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6179948 | Discrete primary locations of a tyrosine-protein kinase and of three proteins that contain phosphotyrosine in virally transformed chick fibroblasts. | We have studied the localization of three abundant cellular proteins which are substrates for tyrosine protein kinases in virally transformed chicken embryo fibroblasts. The primary location of each substrate is unaltered by transformation with Rous sarcoma virus (RSV). The tyrosine-phosphorylated species is localized ... |
7050102 | Mouse procollagen IV. Characterization and supramolecular association. | The endodermal cell line PF-HR9, derived from the murine teratocarcinoma cell line PCC4-F, was grown as monolayers and as cell clusters called embryoid bodies. Procollagen IV and laminin were isolated from both kinds of culture media. Antibodies specific to collagen IV and to laminin demonstrated these materials in ass... |
6806377 | Noncovalent association of heavy and light chains of human immunoglobulins. III. Specific interactions between VH and VL. | Mildly reduced monoclonal human IgM proteins have been cleaved at cysteinyl residues to give VH fragments after S-cyanylation with 2-nitro-5-thiocyanobenzoic acid. The noncovalent interaction between the VH fragments and autologous kappa-chains was studied by ultraviolet difference spectroscopy and circular dichroism. ... |
6290011 | A review of infectious bovine rhinotracheitis, shipping fever pneumonia and viral-bacterial synergism in respiratory disease of cattle. | Unanswered questions on the etiology and prevention of shipping fever pneumonia have allowed this disease to remain one of the most costly to the North American cattle industry. Research in this area has indirected that while Pasteurella haemolytica and, to a lesser extent, P. multocida are involved in most cases, they... |
6215033 | Multiple supramolecular structures formed by interaction of actin with protamine. | When protamine is added to actin, different supramolecular structures are formed depending on the molar ratio of the two proteins and of the ionic strength of the medium. At low ionic strength, and going from a molar ratio of protamine to G-actin of 4:1, 2:1 and 1:1, globular aggregates are first converted into extende... |
6889605 | Alteration of in vivo cellulose ribbon assembly by carboxymethylcellulose and other cellulose derivatives. | In vivo cellulose ribbon assembly by the Gram-negative bacterium Acetobacter xylinum can be altered by incubation in carboxymethylcellulose (CMC), a negatively charged water-soluble cellulose derivative, and also by incubation in a variety of neutral, water-soluble cellulose derivatives. In the presence of all of these... |
6181080 | Evidence that myosin does not contribute to force production in chromosome movement. | Antibody against cytoplasmic myosin, when microinjected into actively dividing cells, provides a physiological test for the role of actin and myosin in chromosome movement. Anti-Asterias egg myosin, characterized by Mabuchi and Okuno (1977, J. Cell Biol., 74:251), completely and specifically inhibits the actin activate... |
6981649 | Immunocytochemical localization of the vitamin D-dependent calcium binding protein in chick duodenum. | The vitamin D-dependent calcium binding protein (CaBP) of chick duodenum has been localized by immunocytochemistry and by radioimmunoassay. Light microscopically, CaBP was seen to be present in the absorptive cells of the villi while in other cell types of the villi and the crypts, including goblet cells and endocrine ... |
6287425 | Transcriptional analyses of the Bacillus licheniformis penP gene. | We report the promoter structure of the Bacillus licheniformis 749/C penicillinase (penP) gene. The transcript encoding the penicillinase gene was identified by in vitro run-off transcription using both E. coli RNA polymerase and B. subtilis RNA polymerase. Utilization of this promoter in linearized DNA by the B. subti... |
7104746 | Long-term degeneration renders central tracts refractory to penetration by regenerating optic fibers. | We have examined time-dependent changes in the ability of degenerating central pathways in the goldfish to be penetrated by regenerative axons. We have found that when a tract has degenerated for 2--5 weeks it is readily penetrated by regenerating optic fibers. However, tracts which degenerated for any longer than 6 we... |
6211444 | Phosphoenzyme formation from ATP in the ATPase of sarcoplasmic reticulum. Effect of KCl or ATP and slow dissociation of ATP from precursor enzyme-ATP complex. | The ATP-dependent phosphoenzyme formation and its reversal were studied at 0 degrees C and pH 7.0 in the ATPase of sarcoplasmic reticulum. Addition of KCl or several other salts (approximately 100 mM) decreased the maximum rate of ADP-induced dephosphorylation of phosphoenzyme as well as the apparent affinity of the ph... |
6806251 | RNA polymerase of Myxococcus xanthus: purification and selective transcription in vitro with bacteriophage templates. | DNA-dependent RNA polymerase from vegetative cells of the gram-negative, fruiting bacterium Myxococcus xanthus was purified more than 300-fold by a modified Burgess procedure (Lowe et al., Biochemistry 18:1344-1352, 1979), using Polymin P precipitation, 40 to 65% saturated ammonium sulfate fractional precipitation, dou... |
