition, ab initio structure prediction, comparative modelling and molecular recognition. Our method is based on atom-type definitions, raising the total frequency of the pairwi... |
9095612 | [A case of leukocytosis after massive blood transfusion for postpartum hemorrhagic shock]. | We experienced the perioperative management of a hemorrhagic shock associated with postpartum uterine rupture. After the emergency abdominal total hysterectomy, massive blood transfusion was required to maintain the hemodynamics and the laparotomy for hemostasis was performed on the 1st, 2nd and 7th ICU day. Total amou... |
9095359 | Chemoenzymatic synthesis and lectin binding properties of dendritic N-acetyllactosamine. | Proof that multivalency amplifies individual carbohydrate-protein interactions is growing. N-Acetylglucosamine (GlcNAc)-based dendrimers with valencies of two (9), four (10), and eight (11) were prepared in fair to excellent yields (65-99%) on the basis of the rational scaffolding of L-lysine on solid phase using estab... |
9095123 | Evidence for early supply independent mitochondrial dysfunction in patients developing multiple organ failure after trauma. | <h4>Objective</h4>To determine whether early supply independent mitochondrial oxidative dysfunction occurs in trauma patients who develop multiple organ failure (MOF).<h4>Design</h4>Prospective focused observational trial.<h4>Methods</h4>High-risk patients were aggressively resuscitated while being continuously monitor... |
9094738 | Interresidue interactions in protein classes. | The free energy difference between folded and unfolded state is about the same for most proteins and it is not more than the energy of a few noncovalent interactions. In addition to the numerous noncovalent interactions, some proteins contain one or more disulfide bonds, which, as covalent crosslinks, significantly sta... |
9092627 | Characterization of nuclear proteins that bind to the regulatory TGATTGGC motif in the human immunodeficiency virus type 1 long terminal repeat. | We have recently elucidated the nature and function of transcription factors present in Jurkat, glial and neuronal cells that interact with modulatory region B, the nuclear receptor responsive element, in the long terminal repeat of human immunodeficiency virus type 1 (HIV-1). Considering the key role that the combinat... |
9093048 | Malignant vasovagal syncope: a randomised trial of metoprolol and clonidine. | <h4>Objective</h4>To evaluate the efficacy of head up tilt guided treatment with metoprolol and clonidine in preventing the recurrence of syncope in patients with malignant vasovagal syncope.<h4>Patients</h4>20 patients (9 men and 11 women, mean age 33 (SD 17), range 14 to 62 years) with severe symptoms.<h4>Design</h4>... |
9092704 | Impermeant antitumor sulfonylurea conjugates that inhibit plasma membrane NADH oxidase and growth of HeLa cells in culture. Identification of binding proteins from sera of cancer patients. | The antitumor sulfonylurea LY237868 (N-(4-aminophenyl-sulfonyl)-N'-(4-chlorophenyl)urea) was conjugated through the A ring to alpha-cyclodextrin or agarose bead material (Affigel 10) to prepare impermeant conjugates for activity measurements and affinity isolation of binding proteins from serum. When conjugated to alph... |
9089437 | Locating the anion-selectivity filter of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. | The cystic fibrosis transmembrane conductance regulator forms an anion-selective channel; the site and mechanism of charge selectivity is unknown. We previously reported that cysteines substituted, one at a time, for Ile331, Leu333, Arg334, Lys335, Phe337, Ser341, Ile344, Arg347, Thr351, Arg352, and Gln353, in and flan... |
9089430 | ANLIZE: a molecular mechanics force field visualization tool and its application to 18-crown-6. | We describe a software tool that allows one to visualize and analyze the importance of each individual steric interaction in a molecular mechanics force field. ANLIZE is presently implemented for the Dreiding force field for use with the Cerius2 software package, but could be implemented in any molecular mechanics pack... |
9089214 | Neuroprotective effects of the novel brain-penetrating pyrrolopyrimidine antioxidants U-101033E and U-104067F against post-ischemic degeneration of nigrostriatal neurons. | A 10-min period of bilateral carotid occlusion (BCO)-induced forebrain ischemia in gerbils triggers a delayed retrograde degeneration of 35-40% of dopaminergic nigrostriatal (NS) neurons. The mechanism of the NS degeneration is believed to involve oxygen radical formation secondary to a postischemic increase in dopamin... |
