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10919870 | Effects of ultraviolet modification on the gating energetics of cyclic nucleotide-gated channels. | Middendorf et al. (Middendorf, T.R., R.W. Aldrich, and D.A. Baylor. 2000. J. Gen. Physiol. 116:227-252) showed that ultraviolet light decreases the current through cloned cyclic nucleotide-gated channels from bovine retina activated by high concentrations of cGMP. Here we probe the mechanism of the current reduction. T... |
10816570 | A possible role for caveolin as a signaling organizer in olfactory sensory membranes. | Fast kinetics and sensitivity of olfactory signaling raise the question of whether the participating proteins may be associated in supramolecular transduction complexes. We found evidence that caveolin proteins could play an important role in organizing signaling elements in olfactory sensory neurons. Western blot anal... |
10919790 | Comparative characterization of complete and truncated forms of Lactobacillus amylovorus alpha-amylase and role of the C-terminal direct repeats in raw-starch binding. | Two constructs derived from the alpha-amylase gene (amyA) of Lactobacillus amylovorus were expressed in Lactobacillus plantarum, and their expression products were purified, characterized, and compared. These products correspond to the complete (AmyA) and truncated (AmyADelta) forms of alpha-amylase; AmyADelta lacks th... |
10913311 | Molecular recognition of cAMP by an RNA aptamer. | Two classes of RNA aptamers that bind the second messenger adenosine 3',5'-cyclic monophosphate (cAMP; 1) were isolated from a random-sequence pool using in vitro selection. Class I and class II aptamers are formed by 33- and 31-nucleotide RNAs, respectively, and each is comprised of similar stem-loop and single-strand... |
10913284 | Sticky-end assembly of a designed peptide fiber provides insight into protein fibrillogenesis. | Coiled-coil motifs provide simple systems for studying molecular self-assembly. We designed two 28-residue peptides to assemble into an extended coiled-coil fiber. Complementary interactions in the core and flanking ion-pairs were used to direct staggered heterodimers. These had "sticky-ends" to promote the formation o... |
10913184 | Physical association of eukaryotic initiation factor 4G (eIF4G) with eIF4A strongly enhances binding of eIF4G to the internal ribosomal entry site of encephalomyocarditis virus and is required for internal initiation of translation. | Mammalian eukaryotic initiation factor 4GI (eIF4GI) may be divided into three similarly sized regions. The central region (amino acids [aa] 613 to 1090) binds eIF3, eIF4A, and the encephalomyocarditis virus (EMCV) internal ribosomal entry site (IRES) and mediates initiation on this RNA. We identified the regions of eIF... |
10908357 | Recognition of a cognate RNA aptamer by neomycin B: quantitative evaluation of hydrogen bonding and electrostatic interactions. | Aminoglycosides are an important class of antibiotic that selectively target RNA structural motifs. Recently we have demonstrated copper derivatives of amino-glycosides to be efficient cleavage agents for cognate RNA motifs. To fully develop their potential as pharmaceutical agents it is necessary to understand both th... |
10908293 | Partial agonism through a zinc-Ion switch constructed between transmembrane domains III and VII in the tachykinin NK(1) receptor. | Partly due to lack of detailed knowledge of the molecular recognition of ligands the structural basis for partial versus full agonism is not known. In the beta(2)-adrenergic receptor the agonist binding site has previously been structurally and functionally exchanged with an activating metal-ion site located between As... |
10906201 | Evasion of host defenses by measles virus: wild-type measles virus infection interferes with induction of Alpha/Beta interferon production. | Measles is a highly contagious disease currently responsible for over one million childhood deaths, particularly in the developing world. Since alpha/beta interferons (IFNs) are pivotal players both in nonspecific antiviral immunity and in specific cellular responses, their induction or suppression by measles virus (MV... |
10906193 | Definition of five new simian immunodeficiency virus cytotoxic T-lymphocyte epitopes and their restricting major histocompatibility complex class I molecules: evidence for an influence on disease progression. | Simian immunodeficiency virus (SIV) infection of the rhesus macaque is currently the best animal model for AIDS vaccine development. One limitation of this model, however, has been the small number of cytotoxic T-lymphocyte (CTL) epitopes and restricting major histocompatibility complex (MHC) class I molecules availabl... |
10903506 | Organization-dependent effects of toxic bivalent ions microtubule assembly and glycolysis. | The effects of bivalent ions on tubulin dynamics and the upper phase of glycolysis were investigated at different organization levels in vitro. Cu2+, Cd2+, Hg2+ and CrO4(2-) inhibit the tubulin polymerization at an IC50 of 14-24 microM with high cooperativity and also induce microtubule disassembly. The apparent bindin... |
10903151 | Structure-function studies on hsp47: pH-dependent inhibition of collagen fibril formation in vitro. | Hsp47, a 47 kDa heat shock protein whose expression level parallels that of collagen, has been regarded as a collagen-specific molecular chaperone. Studies from other laboratories have established the association of Hsp47 with the nascent as well as the triple-helical procollagen molecule in the endoplasmic reticulum a... |