6806248 | Fruiting body morphogenesis in submerged cultures of Myxococcus xanthus. | Induced by starvation, the development of fruiting bodies by Myxococcus xanthus on glass and plastic surfaces under a layer of liquid was followed microscopically. Calcium ions and a neutral pH were required for development of a Myxococcus strain that grew dispersed in liquid culture. Initially asymmetric aggregates la... |
6806237 | Phosphorylation and methylation of proteins during Myxococcus xanthus spore formation. | Post-translational modification of proteins was examined during the life cycle of Myxococcus xanthus. A specific pattern of protein phosphorylation was observed in vegetative cells. When spore formation was induced by glycerol, significant changes in the pattern of protein phosphorylation were observed, including the p... |
18963200 | Formation constant and stoichiometry of the acetonitrile:18-crown-6 complex by nuclear magnetic resonance, raman and infrared spectroscopy. | Crown ethers are increasingly used in a variety of chemical applications. While crown ether complexes with alkali-metal cations have been extensively studied, relatively little is known about their complexes with neutral molecules to form so-called host: guest complexes. The use of NMR is reported for the determination... |
7119002 | Strongylocentrotus purpuratus spindle tubulin. I. Characteristics of its polymerization and depolymerization in vitro. | Tubulin was extracted from spindles isolated from embryos of the sea urchin Strongylocentrotus purpuratus, repolymerized in vitro, and purified through three cycles of temperature-dependent assembly and disassembly. In addition to the tubulin, these preparations contain a protein of 80 kdaltons and a small but variable... |
6889599 | Ultrastructure of clots during isometric contraction. | We explored the retraction or contraction of platelet-fibrin clots under isometric conditions. In the presence of micromolar calcium clots of normal platelet-rich plasma developed tension at an initial rate of 0.1 to 0.2 g/min per cm2 (initial cross-sectional area). Electron microscopy of clots fixed after attaining a ... |
6126482 | Effects of exogenous proteins on cytoplasmic streaming in perfused Chara cells. | Cytoplasmic streaming in characean algae is thought to be generated by interaction between subcortical actin bundles and endoplasmic myosin. Most of the existing evidence supporting this hypothesis is of a structural rather than functional nature. To obtain evidence bearing on the possible function of actin and myosin ... |
6214561 | Centrifugation shearing exposes filamentous networks in cortical regions of crane-fly spermatocytes. | Spermatocytes of the crane-fly, Nephrotoma suturalis, were attached to electron microscope grids and then sheared by applying centrifugal force. Transmission electron microscopy of exposed regions of the cell cortex revealed networks containing arrays of filamentous structures. Networks were present in sheared spermato... |
6126481 | A novel 36,000-dalton actin-binding protein purified from microfilaments in Physarum plasmodia which aggregates actin filaments and blocks actin-myosin interaction. | In the plasmodia of Physarum polycephalum, which show a cyclic contraction-relaxation rhythm of the gel layer, huge aggregates of entangled actin microfilaments are formed at about the onset of the relaxation (R. Nagai, Y. Yoshimoto, and N. Kamiya. 1978. J. Cell Sci. 33:205-225). By treating the plasmodia with Triton X... |
7115311 | Kinetics of Vibrio cholerae sialidase action on gangliosidic substrates at different supramolecular-organizational levels. | G(d1a), G(d1b) and G(t1b) gangliosides were dispersed in the following membrane-mimicking systems: (a) homogeneous micelles; (b) mixed micelles with G(m1) ganglioside (which is resistant to the enzyme action), Triton X-100 or bovine serum albumin; (c) small unilamellar vesicles of egg phosphatidylcholine. The effect of... |
7115308 | Tubulin carbamoylation. Functional amino groups in microtubule assembly. | The characteristics of the carbamoylation of pig brain tubulin were examined by using the modification conditions with cyanate described previously [Mellado, Slebe + Maccioni (1980) Biochem. Int. I, 584--590]. The carbamoylation reaction resulted in an inhibition of microtubule assembly, which was dependent on the conc... |
7115306 | Interactions of tubulin and microtubule-associated proteins. Conformation and stability of the oligomeric species from glycerol-cycled microtubule protein of bovine brain. | 1. The conformation of bovine microtubule protein prepared by cycles of assembly and disassembly in the presence of glycerol has been studied by near-u.v. circular dichroism (c.d.) over a range of protein concentrations. The effects on the conformational properties of ionic strength and of a pH range from 6 to 7.5 have... |
7113670 | Membrane processes in myotonic dystrophy during in vitro aging of erythrocytes. | The present communication is devoted to investigating the possibility that in myotonic dystrophy (MyD) a decreased ATP utilization by the membrane may produce modifications in glycoprotein structure and/or in the supramolecular arrangement of some membrane proteins. The study was carried out a) by determining the membr... |
6214002 | [The combination methyl-CCNU, vincristine, 5-fluorouracil and streptozotocin in the treatment of advanced colo-rectal adenocarcinoma]. | Sixteen patients with advanced colo-rectal cancer were treated with the combination methyl-CCNU, vincristin, 5-fluorouracil and streptozotocin (MOF-Strepto). Seven cases were previously untreated. A partial remission was observed only in one patient (6%, confidence limits to 95%: 1-17%). Marked gastrointestinal and hem... |