9087440 | Molecular cloning and functional characterization of the receptor for Clostridium perfringens enterotoxin. | A cDNA encoding the Clostridium perfringens enterotoxin receptor gene (CPE-R) was cloned from an expression library of enterotoxin-sensitive Vero cells. The nucleotide sequence of CPE-R showed that the enterotoxin receptor consists of 209 amino acids with a calculated molecular mass of 22,029 D. This receptor is highly... |
9073358 | Analysis of 12-oxo-phytodienoic acid enantiomers in biological samples by capillary gas chromatography-mass spectrometry using cyclodextrin stationary phases. | The octadecanoid plant growth regulator 12-oxo-phytodienoic acid (12-oxo-PDA), which is also an intermediate in the biosynthesis of jasmonic acid, is obtained from 13-hydroperoxylinolenic acid via an unstable allene oxide generated by the enzyme allene oxide synthase. Recombinant, bacterially expressed and purified all... |
9073357 | Charge-transfer chromatographic study of the complex formation of some steroidal drugs with carboxymethyl-gamma-cyclodextrin. | The interaction between 15 steroidal drugs and carboxymethyl-gamma-cyclodextrin (CM-gamma-CD) was studied by reversed-phase charge-transfer thin-layer chromatography and the relative strength of interaction was calculated. CM-gamma-CD formed inclusion complexes with each compound, the complex always being less hydropho... |
9073355 | Matrix-assisted laser desorption ionization time-of-flight mass spectrometry as a rapid quality control method in oligonucleotide synthesis. | Oligonucleotide synthesis is a major activity for a large number of laboratories throughout the world. Dimethoxytrityl-deprotection monitors on instruments give the operator a measure of synthetic efficiency, but cannot be considered as a reliable indicator of the final quality of the cleaved and deprotected oligonucle... |
9125172 | Adenosine A3 receptor agonists protect HL-60 and U-937 cells from apoptosis induced by A3 antagonists. | The effects of novel, selective adenosine (ADO) A3 receptor antagonists of diverse structure on cells of the human HL-60 leukemia and U-937 lymphoma cell lines were examined. Both 3-ethyl 5-benzyl 2-methyl-6-phenyl-4-phenylethynyl-1,4-(+/-)-dihydropyridine-3, 5-dicarboxylate (MRS 1191, 0.5 microM) and 6-carboxy-methyl-... |
9086588 | Chiral gas chromatographic determination of ephedrine-type alkaloids in dietary supplements containing Má Huáng. | Má Huáng is a traditional Chinese medicine derived from the aerial parts of several Ephedra species (Ephedraceae). These plants produce (-)-ephedrine, (+)-pseudoephedrine, (-)-norephedrine, (+)-norpseudoephedrine, (-)-N-methylephedrine, and (+)-N-methylpseudoephedrine. Racemic and (-)-ephedrine, (+)-pseudoephedrine, an... |
9124601 | Gelatinases in epithelial lining fluid of patients with adult respiratory distress syndrome. | Gelatinases A and B are matrix metalloproteinases secreted as inactive pro forms and are capable of degrading basement membrane components after activation in the extracellular environment. To determine whether the presence of gelatinases A (noninflammatory cells) and B (inflammatory cells) in epithelial lining fluid (... |
9085557 | Varying effects of cyclodextrin derivatives on aggregation and thermal behavior of insulin in aqueous solution. | Maltosyl-beta-cyclodextrin (G2-beta-CyD) suppressed the aggregation of insulin in neutral solution, while the sulfate of beta-CyD (S-beta-CyD) accelerated the aggregation. On the other hand, the sulfobutyl ether of beta-CyD (SBE-beta-CyD) showed varying effects on insulin aggregation, depending on the degree of substit... |
9079642 | DNA binding and bending by the human papillomavirus type 16 E2 protein. Recognition of an extended binding site. | The human papillomavirus (HPV) 16 E2 protein (hE2) binds to four sites present upstream of the P97 promoter and regulates transcription of the viral E6 and E7 oncogenes. We have determined the relative binding constants for the interaction of the full-length hE2 protein with these sites. Our results show that hE2 binds... |
9118228 | Topological selectivity in Xer site-specific recombination. | The product topology of Xer-mediated site-specific recombination at plasmid sites has been determined. The product of deletion at pSC101 psi is a right-handed antiparallel 4-noded catenane. The ColE1 cer deletion product has an identical topology, except that only one pair of strands is exchanged. These specific produc... |
9119003 | The colchicine-binding and pyrene-excimer-formation activities of tubulin involve a common cysteine residue in the beta subunit. | Colchicine binding and pyrene excimer fluorescence of tubulin have been used to identify cysteine residue(s) essential for the colchicine binding activity of the protein. We report here that both the colchicine binding activity and the ability to form pyrene excimers of tubulin decay at an identical rate when the prote... |