10903142 | Fusion of the tissue factor extracellular domain to a tumour stroma specific single-chain fragment variable antibody results in an antigen-specific coagulation-promoting molecule. | Solid tumours growing beyond a size of 1-2 mm in diameter induce supporting connective tissue structures, the tumour stroma, comprising activated fibroblasts and newly formed blood vessels, embedded in an extracellular matrix. The selective destruction of this tissue or the inhibition of its function (e.g. tumour neoan... |
10899862 | Differential protein expression in phenotypic variants of Streptococcus pneumoniae. | Streptococcus pneumoniae undergoes spontaneous phase variation resulting in opaque and transparent colony forms. Differences in colony opacity correlate with differences in virulence: the transparent variants are more capable of colonizing the nasopharynx, whereas the opaque variants show increased virulence during sys... |
10900542 | Studies of floating dosage forms of furosemide: in vitro and in vivo evaluations of bilayer tablet formulations. | For the purpose of enhancement the bioavailability of furosemide (FR), a floating dosage form with controlled release of FR was designed in this study. Because of the lower solubility of active material in the gastric medium, it was first enhanced by preparing an inclusion complex of FR with beta-cyclodextrin (beta-CD)... |
10898669 | In vitro and in vivo activities of SCH 56592 (posaconazole), a new triazole antifungal agent, against Aspergillus and Candida. | SCH 56592 (posaconazole), a new triazole antifungal agent, was tested in vitro, and its activity was compared to that of itraconazole against 39 Aspergillus strains and to that of fluconazole against 275 Candida and 9 Cryptococcus strains. The SCH 56592 MICs for Aspergillus ranged from </=0.002 to 0.5 microg/ml, and th... |
10898160 | Simultaneous stereoselective analysis of venlafaxine and O-desmethylvenlafaxine enantiomers in clinical samples by capillary electrophoresis using charged cyclodextrins. | Capillary electrophoresis (CE) was used for the simultaneous chiral determination of venlafaxine (Vx), a new antidepressant drug and its main active metabolite. O-desmethyl venlafaxine (ODV). Among the charged cyclodextrins (CD) tested, phosphated gamma-CD was the most appropriate. Resolution of Vx and ODV was obtained... |
10898152 | Study of beta-blockers/beta-cyclodextrins inclusion complex by NMR, DSC, X-ray and SEM investigation. | The formation of inclusion complexes between beta-cyclodextrin with the two beta-blockers, atenolol and celiprolol, have been studied in the aqueous environment and in the solid state by nuclear magnetic resonance (NMR) spectroscopy, X-ray, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) ... |
10898151 | 1H-NMR and molecular modelling techniques for the investigation of the inclusion complex of econazole with alpha-cyclodextrin in the presence of malic acid. | Carrying on a study where the combination of alpha-cyclodextrin and malic acid was found to be the most effective in improving the solubility of econazole, an antifungal drug very poorly water soluble, in the present work 1H-NMR and nuclear overhauser effect (NOE) experiments and molecular modelling studies were perfor... |
10894719 | Self-assembly of the Agrobacterium tumefaciens VirB11 traffic ATPase. | The Agrobacterium tumefaciens VirB11 ATPase is a component of a type IV transporter dedicated to T-DNA delivery to plant cells. In this study, we tested a prediction from genetic findings that VirB11 self-associates in vivo. A chimeric protein composed of VirB11 fused to the DNA binding domain of lambda cI repressor pr... |
10891503 | Identification of the cytolinker plectin as a major early in vivo substrate for caspase 8 during CD95- and tumor necrosis factor receptor-mediated apoptosis. | Caspase 8 plays an essential role in the execution of death receptor-mediated apoptosis. To determine the localization of endogenous caspase 8, we used a panel of subunit-specific anti-caspase 8 monoclonal antibodies in confocal immunofluorescence microscopy. In the human breast carcinoma cell line MCF7, caspase 8 pred... |
10891499 | Nup50, a nucleoplasmically oriented nucleoporin with a role in nuclear protein export. | We present here a detailed analysis of a rat polypeptide termed Nup50 (formerly NPAP60) that was previously found to be associated with the nuclear pore complex (F. Fan et al., Genomics 40:444-453, 1997). We have found that Nup50 (and/or a related 70-kDa polypeptide) is present in numerous rat cells and tissues. By imm... |
10888634 | Effect of the murine leukemia virus extended packaging signal on the rates and locations of retroviral recombination. | Reverse transcriptase (RT) switches templates frequently during DNA synthesis; the acceptor template can be the same RNA (intramolecular) or the copackaged RNA (intermolecular). Previous results indicated that intramolecular template switching occurred far more frequently than intermolecular template switching. We hypo... |
10888633 | CCR8 on human thymocytes functions as a human immunodeficiency virus type 1 coreceptor. | To determine whether human immunodeficiency virus type 1 (HIV-1) coreceptors besides CXCR4 and CCR5 are involved in HIV-1 infection of the thymus, we focused on CCR8, a receptor for the chemokine I-309, because of its high expression in the thymus. Similar levels of CCR8 mRNA were detected in immature and mature primar... |