6286511 | Synthesis of 18F-6-fluoropurine and 18F-6-fluoro-9-beta-d-ribofuranosylpurine. | Introduction of fluorine-18 into the 6-position of purines is described. 18F-6-fluoropurine and 18F-6-fluoro-9-beta-D-ribofuranosylpurine were prepared with high radiochemical yields by nucleophilic displacement of the trimethylammonio-group of purine with 18F-fluoride under mild conditions. 18F-labeling conditions suc... |
7104439 | Stellacyanin. Studies of the metal-binding site using x-ray absorption spectroscopy. | Stellacyanin is a mucoprotein of molecular weight approximately 20,000 containing one copper atom in a blue or type I site. The metal ion can exist in both the Cu(II) and Cu(I) redox states. The metal binding site in plastocyanin, another blue copper protein, contains one cysteinyl, one methionyl, and two imidazoyl res... |
6954518 | Inhibition of glucose transport in human erythrocytes by cytochalasins: A model based on diffraction studies. | On the basis of details of the three-dimensional structures of beta-D-glucose and of cytochalasins, either previously published or reported here (cytochalasin A), we propose a model to explain the observed difference in activity of cytochalasins in the inhibition of glucose transport. In our model cytochalasin B binds ... |
6954515 | Catalytic mechanism of glycogen phosphorylase: pyridoxal(5')diphospho(1)-alpha-D-glucose as a transition-state analogue. | Pyridoxal(5')diphospho(1)-alpha-D-glucose was used to reconstitute glycogen phosphorylase beta (1,4-alpha-D-glucan:orthophosphate alpha-D-glucosyltransferase, EC 2.4.1.1) from rabbit muscle, replacing the natural pyridoxal 5'-phosphate coenzyme. Incubation of the reconstituted enzyme alone resulted in the gradual cleav... |
6285005 | Accumulation of spliced avian retrovirus mRNA is inhibited in S-adenosylmethionine-depleted chicken embryo fibroblasts. | The synthesis and processing of B77 avian sarcoma virus RNA in infected chicken embryo fibroblasts was followed in the presence and absence of cycloleucine, a competitive inhibitor of the synthesis of S-adenosylmethionine and thus an inhibitor of RNA methylations. An increase in the steady-state levels of genome-length... |
7047388 | Murine monoclonal antibodies specific for virulent Treponema pallidum (Nichols). | Murine anti-Treponema pallidum (Nichols) lymphocyte hybridoma cell lines secreting monoclonal antibodies against a variety of treponemal antigens have been generated. Hybridomas isolated were of three major types: those that were directed specifically against T. pallidum antigens, those that were directed against trepo... |
6282110 | Phase II trial of methyl-CCNU, vincristine, 5-fluorouracil, and streptozotocin (MOF-Strep) in patients with disseminated pancreatic carcinoma. | A phase II trial of methyl-CCNU, 5-fluorouracil (5-Fu), vincristine, and streptozotocin (MOF-Strep) was conducted on 20 patients with pancreatic carcinoma. There were two partial remissions (10%) lasting 3 and 10 months. In addition, there were two minor responses. The predominant toxicity was gastrointestinal, althoug... |
7076621 | Characterization of proteins in flagellates and growing amebae of Naegleria fowleri. | Polypeptides of whole-cell extracts of Naegleria fowleri flagellates and growing amebae were resolved by two-dimensional polyacrylamide gel electrophoresis. Autoradiograms of the [35S]methionine-labeled polypeptides of amebae and flagellates were analyzed by two dimensional densitometry to determine whether there were ... |
16593202 | Theory of periodic structures in lipid bilayer membranes. | An approximate, new model for the structure of the periodic, undulated P(beta'), phase of phosphatidylcholine bilayers is proposed. The properties of this phase are deduced by minimizing a Landau-de Gennes expression for the bilayer free energy when this free energy contains a term favoring a spontaneous curvature of t... |
6295006 | Prospects for human monoclonal antibodies: a critical perspective. | Monoclonal antibodies have proved useful in detecting antigenic variation at single determinant sites on complex antigens, a fact which seems to have engendered a common misperception that a monoclonal antibody is necessarily a "monospecific" agent. Yet there exists considerable evidence that individual antibody molecu... |
7123957 | [Association between the glomerular basement membrane and fibronectin as revealed by affinity chromatography ]. | Though there is sufficient evidence that fibronectin is an integral extracellular matrix protein of the normal human kidney, the distribution and the interaction with structural proteins of the kidney have not been resolved. There are disagreements between investigators whether fibronectin is a component of the glomeru... |
7115290 | Synthesis and application of chemically reactive proteins by the reversible modification of protein amino groups with exo-cis-3,6-endo-epoxy-4,5-cis-epoxyhexahydrophthalic anhydride. | The reversible reaction of exo-cis-3,6-endo-epoxy-4,5-cis-epoxyhexahydrophthalic anhydride (EEHPA) with free protein amino groups is described. The free protein amino groups of lysozyme can be completely blocked through the reaction of the anhydride EEHPA. The chemically less reactive epoxy groups in EEHPA-modified lys... |