9119000 | Three-dimensional structure in solution of the N-terminal lipoyl domain of the pyruvate dehydrogenase complex from Azotobacter vinelandii. | The three-dimensional structure of the N-terminal lipoyl domain of the acetyltransferase component of the pyruvate dehydrogenase complex from Azotobacter vinelandii has been determined using heteronuclear multidimensional NMR spectroscopy and dynamical simulated annealing. The structure is compared with the solution st... |
9075681 | Inducing cholesterol precipitation from pig bile with beta-cyclodextrin and cholesterol dietary supplementation. | <h4>Background/methods</h4>In this study, pigs fed for 3 weeks a well-balanced semi-purified diet enriched with 0.3% cholesterol and 0, 5 or 10% beta-cyclodextrin were proposed as new animal donors of gallbladder bile exhibiting different rates of cholesterol crystallization, in order to gain insight into the early mec... |
9116002 | Temperature-dependent behavior of bacteriochlorophyll and bacteriopheophytin in the photosynthetic reaction center from Rhodobacter sphaeroides. | We have reexamined the temperature dependence of resonance Raman (RR) spectra of the bacteriochlorin cofactors bound to reaction centers from Rhodobacter sphaeroides. Three types of resonant excitations were performed, namely, Soret band, bacteriopheophytin Qx-band, and near-infrared, Qy-band (pre)resonances. Sample te... |
9102459 | Binding, encapsulation and ejection: substrate dynamics during a chaperonin-assisted folding reaction. | Mitochondrial malate dehydrogenase (mMDH) folds more rapidly in the presence of GroEL, GroES and ATP than it does unassisted. The increase in folding rate as a function of the concentration of GroEL-ES reaches a maximum at a stoichiometry which is approximately equimolar (mMDH subunits:GroEL oligomer) and with an appar... |
9122156 | Virtual combinatorial libraries: dynamic generation of molecular and supramolecular diversity by self-assembly. | Molecular and supramolecular diversity may be generated, respectively, by reversible, covalent or noncovalent self-assembly of basic components whose various potential combinations in number and nature represent a virtual combinatorial library. This concept is applied to the induction of inhibitors of carbonic anhydras... |
9118960 | 1.9 A crystal structure of interleukin 6: implications for a novel mode of receptor dimerization and signaling. | Interleukin 6 (IL-6) has many biological activities in vivo, and deregulation has been implicated in many disease processes. IL-6, a 185 amino acid polypeptide was refolded, purified and crystallized. The crystals diffracted to beyond 1.9 A and the structure was solved using single isomorphous replacement. The X-ray st... |
9118952 | Identification of the molecular recognition sequence which determines the type-specific assembly of procollagen. | A key question relating to procollagen biosynthesis is the way in which closely related procollagen chains discriminate between each other to assemble in a type-specific manner. Intracellular assembly of procollagen occurs via an initial interaction between the C-propeptides followed by vectorial propagation of the tri... |
9069283 | Responsive gels formed by the spontaneous self-assembly of peptides into polymeric beta-sheet tapes. | Molecular self-assembly is becoming an increasingly popular route to new supramolecular structures and molecular materials. The inspiration for such structures is commonly derived from self-assembling systems in biology. Here we show that a biological motif, the peptide beta-sheet, can be exploited in designed oligopep... |
9068081 | Reduced PAF-acetylhydrolase activity is associated with postinjury multiple organ failure. | Our basic laboratory work has identified the postischemic gut as a source of platelet-activating factor (PAF), which primes circulating neutrophils for the production of reactive oxygen metabolites (ROMs) leading to distant organ injury. Circulating PAF-acetylhydrolase (PAF-AH) hydrolyzes PAF to lyso-PAF. Recently, ROM... |
9148766 | Secretory processing of amyloid precursor protein is inhibited by increase in cellular cholesterol content. | Plasma-membrane composition plays a crucial role in most of the cellular functions that depend on membrane processes. In virtually all cell types the proteolytic processing of Alzheimer amyloid precursor protein (APP) to generate soluble APP (sAPP) is believed to occur at the plasma membrane or in its immediate proximi... |