10888627 | Ectodomain of coxsackievirus and adenovirus receptor genetically fused to epidermal growth factor mediates adenovirus targeting to epidermal growth factor receptor-positive cells. | Human adenovirus (Ad) is extensively used for a variety of gene therapy applications. However, the utility of Ad vectors is limited due to the low efficiency of Ad-mediated gene transfer to target cells expressing marginal levels of the Ad fiber receptor. Therefore, the present generation of Ad vectors could potentiall... |
10888612 | Identification of a gammaherpesvirus selective chemokine binding protein that inhibits chemokine action. | Chemokines are involved in recruitment and activation of hematopoietic cells at sites of infection and inflammation. The M3 gene of gammaHV68, a gamma-2 herpesvirus that infects and establishes a lifelong latent infection and chronic vasculitis in mice, encodes an abundant secreted protein during productive infection. ... |
10888608 | Herpes simplex virus type 1 glycoprotein E domains involved in virus spread and disease. | Herpes simplex virus type 1 (HSV-1) glycoprotein E (gE) functions as an immunoglobulin G (IgG) Fc binding protein and is involved in virus spread. Previously we studied a gE mutant virus that was impaired for IgG Fc binding but intact for spread and another that was normal for both activities. To further evaluate the r... |
10881031 | Nicotine-induced excitation of locus coeruleus neurons is blocked by elevated levels of endogenous kynurenic acid. | The present electrophysiological study shows that manipulation with endogenous brain kynurenic acid (KYNA) is able to affect the response of central noradrenergic neurons to nicotine. Previous studies have shown that systemically administered nicotine in low doses is associated with a marked, but short-lasting increase... |
10828287 | Exploring the nature of molecular recognition in nicotinic acetylcholine receptors. | Nicotinic acetylcholine receptors (nAChRs) are the subject of ever increasing interest because of their presumed involvement in the etiology of numerous clinical disorders. Unfortunately, the absence of atomic-level structural data, as well as the pharmacological complexity of these receptors leaves many fundamental qu... |
10819220 | Enantioselective determination of persistent and partly degradable toxaphene congeners in high trophic level biota. | Enantiomer separation of chiral toxaphene components in biological samples was studied by application of different chiral stationary phases based on modified cyclodextrins. Several pairs of enantiomers were resolved on permethylated beta-cyclodextrin (beta-PMCD), among them 2-endo,3-exo,5-endo,6-exo,8,8,9,10-octachloro... |
11001588 | DNA loops and semicatenated DNA junctions. | <h4>Background</h4>Alternative DNA conformations are of particular interest as potential signals to mark important sites on the genome. The structural variability of CA microsatellites is particularly pronounced; these are repetitive poly(CA). poly(TG) DNA sequences spread in all eukaryotic genomes as tracts of up to 6... |
23105257 | Inhibitory effect of metalloporphyrins in conjunction with cholesterol on hepatic phospholipase A(2) activityin vivo in rats. | We investigated the effect of cholesterol and the metalloporphyrins cobalt mesoporphyrin (CoMP) and chromium protoporphyrin (CrPP) on phospholipase A(2) (PLA(2)) activity and the consequent hepatic mitochondrial stability as well as on lipid concentrations. Our studies revealed that on administration of cholesterol, Cr... |
18968027 | Silver(I) ion selective PVC membrane based on bis-pyridine tetramide macrocycle. | A PVC membrane based on bis-pyridine tetramide macrocycle exhibits a good response for silver ion over a wide concentration range (1.0x10(-1)-4.0x10(-5) mol l(-1)). The electrode has a relatively fast response time and can be used for more than 5 months without observing any divergence. High selectivity for Ag(+) ions ... |
10991263 | Excitonic funneling in extended dendrimers with nonlinear and random potentials | The mean first passage time (MFPT) for photoexcitations diffusion in a funneling potential of artificial treelike light-harvesting antennas (phenylacetylene dendrimers with generation-dependent segment lengths) is computed. Effects of the nonlinearity of the realistic funneling potential and slow random solvent fluctua... |
10961399 | Molecular batteries: ferrocenylsilylation of dendrons, dendritic cores, and dendrimers: new convergent and divergent routes to ferrocenyl dendrimers with stable redox activity | The ferrocenylsilylation of the phenol triallyl dendron 2, of the phenol nonaallyl dendron 4, and of the 9-, 27-, 81-, and 243-allyl dendrimers 7-10 (monitored by the disappearance of the signals of the olefinic protons in 1H NMR spectra) has been achieved using ferrocenyldimethylsilane 1 and Karstedt's catalyst in die... |
10961396 | Cyanide-bridge Fe-Fe and Fe-Co molecular squares: structures and electrochemistry of | Cyanide-bridged iron-iron and iron--cobalt molecular squares of [Fe(II/4)(mu-CN)4(bpy)8[(PF6)4 x 4H2O (1), [Fe(II/2)Co(II/2)(mu-CN)4(bpy)8](PF6)4 x 3CHCl3 x 2CH3CN (2), and [Fe(II/2)Co(III/2)(mu-CN)4(bpy)8](PF6)6 x 2CHCl3 x 4CH3NO2 (3) (bpy =2,2'-bipyridine) were prepared. X-ray structure analyses for 1-3 were performe... |
10939748 | Stilbenoid dendrimers | The first five generations of the stilbenoid dendrimers 1(n) (n = 1-5) have been prepared by a combined coupled synthesis (between the generations of the dendrons 8-12) and convergent synthesis. Wittig-Horner reactions together with a protecting group technique yield monodisperse compounds of high constitutional and co... |