7113649 | Erythrocyte spectrofluorometric abnormalities in myotonic dystrophy during "in vitro" aging. | The possibility in Myotonic dystrophy (MyD) that a decreased ATP utilization by the membrane may produce modifications in glycoprotein structure and/or in the supramolecular arrangement of some membrane proteins was investigated in human erythrocytes: a) by determining the membrane sialic acid content and the cellular ... |
6179466 | Effect of dihydrostreptomycin on active transport in isolated bacterial membrane vesicles. | Membrane vesicles prepared from bacterial cells grown in the absence of dihydrostreptomycin but subsequently incubated in the presence of dihydrostreptomycin transported proline normally, but vesicles prepared from cells grown in media to which dihydrostreptomycin was added 30 min before harvesting had a greatly impair... |
6954461 | Structure of fibroblastic intermediate filaments: analysis of scanning transmission electron microscopy. | The structure of fibroblastic intermediate filaments from Chinese hamster ovary cells has been investigated by scanning transmission electron microscopy. Freshly extracted (native) filaments were compared with filaments reassembled in vitro from purified decamin. From digital micrographs of unstained specimens, direct ... |
7099962 | The B reversible Z transition of poly(dI-br5dC).poly(dI-br5dC). A quantitative description of the Z form dynamic structure. | The study of poly(dI-br5dC).poly(dI-br5dC) films by infrared spectroscopy shows that in low salt concentration, the conformation of this polynucleotide belongs to the B-family and in high salt concentration to the Z-family. 31P nuclear magnetic resonance and circular dichroism confirm the existence of these two forms. ... |
7096445 | Thylakoid membrane biogenesis in Chlamydomonas reinhardtii 137+. II. Cell-cycle variations in the synthesis and assembly of pigment. | Synthesis of the chlorophyll and the major carotenoid pigments and their assembly into thylakoid membrane have been studied throughout the 12-h light/12-h dark vegetative cell cycle of synchronous Chlamydomonas reinhardtii 137+ (wild-type). Pulse exposure of cells to radioactive acetate under conditions in which labeli... |
7045877 | Molecular cloning of Vibrio cholerae enterotoxin genes in Escherichia coli K-12. | Hybridization probes derived from the A and B subunit genes of the heat-labile enterotoxin (LT) of Escherichia coli were used to analyze DNA from Vibrio cholera strain 569B for cholera toxin gene sequences. Southern blot analysis indicated that the cholera toxin A and B subunit genes were each duplicated in the strain.... |
6953436 | Phase transitions in phosphatidylcholine multibilayers. | The (2)H NMR spectrum of a multilamellar dispersion of 1-myristoyl-2-[14,14,14-(2)H(3)]myristoyl-sn-glycero-3-phosphocholine with 1 mol% cholesterol in excess water has been recorded at temperatures between -15 degrees C and 36 degrees C. Motionally averaged quadrupole coupling constants nu(Q) and motionally induced as... |
6283178 | Encapsidation and expression of the herpes thymidine kinase gene in polyoma virus. | A recombinant DNA of 5,150 base pairs was prepared containing the intact early region of polyoma virus, including the viral origin of replication and the structural sequences of the herpes simplex virus type 1 thymidine kinase gene. Although no thymidine kinase activity was detected when herpes structural sequences alo... |
6283175 | Properties of a novel thymidine kinase induced by an acyclovir-resistant herpes simplex virus type 1 mutant. | The acyclovir-resistant mutant of herpes simplex virus type 1, SC16 S1, induced reduced levels of thymidine kinase activity (ca. 25% reduction) in infected cells. The activity appeared with kinetics similar to that in wild type-infected cells, and pulse-labeling experiments showed that the thymidine kinase polypeptide ... |
7068596 | Tubulin polymerization in dimethyl sulfoxide. | The self-assembly of tubulin devoid of microtubule-associated proteins (MAPs) has been studied using a MES buffer containing dimethyl sulfoxide (Me2SO). Between 6% and 12% v/v Me2SO, the tubulin forms polymers which resemble microtubules in their morphology and chemical properties. These Me2SO microtubules, like normal... |
7068537 | A comparative structural analysis of the flagellin monomers of Caulobacter crescentus indicates that these proteins are encoded by two genes. | The flagellum of Caulobacter crescentus is composed of two flagellin polypeptide monomers which are distinguished by molecular weight and are closely related by biochemical and immunological criteria (C. Lagenaur and N. Agabian, J. Bacteriol. 132:731-733, 1977). The synthesis and assembly of these two flagellin protein... |
7068536 | Isolation and characterization of cytoplasmic membranes and chlorosomes from the green bacterium Chloroflexus aurantiacus. | A method was developed which allows the isolation and purification of cytoplasmic membranes and chlorosomes from cells of Chloroflexus aurantiacus grown under different light conditions. The dipolar ionic detergent Deriphat (0.08%) and a sodium iodide gradient centrifugation were used in isolating cytoplasmic membranes... |
6279569 | Outer membrane protein P of Pseudomonas aeruginosa: regulation by phosphate deficiency and formation of small anion-specific channels in lipid bilayer membranes. | A new major outer membrane protein, P, was induced in Pseudomonas aeruginosa PAO1 upon growth in medium containing 0.2 mM or less inorganic phosphate. Studies with media containing different levels of phosphate and with mutants of PAO1 suggested that protein P was coregulated with alkaline phosphatase and phospholipase... |