9065788 | Identification of sequence similarity between 60 kDa and 70 kDa molecular chaperones: evidence for a common evolutionary background? | Recent findings support the premise that chaperonins (60 kDa stress-proteins) and alpha-subunits of F-type ATPases (alpha-ATPase) are evolutionary related protein families. Two-dimensional gel patterns of synthesized proteins in unstressed and heat-shocked embryonic Drosophila melanogaster SL2 cells revealed that antib... |
9062354 | Neonatal treatment of rats with the neuroactive steroid tetrahydrodeoxycorticosterone (THDOC) abolishes the behavioral and neuroendocrine consequences of adverse early life events. | Stressful experience during early brain development has been shown to produce profound alterations in several mechanisms of adaptation, while several signs of behavioral and neuroendocrine impairment resulting from neonatal exposure to stress resemble symptoms of dysregulation associated with major depression. This stu... |
9055995 | In vitro activities of voriconazole (UK-109,496) against fluconazole-susceptible and -resistant Candida albicans isolates from oral cavities of patients with human immunodeficiency virus infection. | The susceptibility of Candida albicans to a new antifungal triazole, voriconazole (UK-109,496), was investigated in 105 isolates obtained from the oral cavities of patients with human immunodeficiency virus (HIV) infection to study this drug's activity against fluconazole-susceptible and -resistant isolates. MICs were ... |
9055070 | MDP1, a Saccharomyces cerevisiae gene involved in mitochondrial/cytoplasmic protein distribution, is identical to the ubiquitin-protein ligase gene RSP5. | Alteration of the subcellular distribution of Mod5p-I, a tRNA modification enzyme, member of the sorting isozyme family, affects tRNA-mediated nonsense suppression. Altered suppression efficiency was used to identify MDP genes, which, when mutant, change the mitochondrial/cytosolic distribution of Mod5p-I,KR6. MDP2 is ... |
9138585 | Manipulation of individual viruses: friction and mechanical properties. | We present our results on the manipulation of individual viruses using an advanced interface for atomic force microscopes (AFMs). We show that the viruses can be dissected, rotated, and translated with great facility. We interpret the behavior of tobacco mosaic virus with a mechanical model that makes explicit the comp... |
9138582 | A new molecular model for collagen elasticity based on synchrotron X-ray scattering evidence. | Collagen is the most abundant structural protein in vertebrates. The specific shape of its stress-strain curve is crucial for the function of a number of organs. Although the macroscopic mechanical behavior of collagen is well known, there is still no explanation of the elastic process at the supramolecular level. We h... |
9138581 | Thermodynamic and structural analysis of microtubule assembly: the role of GTP hydrolysis. | Different models have been proposed that link the tubulin heterodimer nucleotide content and the role of GTP hydrolysis with microtubule assembly and dynamics. Here we compare the thermodynamics of microtubule assembly as a function of nucleotide content by van't Hoff analysis. The thermodynamic parameters of tubulin a... |
9138554 | Molecular dynamics simulations of six different fully hydrated monomeric conformers of Escherichia coli re-lipopolysaccharide in the presence and absence of Ca2+. | Six previously published conformational models of Escherichia coli Re lipopolysaccharide (ReLPS) were subjected to molecular dynamics simulations using the CHARMM force field. The monomers of ReLPS were completely immersed in a water box. The dynamic behavior of the solvated models in the presence and absence of calciu... |
9138553 | Probing protein hydration and conformational states in solution. | The addition of polyethylene glycol (PEG), of various molecular weights, to solutions bathing yeast hexokinase increases the affinity of the enzyme for its substrate glucose. The results can be interpreted on the basis that PEG acts directly on the protein or indirectly through water activity. The nature of the effects... |
9050834 | A mixed-charge pair in human interleukin 4 dominates high-affinity interaction with the receptor alpha chain. | Human interleukin 4 (IL-4) binds to its cellular receptor with a Kd in the subnanomolar range, similar to many other 4-helix-bundle proteins interacting with members of the hematopoietin (cytokine) receptor superfamily. In the IL-4 system this interaction is predominantly determined by the extracellular domain (IL4-BP)... |
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