10939738 | Synthesis and an X-ray structure of soluble phenylacetylene macrocycles with two opposing bipyridine donor sites | The synthesis of the shape-persistent macrocycles 10a and 10b with two bipyridine units in opposing sides by Hagihara/Sonogashira cross-coupling chemistry of suitably functionalized building blocks is reported. X-ray analysis of single crystals of 10b shows a layered structure with channels filled with solvent molecule... |
10905337 | Inclusion of phthalate esters by a self-assembled monolayer of thiolated cyclodextrin on a gold electrode | Complexation of phthalic acid esters (PAEs) by a self-assembled monolayer (SAM) of thiolated alpha-cyclodextrin (6-(2-mercaptoethylamino)-6-deoxy-alpha-cyclodextrin, MEA-alpha-CD) on a gold electrode was examined by a cyclic voltammetry using hydroquinone (HQ) as a probe. From the inhibitory effect of the phthalate est... |
10905299 | A tandem ion trap/ion mobility spectrometer | A tandem quadrupole ion trap/ion mobility spectrometer (QIT/IMS) has been constructed for structural analysis based on the gas-phase mobilities of mass-selected ions. The instrument combines the ion accumulation, manipulation, and mass-selection capabilities of a modified ion trap mass spectrometer with gas-phase elect... |
10894535 | Self-directed growth of molecular nanostructures on silicon | Advances in techniques for the nanoscale manipulation of matter are important for the realization of molecule-based miniature devices with new or advanced functions. A particularly promising approach involves the construction of hybrid organic-molecule/silicon devices. But challenges remain--both in the formation of na... |
10891214 | Induced circular dichroism of cyclodextrin inclusion complexes: examining the cavity with a bilateral probe | The induced circular dichroism (ICD) of 1@7-Cy gives rise to an unusual spectrum which can be explained by a positive and a negative contribution of two identical chromophores. This finding is in agreement with rules predicting the ICD of chiral supramolecular systems. |
10891212 | Synthesis of Copper(I) catenanes incorporating a disulfide bridge and their deposition on a gold surface | The synthesis of two coordinating catenates with the ability to undergo surface-confined chemistry is described. For each catenate, one of the rings includes a 2,9-diphenyl-1,10-phenanthroline unit as a coordinating moiety and a disulfide bridge, which allows adsorption of the catenate onto a gold surface, thus going f... |
10891145 | Regioselective Monoalkylation of Calixarenes. Synthesis of Homodimer Calixarenes. | The selective monoalkylation at the smaller (lower) rim of the p-tert-butylcalix[4]- and -[6]arenes using bis(butyltin)oxide and different alkylating agents is described. The procedure is remarkable for the mild conditions used allowing an efficiently access to monoalkylated calixarene derivatives in moderate to good y... |
10891142 | Syntheses of Acetylenic Oligophenylene Macrocycles Based on a Novel Dewar Benzene Building Block Approach. | A general synthetic approach to strained p-phenylene-based acetylenic macrocycles is described. A key feature in this approach is exploitation of Dewar benzene as an angular p-phenylene synthon. Thus, 1,4-acetal-bridged 2,5-dichloro(Dewar benzene) 5, prepared in four steps from dimethyl acetylenedicarboxylate and 1,2-d... |
10891136 | Synthesis and Photochromism of Crowned Spirobenzothiapyran: Facilitated Photoisomerization by Cooperative Complexation of Crown Ether and Thiophenolate Moieties with Metal Ions. | Spirobenzothiapyrans bearing monoaza-12-crown-4, -15-crown-5, -18-crown-6, and oligooxyethylene moieties were synthesized, and their photochromism was examined in the presence of cations in acetonitrile. The cation complexation by their crown ether moieties cannot induce thermal isomerization to their corresponding col... |
10884679 | The use of PAMAM dendrimers in the efficient transfer of genetic material into cells. | Polyamidoamine (PAMAM) dendrimers have steadily grown in popularity in the past decade in a variety of disciplines, ranging from materials science to biomedicine. This can be attributed in part to their use in applications that range from computer toners to medical diagnostics. PAMAM dendrimers are safe and nonimmunoge... |
10884400 | Mimicking the antenna-electron transfer properties of photosynthesis. | A molecular assembly based on derivatized polystyrene is described, which mimics both the light-harvesting and energy-conversion steps of photosynthesis. The system is unique in that the two key parts of a photosynthetic system are incorporated in a functional assembly constructed from polypyridine complexes of Ru(II).... |
10860597 | Cationic Mixed Micelles in the Presence of beta-Cyclodextrin: A Host-Guest Study. | The conductances of trimethyltetradecylammonium bromide (TTAB)+triphenyltetradecylphosphonium bromide (TTPB) and TTAB+trimethylhexadecylammonium bromide (HTAB) over the entire mole fraction range of TTAB (alpha(TTAB)) were measured in water and in beta-cyclodextrin+water (CD+W) mixtures at fixed 4 and 8 mM of CD at 30 ... |
12541518 | [The separation of three basic drugs with carboxymethyl-poly-beta-cyclodextrin as chiral additive by capillary electrophoresis]. | Five cyclodextrin derivatives, namely phosphate ester beta-CD, carboxymethyl-beta-CD(CM-beta-CD), bis-[6-oxygen-(beta-carboxymethyl-succinic acid-4-ester)] beta-CD(F-CM-beta-CD), beta-CD polymer(P-beta-CD), carboxymethyl-poly-beta-CD (CD-P-beta-CD), were used as chiral selector for separation of three basic drugs, lobe... |