21286100 | The practical application of exercise training principles in family medicine. | As millions of Canadians take the message of Participaction to heart, family physicians are asked a multitude of questions about exercise. It can be viewed as a pharmacological agent: dosage, frequency, host response, side effects and sensitivities should be considered in the design of an exercise program. Complication... |
7136788 | Inactivation of the potassium transport system of myelinated nerve in the presence of a cyclic ionophore. | A potassium carrying ionophore dicyclohexano-18-crown-6 was found to affect the specific ionic currents in the node of Ranvier. Its presence caused an inactivation of the potassium permeability mechanism and a decrease of the sodium permeability. The rate of inactivation of the potassium permeability depended on crown ... |
6284727 | Purification of cardiac sarcolemmal vesicles: high sodium pump content and ATP-dependent, calmodulin-activated calcium uptake. | Highly purified vesicles of cardiac sarcolemma were prepared from a homogenate of canine ventricular muscle by density gradient centrifugation. The preparation showed an extremely high content of (Na+,K+)-ATPase. The steady state levels of Na+-dependent phosphoenzyme formation in the presence of Triton X-100 and the sp... |
6807343 | Acquisition of native conformation of ribosomal 5S ribonucleic acid from Escherichia coli. Hydrodynamic and spectroscopic studies on the unfolding and refolding of ribonucleic acid. | In a continuing effort to decipher the molecular mechanism of ribosome self-assembly [e.g., Dunn, J. M., & Wong, K.-P. (1979) Biochemistry 18, 4380-4385], the mechanism of folding of 5S RNA was investigated by unfolding and refolding studies using several physical techniques including circular dichroism (CD), UV absorp... |
6283528 | A salt bridge stabilizes the helix formed by isolated C-peptide of RNase A. | C-peptide, which contains the 13 NH2-terminal residues of RNase A, shows partial helix formation in water at low temperature (1 degree C, pH 5, 0.1 M NaCl), as judged by CD spectra; the helix is formed intramolecularly [Brown, J. E. & Klee, W. A. (1971) Biochemistry 10, 470-476]. We find that helix stability depends st... |
6177867 | Surface antigenic determinants of mammalian "hepadnaviruses" defined by group- and class-specific monoclonal antibodies. | The hepatitis B-like viruses (human hepatitis B virus, woodchuck hepatitis virus, ground squirrel hepatitis virus, and duck hepatitis B virus) are hepatotropic DNA viruses which have been referred to collectively as "hepadnaviruses." Using a murine monoclonal antibody (101-2) to the surface antigen of woodchuck hepatit... |
6176672 | Biochemical studies of mammalian oogenesis: possible existence of a ribosomal and poly(A)-containing RNA-protein supramolecular complex in mouse oocytes. | Mouse follicles were labeled with [3H]uridine and then cultured in vitro for 3 days. When oocytes were disrupted, about 40% of the total radiolabeled RNA could be sedimented at 9,000g. Fractionation of this RNA on poly(U)-Sepharose revealed that about 30% and 60% of the total amount of radiolabeled poly(A)- and poly(A)... |
6281309 | Effect of parathyroid hormone on osmotic fragility of human erythrocytes. | The survival of erythrocytes (RBC) is shortened in uremia, and it has been shown that calcium influx into RBC evoked crenation and increased their rigidity. The high blood levels of parathyroid hormone (PTH) may augment entry of calcium into RBC and hence affect their integrity. We examined the effect of PTH on osmotic... |
7042034 | An electron microscopic study on VIP-like immunoreactive nerve fibers in the celiac ganglion of guinea pigs. | An immuno-electron microscopic study revealed that VIP-like immunoreactive nerve fibers in the celiac ganglion of guinea pigs were characterized by a conspicuously numerous large granular vesicles mixed with small clear vesicles. The immunoreactive materials were localized in the core of the large granular vesicles and... |
6176192 | Frequency of occurrence, mode of development, and significance or rice bodies in rheumatoid joints. | The incidence of rice bodies (RB) in synovial effusions has been studied in 36 patients with rheumatoid arthritis (RA) and in 12 patients with seronegative inflammatory arthritis (7 cases of Still's disease, 3 of psoriatic arthritis, and 2 of ankylosing spondylitis). In the RA group 50 joints were aspirated before and ... |
6125268 | The stoichiometry of the Ca2+ pump in human erythrocyte vesicles: modulation by Ca2+, Mg2+ and calmodulin. | Active Ca2+ uptake and the associated (Ca2+ + Mg2+)-ATPase activity were studied under the same conditions in an inside-out vesicle preparation of human red blood cells made essentially by the procedure of Quist and Roufogalis (Journal of Supramolecular Structure 6, 375-381, 1977). Some preparations were treated with 1... |
6284971 | Poliovirus empty capsid morphogenesis: evidence for conformational differences between self- and extract-assembled empty capsids. | In this paper we describe the use of specific proteinases, surface-specific radioiodination, and antigenic reactivity in conjunction with isoelectric focusing for probing the conformations of different polioviral empty capsid species. Naturally occurring empty capsids (called procapsids) with an isoelectric point of 6.... |
6284961 | In vitro reassembly of vesicular stomatitis virus skeletons. | Vesicular stomatitis virus (VSV) has been disrupted with nonionic detergent plus 0.5 M NaCl under conditions which result in solubilization of the viral glycoprotein (G), matrix protein (M), and lipids, leaving the nucleocapsid in a highly extended state. Dialysis of these suspensions to remove NaCl was found to result... |
6124240 | A new method for the extraction and purification of K99 pili from enterotoxigenic Escherichia coli and their characterization. | It was found that K99 pili from enterotoxigenic Escherichia coli (of bovine origin) could be extracted by treatment with 3M-KSCN solution. The K99 pili were purified by preparative isoelectric focusing to apparent homogeneity as judged by the presence of a single band on sodium dodecyl sulphate/polyacrylamide-gel elect... |
6210435 | Effect of various acceptors on the rates of the cyclization and chain-shortening of amylose catalyzed by the cyclodextrin glycosyltransferase from Klebsiella pneumoniae M 5 al. Improvement of new photometric assay methods. | The effect of various acceptors on the cyclization and chain-shortening reaction of amylose catalyzed by cyclodextrin glycosyltransferase [(1 leads to 4)-alpha-D-glucan: [(1 leads to 4)-alpha-D-glycopyranosyl]transferase (cycling) EC 2.4.1.19] from Klebsiella pneumoniae M 5 al was studied by use of photometric-assay me... |
7074190 | Identification of the scattering elements responsible for lens opacification in cold cataracts. | Using both quasi-elastic light scattering spectroscopy and angular dissymmetry in the intensity of the scattered light, we examined the onset of turbidity for intact calf lenses and for isolated nuclear cytoplasm. In the case of the nuclear cytoplasm these measurements demonstrate the presence of two kinds of scatterer... |
7070384 | [Molecular arrangement of protochlorophyll aggregated forms in solid films]. | The conditions were found for the successive self-assembly of two protochlorophyll aggregated forms in solid films with absorption maxima at 647 (+/-1) nm (PChl 647) and 651 (+/-1) nm (PChl 651) and fluorescence maxima at 653-655 nm and 654-657 nm, respectively. These forms model the native photochemically active form ... |
6121757 | Ability of Neisseria gonorrhoeae, Neisseria meningitidis, and commensal Neisseria species to obtain iron from lactoferrin. | The ability of 107 Neisseria isolates to compete for iron with human lactoferrin (LF) was examined. Each of 15 meningococci, 53% of 59 selected gonococci, and 24% of 33 commensal Neisseria could use LF-bound iron for growth. Isolates which could not obtain iron from LF were growth inhibited when sufficient LF was added... |
7040246 | Adherence of Shigella flexneri to guinea pig intestinal cells is mediated by a mucosal adhesion. | Guinea pig colonic epithelial cells released by treating sections of the colon with solutions containing EDTA, dithiothreitol, and citrate avidly adhered Shigella flexneri bacteria. Separation of the intestinal cells from nonbound bacteria was achieved by differential sedimentation on a Percoll gradient. Adherence of S... |
6800419 | Monoclonal antibodies to porcine factor VIII coagulant and their use in the isolation of active coagulant protein. | Partially purified preparations of porcine factor VIII:C were used to immunize mice and spleen cells from the immunized animals were fused to NS-1 mouse myeloma cells. The ability of hybrid culture fluids to bind factor VIII:C was detected with a radiolabelled, affinity-purified, human antihuman VIII:C inhibitor. Three... |
7059030 | Deuterated methoxyflurane anesthesia and renal function in Fischer 344 rats. | Inorganic fluoride (F-) production and renal function were assessed in six groups of Fischer 344 rats administered either methoxyflurane (MOF) or deuterated methoxyflurane (d4-MOF). One untreated and one phenobarbital (PB)-treated group were exposed for two hours to either air, 0.5 per cent (V/v) MOF, or 0.5 per cent (... |
7091834 | Concentrations of methoxyflurane and nitrous oxide in veterinary operating rooms. | The surgical rooms of 14 private veterinary practices were monitored to determined methoxyflurane (MOF) concentrations during surgical procedure under routine working conditions. The average room volume for these 14 rooms was 29 m3. The average MOF value for all rooms was 2.3 ppm, with a range of 0.7 to 7.4 ppm. Four o... |
6280162 | In vitro formation of multimeric DNA structures mediated by purified simian virus 40 chromatin. | Simian virus 40 chromatin was incubated after purification by sucrose density-gradient centrifugation with various circular double-stranded DNA substrates. Monomeric rings were converted in the presence of Mg2+ to structures possessing a higher degree of complexity. Dimeric catenanes, as well as multimeric linear struc... |
7068584 | Comparative glucan specificities of two types of spinach leaf phosphorylase. | Two types of alpha-glucan phosphorylase [EC 2.4.1.1] from spinach leaves have been separately purified to near homogeneity. Type I enzyme shows a subunit molecular weight of 92,000 and Km values for amylopectin, glycogen and amylose much smaller than that for maltopentose. Cyclodextrin is a normal competitive inhibitor... |
7062249 | Potentiometric study of molecular complexes of weak acids and bases applied to complexes of alpha-cyclodextrin with para-substituted benzoic acids. | The theory of the potentiometric methods of studying complexes of ionizable substrates was developed, nd graphical techniques are described for obtaining stability constant estimations from the data. The method described is for a system in which the conjugate acid and base forms of the substrate (S), are capable of for... |