12541514 | [Preparation of gas chromatographic capillary columns with beta-cyclodextrin polymer stationary phase modified with methyl phenyl silicone(OV-17)]. | An insoluble beta-cyclodextrin polymer cross-linked with epichlorohydrin was prepared. beta-Cyclodextrin polymer (0.26 g) was treated for 0.5 h by a ultrasonator in the mixed solvent (10 mL) of isopropyl ether, methylene dichloride and benzene with a volume ratio 2:1:2, and a 26 g/L colloidal stationary liquid was prep... |
12541503 | Hydroxy-dibenzo crown ether stationary phase for capillary gas chromatography using sol-gel technology. | A new kind of crown ether, OH-dibenzo-14-crown-4 (OH-DB14C4), is prepared and coated onto the fused silica capillary by sol-gel process. Chromatographic characteristics including column efficiency (> 3,000 plates/m), thermal stability (to 330 degrees C) and ability of deactivation are studied. The selectivity of new st... |
11590489 | Therapeutic options for the management of oropharyngeal and esophageal candidiasis in HIV/AIDS patients. | Mucocutaneous candidiasis is frequently one of the first signs of HIV infection. Over 90% of patients with AIDS will develop oropharyngeal candidiasis at some time during their illness. Although numerous antifungal agents are available, azoles, both topical (clotrimazole) and systemic (fluconazole, itraconazole), have ... |
11421344 | Achievements and challenges of sialic acid research. | Slalic acids are one of the most important molecules of life, since they occupy the terminal position on macromolecules and cell membranes and are involved in many biological and pathological phenomena. The structures of sialic acids, comprising a family of over 40 neuraminic acid derivatives, have been elucidated. How... |
11379035 | [Beta-cyclodextrin inclusion complexes: effect of the host substitution on molecular recognition]. | The stability of inclusion complexes (i.e. the measure of molecular recognition between a guest and beta-cyclodextrin) is highly influenced by the fit of the guest into the cavity of the host and by the secondary bonds among the functional groups getting in close connection. The strength of these interactions depend on... |
11200458 | [Department of Protein Structure and Function--Volodimir Oleksandrovich Bielitser School of the Ukrainian Academy of Sciences. Studies on structure of fibrin fiber structure and mechanism (1975-1987]. | In this short historical review the records about foundation and research activity of the Department of Structure and Function of Protein--school of V. A. Belitser, Member of the National Academy of Sciences of Ukraine are presented. V. A. Belitser was the founder and indispensable chief of the department since the dat... |
10861218 | p40(phox) Participates in the activation of NADPH oxidase by increasing the affinity of p47(phox) for flavocytochrome b(558). | NADPH oxidase is one of the major components of the innate immune system and is used by phagocytes to generate microbicidal reactive oxygen species. Activation of the enzyme requires the participation of a minimum of five proteins, p22(phox), gp91(phox) (together forming flavocytochrome b(558)), p47(phox), p67(phox) an... |
11196868 | Synthesis and characterization of water-soluble silver(I) complexes with L-histidine (H2his) and (S)-(-)-2-pyrrolidone-5-carboxylic acid (H2pyrrld) showing a wide spectrum of effective antibacterial and antifungal activities. Crystal structures of chiral helical polymers [Ag(Hhis)]n and ([Ag(Hpyrrld)]2)n in the solid s... | Two water-soluble, silver(I) complexes showing a wide spectrum of effective antibacterial and antifungal activities, i.e., ([Ag(Hhis)].0.2EtOH)2 (1; H2his = L-histidine) and [Ag(Hpyrrld)]2 (3; H2pyrrld = (S)-(-)-2-pyrrolidone-5-carboxylic acid) were prepared. In aqueous solution 1 and 3 were present as dimers, whereas ... |
11196867 | Syntheses, structures, and properties of tetrakis(mu-acetato)dirhodium(II) complexes with axial pyridine nitrogen donor ligands with or without assistance of hydrogen bonds. | Eight adducts of Rh2(O2CCH3)4 with axial pyridine derivatives that contain hydrogen-bonding amino and/or steric methyl substituents in the 2- and 6-positions have been prepared and examined by electronic absorption and 1H NMR spectroscopy in solution and by elemental, IR, thermogravimetric, and X-ray diffraction analys... |
11196847 | Mechanistic studies of (porphinato)iron-catalyzed isobutane oxidation. Comparative studies of three classes of electron-deficient porphyrin catalysts. | We report herein a comprehensive study of (porphinato)iron [PFe]-catalyzed isobutane oxidation in which molecular oxygen is utilized as the sole oxidant; these catalytic reactions were carried out and monitored in both autoclave reactors and sapphire NMR tubes. In situ 19F and 13C NMR experiments, coupled with GC analy... |
11196846 | Supramolecular coordination chemistry in aqueous solution: lanthanide ion-induced triple helix formation. | The self-assembly of dinuclear triple helical lanthanide ion complexes (helicates), in aqueous solution, is investigated utilizing laser-induced, lanthanide luminescence spectroscopy. A series of dinuclear lanthanide (III) helicates (Ln(III)) based on 2,6-pyridinedicarboxylic acid (dipicolinic acid, dpa) coordinating u... |
11196900 | Supramolecular complex of cytochrome c with lariat ether: solubilization, redox behavior and catalytic activity of cytochrome c in methanol. | A variety of lariat ethers were employed to solubilize water-soluble cytochrome c in methanol, in which alcohol, ether, ester, amine, and amide functionalities were attached as cation-ligating side arms to 18-crown-6, 15-crown-5, and 12-crown-4 rings. Among these lariat ethers, the alcohol-armed 18-crown-6 derivative o... |