6174532 | Assembly of keratin onto PtK1 cytoskeletons: evidence for an intermediate filament organizing center. | Purified keratin, solubilized in 8 M of urea, was added to Triton X-100-extracted PtK1 cells in 5 mM PIPES buffer. The buffer conditions induced assembly of keratin filaments which appear to associate with nuclei of extracted cells. These keratin fibers extend beyond the original margin of the cells and frequently form... |
7199529 | In situ reconstitution of myosin filaments within the myosin-extracted myofibril in cultured skeletal muscle cells. | We studied the in situ reconstitution of myosin filaments within the myosin-extracted myofibrils in cultured chick embryo skeletal muscle cells using the electron microscope and polarization microscope. Myosin was first extracted from the myofibrils in glycerinated muscle cells with a high-salt solution containing 0.6 ... |
7059798 | Pathway choice by regenerating optic fibers following tectal lobectomy in the goldfish: inferences from the study of gliosis in tectal efferent bundles. | Cell counts in various fiber bundles of the goldfish brain have demonstrated a profound, but transient gliosis of tectal (and pretectal) efferent pathways following removal of a tectal lobe. In the majority of cases, the pathways which underwent gliosis were also those which were penetrated by regenerating optic fibers... |
7059650 | On the wobbling-in-cone analysis of fluorescence anisotropy decay. | Interpretation of fluorescence anisotropy decay for the case of restricted rotational diffusion often requires a model. To investigate the extent of model dependence, two models are compared: a strict cone model, in which a fluorescent probe wobbles uniformly within a cone, and a Gaussian model, where the stationary di... |
7035432 | Kinetics of minichromosome replication in Escherichia coli B/r. | Replication control of the minichromosome pAL2 was found to differ from that of the chromosome in synchronously dividing populations of Escherichia coli B/r. Initiation of minichromosome replication took place at an increasing rate throughout synchronous growth. No coupling to initiation of chromosome replication was d... |
16593158 | Oriented properties of the chlorophylls: Electronic absorption spectroscopy of orthorhombic pyrochlorophyllide a-apomyoglobin single crystals. | The orientations of the transition dipole moments in chlorophyll (Chl) are among the most useful spectroscopic properties for determining macromolecular architecture in photosynthetic complexes; however, the relationships between these orientations and the Chl molecular geometry are unknown. In order to solve this prob... |
7188366 | Interaction of tubulin with non-denaturing amphiphiles. | Soluble purified calf brain tubulin contains extensive and easily accessible regions capable of hydrophobic interactions. The binding of non-ionic and mild anionic detergents to this protein has been characterized by difference absorption spectroscopy and equilibrium gel chromatography with labelled ligands. Tubulin bo... |
7188359 | Seven mammalian aminoacyl-tRNA synthetases co-purified as high molecular weight entities are associated within the same complex. | Seven aminoacyl-tRNA synthetases from sheep liver were co-purified as high mol. wt. entities to constant specific activities. The purified multienzyme preparation displayed an apparent mol. wt. of approximately 10(6) and was composed of 11 distinct polypeptides, as revealed by SDS-polyacrylamide gel electrophoresis (SD... |
6220653 | Ca2+/calmodulin-dependent phospholamban kinase from cardiac sarcoplasmic reticulum is distinct from phosphorylase kinase and forms a regulatory complex with phospholamban and the Ca2+-ATPase. | We recently reported that phospholamban, the activator of the cardiac sarcoplasmic reticulum calcium pump, is phosphorylated by both cAMP-dependent protein kinase and a membrane-bound, Ca2+/calmodulin-dependent phospholamban kinase. Phospholamban kinase and glycogen phosphorylase b kinase share the same substrate speci... |
6756644 | Dynamic aspects of the supramolecular organization of intermediate filament networks in cultured epidermal cells. | We have shown, by indirect immunofluorescence microscopy using an antiserum against the mouse keratin subunit K2 and by electron microscopy, that transformed (PAM) and primary (PME) mouse epidermal cells possess extensive networks of IF bundles. Following trypsinization and replating of PAM cells, IF bundles are seen t... |
6959073 | Neutrophil function during immunotherapy for acute myelogenous leukemia in remission. | In acute myelogenous leukemia the remission time may be prolonged by adding immunotherapy to maintenance chemotherapy. The mechanisms for this action are nuclear. We have studied polymorphonuclear neutrophil (PMN) functions in 18 patients with acute myelogenous leukemia in remission treated either with chemotherapy (CT... |
6182666 | The wrapping phenomenon in air-dried and negatively stained preparations. | We demonstrate that the interface energies involved in the direct preparation of supramolecular structures onto supporting films leads very frequently to a smooth wrapping of the supporting film around approximately one third to one half of the structure. We conclude that in such cases the structure is more rigid than ... |
7128906 | Binding of basic proteins to glycoproteins in human bronchial secretions. | 1. Secretions were aspirated from a patient with no history of pulmonary disorder. 2. Mucus glycoproteins, which exhibited blood group A activity, were separated into cetyltrimethylammonium bromide (cetavlon)- and ethanol-precipitable fractions. 3. The cetavlon-precipitable mucin was pure by analytical ultracentrifugat... |
6889607 | In vitro labeling of proteins by reductive methylation: application to proteins involved in supramolecular structures. | Actin and tropomyosin, purified from both muscle and brain, and alpha-actinin, purified from muscle, have been labeled in vitro by reductive methylation to specific activities of greater than 10(5) dpm/micrograms protein. Actin so modified bound DNase I and polymerized identically to unmodified actin. Furthermore, the ... |
6125374 | Biological substrates of anxiety: benzodiazepine receptors and endogenous ligands. | Benzodiazepines have been shown to produce most, if not all, of their pharmacological effects by directly interacting with specific recognition or receptor sites within the CNS. The presence of benzodiazepine receptors has prompted many studies as to their possible physiological significance, including attempts at isol... |
6178195 | Three-dimensional structure of proteins determined by electron microscopy. | Recent developments in specimen preparation and image processing techniques have made it possible to determine the three-dimensional structure of proteins by electron microscopy. Periodic supramolecular aggregates of the protein under investigation are requiring to minimize radiation damage and to maximize the signal-t... |
7088914 | [Structural study of Eremurus glucomannans by electron microscopic and roentgenographic methods]. | By electron microscopy and roentgenography glucomannanes from four species of Eremurus have been examined and shown to be polymorphic. Deacetylated glucomannane produces a lamellar form with a high degree of crystallinity. Partially acetylated glucomannane produces a fibrillar form representing a poorly ordered structu... |
6283114 | Interference among defective interfering particles of vesicular stomatitis virus. | Three defective interfering (DI) particles of vesicular stomatitis virus (VSV), all derived from the same parental standard San Juan strain (Indiana serotype), were used in various combinations to infect cells together with the parental virus. The replication of their RNA genomes in the presence of other competing geno... |
6283107 | Glycoprotein gE of herpes simplex virus type 1: effects of anti-gE on virion infectivity and on virus-induced fc-binding receptors. | An Fc-binding glycoprotein, designated gE, was detected previously in cells infected with herpes simplex virus type 1 (HSV-1) and in virion preparations isolated from infected cells. For the studies reported here, we purified gE from HSV-1 strain HFEM(syn) by affinity chromatography and preparative electrophoresis and ... |
7082303 | Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of medium-chain-length (C8-C12) acyl-CoA esters by goat mammary-gland fatty acid synthetase. | 1. Ruminant mammary-gland fatty acid synthetases can, in contrast with non-ruminant mammary enzymes, synthesize medium-chain fatty acids. 2. Medium-chain fatty acids are only synthesized in the presence of a fatty acid-removing system such as albumin, beta-lactoglobulin or methylated cyclodextrin. 3. The short- and med... |
6282262 | Fluid-phase interaction of C1 inhibitor (C1 Inh) and the subcomponents C1r and C1s of the first component of complement, C1. | Interactions between proenzymic or activated complement subcomponents of C1 and C1 Inh (C1 inhibitor) were analysed by sucrose-density-gradient ultracentrifugation and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The interaction of C1 Inh with dimeric C1r in the presence of EDTA resulted into two bimolec... |
7043958 | [Hypothesis of possible evolution and functional specialization based on the recombination and transposition of elementary functional blocks]. | A number of examples demonstrating that different cell and organ functions are being performed by a limited set of identical or similar functional blocks has been analysed. The latters are molecular or supramolecular structures fulfilling elementary functions. Functional evolution, functional and structural specializat... |
6979042 | In vivo immune response to a T-cell-dependent antigen by cultures of disassociated murine Peyer's patch. | The first line of defense against pathogens that enter the host by the oral route appears to involve the gut-associated lymphoreticular tissue-e.g., Peyer's patches (PP). Although animals can readily be immunized by orally administered antigen that mobilizes the secretory immune system, there is a total lack of local a... |
6952192 | Specific cellular stimulation in the primary immune response: a quantized model. | A general theory for the initial phase of T cell independent immune response is derived from elementary physical-chemical considerations and from the premise that response entails a quantized linkage of cell surface receptors. The theory leads to the construction of explicit antigen dose--response and antigen dose--sup... |
6278414 | Computer programs for nucleic acid sequence manipulation. | Computer programs are described which help during the collection and analysis of nucleic acid sequence data. They are written in FORTRAN and have been implemented on a PDP 11/60 computer. |
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