11196894 | A systematic evaluation of molecular recognition phenomena. 2. Interaction between phosphates and nucleotides with hexaazamacrocyclic ligands containing diethylic ether spacers. | The host-guest interactions between ortho- (Ph), pyro- (Pp), and tripolyphosphate (Tr) anions together with ATP (At), ADP (Ad), and AMP (Am) nucleotides and the two hexaazamacrocyclic ligands 1,15-dioxa-4,8,12,18,22,26-hexaazacyclooctacosane (Pn) and 1,13-dioxa-4,7,10,16,20,24-hexaazacyclohexacosane (Op) have been inve... |
11196893 | A systematic evaluation of molecular recognition phenomena. 1. Interaction between phosphates and nucleotides with hexaazamacrocyclic ligands containing m-xylylic spacers. | The host-guest interactions between ortho- (Ph), pyro- (Pp), and tripolyphosphate (Tr) anions together with ATP (At), ADP (Ad), and AMP (Am) nucleotides and the hexaazamacrocyclic ligand 3,7,11,19,23,27-hexaazatricyclo[27311(13,17)]triaconta- 1(32),13,15,17(34),29(33),30-hexaene (Bn) have been investigated by potentiom... |
11131144 | Isolation of a raw starch-binding fragment from barley alpha-amylase. | Barley alpha-amylase was purified by ammonium sulfate fraction, ion-exchange, ultrafiltration, and gel filtration to homogeneity. The purified enzyme was partially digested with trypsin, and the reaction mixture was applied to a cyclohepta-amylose epoxy Sepharose 6B column. Bound fragments were eluted by free cyclohept... |
11128993 | Roles of Eph receptors and ephrins in segmental patterning. | Eph receptor tyrosine kinases and their membrane-bound ligands, ephrins, have key roles in patterning and morphogenesis. Interactions between these molecules are promiscuous, but largely fall into two groups: EphA receptors bind to glycosylphosphatidyl inositol-anchored ephrin-A ligands, and EphB receptors bind to tran... |
11035538 | Ocular penetration of topical Delta9-tetrahydrocannabinol from rabbit corneal or cul-de-sac application site. | <h4>Purpose</h4>To determine the relative effects of low-volume drop placement either on the corneal surface or in the lower cul-de-sac on Delta9-tetrahydrocannabinol (THC) penetration into ocular fluids and tissues.<h4>Methods</h4>Pigmented rabbits received 10 microl drops in one eye at either application site. Care w... |
11038071 | Deflazacort increases laminin expression and myogenic repair, and induces early persistent functional gain in mdx mouse muscular dystrophy. | Deflazacort slows the progress of Duchenne muscular dystrophy (DMD) with fewer side effects than prednisone. In mdx mice, deflazacort treatment augments repair and growth of new muscle fibers. We tested the hypothesis that deflazacort improves muscle function and promotes repair by increasing myogenic cell proliferatio... |
11001097 | Binding of octa-plus porphyrazines to DNA. | We present a preliminary report of the interaction of octacationic N-methyl-pyridyl metalloporphyrazines, M=Cu(II) (Cupz+8) and Zn(II) (Znpz+8), with calf thymus DNA. These were monitored by electronic absorption spectroscopy, and in the case of Znpz+8, also by emission spectroscopy. These studies show that both the Cu... |
10999256 | Self-assembly and lyomesophases formed by long-chain alkoxymethyl-nucleobase derivatives. | Amphiphilic complementary nucleobase derivatives, containing n-octadecyloxymethyl substituents at the N1 position of pyrimidine and N9 of purine, dissolved in chloroform form non-specific lyotropic mesophases, which were analyzed by optical polarizing microscopy. Molecular modeling studies visualize hypothetical horizo... |
10994187 | [New cyclomaltodextrin-glucanotransferases, produced by Bacillus macerans]. | For the first time, microorganisms producing cyclomaltodextrin glucan transferases (CGT, EC 2.4.1.19) were isolated from soil samples of various ecogeographical regions. These microorganisms were identified as Bacillus macerans. The enzymes were purified by affinity chromatography on a alpha-cyclodextrin polymer and ge... |
10990208 | Hydrogen bonding and electrostatic interaction contributions to the interaction of a cationic drug with polyaspartic acid. | <h4>Purpose</h4>To determine the mechanism and identify forces of interaction between polyaspartic acid and diminazene (a model drug). Such knowledge is essential for the design of polymeric drug delivery systems that are based on molecular self-assembly into complexes or micellar type systems.<h4>Methods</h4>Complex f... |
10990200 | Proofs of the structure of lipid coated nanoparticles (SMBV) used as drug carriers. | <h4>Purpose</h4>Supramolecular Biovectors (SMBV) consist of cross-linked cationic nanoparticles surrounded by a lipid membrane. The purpose was to study the structure of the lipid membrane and to characterise its interaction with the nanoparticles in order to differentiate SMBV from other polymer/lipid associations.<h4... |
10990106 | Acute renal failure in the ICU: risk factors and outcome evaluated by the SOFA score. | <h4>Objectives</h4>To describe risk factors for the development of acute renal failure (ARF) in a population of intensive care unit (ICU) patients, and the association of ARF with multiple organ failure (MOF) and outcome using the sequential organ failure assessment (SOFA) score.<h4>Design</h4>Prospective, multicenter,... |
10989917 | Apolipoprotein A-I, phospholipid vesicles, and cyclodextrins as potential anti-atherosclerotic drugs: delivery, pharmacokinetics, and efficacy. | High-density lipoprotein (HDL) is a reliable predictor for susceptibility to cardiovascular disease. Since apolipoprotein A-I (apoA-I) is the major protein of HDL, it is worthwhile to evaluate the potential of this protein to reduce the lipid burden of lesions observed in the clinic. While a large body of data emanates... |
10976881 | Study of the keratinization process in human hair follicle by X-ray microdiffraction. | Synchrotron X-ray micro-diffraction studies along the follicle and the hair fibre allowed us to follow the keratinization process and the progressive organization of the keratin: i) molecular organization appeared progressively in the follicle; the formation of alpha-helices was completed inside the follicle. ii) supra... |
10976507 | Hydrogen bonding isosteres: bimolecular carboxylic acid and amine-N-oxide interactions mediated via CH...O hydrogen bonds. | The X-ray structures of cocrystals between 2,2'-dipyridyl-N,N'-dioxide (1) with fumaric acid (2), itaconic acid (3), succinic acid (4), and oxalic acid (5) were solved to determine if concurrent CH...O interactions were capable of orienting the bimolecular association of the two molecules. Cocrystals 1.2, 1.3 and 1.4 p... |
10965222 | Toxicity, uptake kinetics and efficacy of new transfection reagents: increase of oligonucleotide uptake. | Human arterial smooth muscle cell (haSMC) proliferation is stimulated by platelet-derived growth factor (PDGF) release of human arterial endothelial cells (haEC) whereas transforming growth factor-beta(1) (TGF-beta(1)) secretion by haSMC promotes extracellular matrix formation. Inhibitory concepts with antisense oligon... |
10963062 | Investigation of the metabolism of 14C/13C-practolol in rat using directly coupled radio-HPLC-NMR-MS. | 1. The metabolic fate of 14C/13C-practolol was investigated using on-line HPLC-NMR-MS following oral administration to rat. The major route of elimination for the radiolabel was via the urine with the principal biotransformation products confirmed as the 2-hydroxy- and 2-hydroxyglucronide metabolites. 2. In addition, f... |
10960181 | Hydrophobicity: is LogP(o/w) more than the sum of its parts? | The empirically calculated parameter LogP(o/w), the log(10) of the coefficient for solvent partitioning between 1-octanol and water, has been used to provide the key data for a unique non-covalent interaction force field called HINT (Hydropathic INTeractions). This experimentally-derived force field encodes entropic as... |
10961400 | Core modified meso-aryl corrole: first examples of CuII, NiII, CoII and RhI complexes. | A variety of metal complexes of 5,10,15-triphenyl-21-monooxa-corrole 4 have been investigated. This monooxa corrole, where one of the pyrrole ring is replaced by a furan moiety, is synthesized by the alpha-alpha coupling reaction of 16-oxa tripyrrane and dipyrromethane. The single crystal X-ray structure of 4 indicates... |
10961344 | Structure and function of the type 1 insulin-like growth factor receptor. | The type 1 insulin-like growth factor receptor (IGF-1R), a transmembrane tyrosine kinase, is widely expressed across many cell types in foetal and postnatal tissues. Activation of the receptor following binding of the secreted growth factor ligands IGF-1 and IGF-2 elicits a repertoire of cellular responses including pr... |
10961343 | The invasion-associated type III secretion system of Salmonella typhimurium: common and unique features. | Several bacterial pathogens make use of a specialized protein secretion system to inject effector proteins into host cells. This system, commonly referred to as type III secretion, is always associated with phenotypes related to intimate interactions between the pathogen and its respective host cells. The enteric patho... |
10961342 | Intracellular osmotic action. | Water often acts as a critical reactant in cellular reactions. Its role can be detected by modulating water activity with osmotic agents. We describe the principles behind this 'osmotic stress' strategy, and survey the ubiquity of water effects on molecular structures that have aqueous, solute-excluding regions. These ... |
10961308 | Highly selective separations by capillary electrochromatography: molecular imprint polymer sorbents. | Molecular imprint polymers (MIPs) are synthesized in the presence of a template, or 'imprint' molecule which results in the formation of specific recognition cavities complementary to the template in shape and chemical functionality. The resultant MIP then acts as a selective binding medium for the template molecule. T... |
10959858 | A novel route to the vinyl sulfide nine-membered macrocycle moiety of Griseoviridin. | The synthetic potentialities of cerium(III) chloride are demonstrated by the synthesis of a nine-membered ring heterocycle component of Griseoviridin (3) in optically active form. The key step involves the stereospecific formation of the alpha-carbalkoxy alkenyl sulfide moiety using a combination system of cerium(III) ... |
10959723 | Fimbriae-assisted bacterial surface display of heterologous peptides. | The display of peptide segments on the surface of bacteria offers many new and exciting applications in biotechnology and medical research. Fimbria-assisted display of heterologous sequences is a paradigm for chimeric organelle display on bacteria. Fimbriae are particularly attractive candidates for epitope display for... |
10953918 | In vivo gene delivery to the lung using polyethylenimine and fractured polyamidoamine dendrimers. | <h4>Background</h4>Gene transfer into the airways could be of importance for the treatment of chronic lung diseases such as cystic fibrosis. In the past few years several attempts have been made to effectively deliver DNA to the lung using different viral and non-viral vector systems. Viral vectors and cationic lipids ... |
10945967 | Self-assembly properties of recombinant engineered amelogenin proteins analyzed by dynamic light scattering and atomic force microscopy. | Dynamic light scattering (DLS) analysis together with atomic force microscopy (AFM) imaging was applied to investigate the supramolecular self-assembly properties of a series of recombinant amelogenins. The overall objective was to ascertain the contribution of certain structural motifs in amelogenin to protein-protein... |
10950281 | Resolution and identification of the protein components of the photosystem II antenna system of higher plants by reversed-phase liquid chromatography with electrospray-mass spectrometric detection. | Reversed-phase liquid chromatography (RPLC) was interfaced to mass spectrometry (MS) with an electrospray ion (ESI) source for the separation and accurate molecular mass determination of the individual intrinsic membrane proteins that comprise the photosystem II (PS II) major light-harvesting complex (LHC II) and minor... |
10949315 | Abiotic and enzymatic degradation of wheat straw cell wall: a biochemical and ultrastructural investigation. | The action of an abiotic lignin oxidant and a diffusible xylanase on wheat straw was studied and characterized at the levels of the molecular structures by chemical analysis and of the cell wall ultrastructure by transmission electron microscopy. While distinct chemical changes in the target polymers were observed when... |
10944780 | Effect of hydroxypropyl-beta-cyclodextrin on hydrocortisone dissolution from films intended for ocular drug delivery. | The formation of an inclusion complex between hydrocortisone and hydroxypropyl-beta-cyclodextrin can affect the in vitro transfer rate of hydrocortisone from the aqueous to the organic phase. The observed first order transfer rate constants showed that the complexation of hydrocortisone with hydroxypropyl-beta-cyclodex... |
10944779 | In vitro and in vivo evaluation of an amylobarbitone/hydroxypropyl-beta-cyclodextrin complex prepared by a freeze-drying method. | The complex formation of amylobarbitone (AMB) with 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was investigated in aqueous solution and in the solid state. The apparent stability constant for complex formation (Kc) calculated by phase solubility and spectral shift methods was 524 M-1 and 568 M-1, respectively. The s... |
10945676 | Determination of the substituent distribution in O-sulfonylbutyl-(1-->4)-glucans. | A method has been developed to determine the distribution of substituents in the glucose units of sulfonylbutylethers of cyclomaltoheptaose (beta-cyclodextrin). This method involves hydrolysis of the glucosidic linkages, permethylation, formation of sulfonylchlorides and subsequent transformation to the permethylated s... |
10945675 | Formation of unexpected substitution patterns in sulfonylbutylation of cyclomaltoheptaose promoted by host-guest interaction. | The distribution of substituents in sulfonylbutylethers of cyclomaltoheptaose (beta-cyclodextrin) formed in aqueous medium has been determined by gas chromatography after hydrolysis and formation of the permethylated sulfonylfluoride derivatives. In contrast to other etherification reactions of beta-cyclodextrin, prefe... |
10945672 | Complex permittivities of cyclomaltooligosaccharides (cyclodextrins) over microwave frequencies to 26 GHz. | Complex permittivities (epsilon*) for microwave radiation between 0.5 and 26 GHz have been determined for alpha-, beta-, and gamma-cyclodextrins in the solid state at room temperature. For the real component of epsilon*, maxima occur near 0.6 GHz, and the relation beta > alpha > gamma is evident across the full-frequen... |
10943942 | Using a heavy chain-loss hybridoma 26.4.1LL for studying the structural basis of immunoglobulin chain association. | One of the mechanisms contributing to antibody diversity is created by the association of different heavy and light chains. The combinability of heavy and light chains has been studied previously in two systems: in vitro chain recombination and hybrid hybridoma. Here, a novel in vivo chain combination assay system invo... |
10939747 | Electrostatic core shielding in dendritic polyglutamic porphyrins. | Polyglutamic dendritic porphyrins of the general formula H2PophGlu(N)OR (H2Porph = free-base meso-tetra-4-carboxyphenylporphyrin (H2TCPP), Glu=dendrimer layer composed of L-glutamates, N= 1-3: dendrimer generation number, R = terminal group (All, H)) were synthesized and characterized with NMR and MALDI-TOF mass spectr... |
10939734 | Structure and lipophilicity profile of 2,3-anhydro-alpha-cyclomannin and its ethanol inclusion complex. | Readily available from alpha-cyclodextrin in three steps, 2,3-anhydro-alpha-cyclomannin composed of six alpha-(1-->4)-linked 2,3-anhydro-D-mannopyranose residues, crystallizes well when precipitated from aqueous ethanol. An X-ray structure reveals the macrocycle to contain ethanol in its cavity, thus representing the f... |
10939465 | Optimised separation of endogenous urinary components using cyclodextrin-modified micellar electrokinetic capillary chromatography. | In this study both native and chemically modified cyclodextrins (CDs) were investigated as buffer additives to improve the micellar electrokinetic capillary chromatography (MEKC) separation of endogenous bioanalytes in human urine. The following CDs were investigated: alpha, beta, gamma-CDs; hydroxypropyl-alpha-CD, hyd... |
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