Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lymph node viable cells suspension of immunized mice was centrifugated. The supernatant was chromatographed in Sephadex G-200, and fractions were deproteinized. The deproteinized third fraction (Mol wt 30000) stimulated specifically the plaque-forming cells of intact mice immunized by SRBC. It restored the capacity to antibody production in the lethally irradiated intact mice protected by the syngeneic bone marrow. The activity of this fraction disappeared following treatment with RNA-ase, but not with DNA-ase or trypsin. The first and the second deproteinized fractions of the supernatant inhibited non-specifically the viable lymph node cells of the immunized animals in the intact mice immunized with SRBC.
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PMID:[Replacement of the helper function of T cells by an RNA-containing antigen-specific lysis factor]. 31 Dec 27

To collect information on synthesis and regulation of the peptidoglycan-associated pore-forming outer membrane proteins b and c, mutants resistant to phages Me1 and TuIa were analyzed. Genetic analysis showed three linkage groups, corresponding with the genes tolF (phenotype b-c+), meoA (phenotype b+c-) and ompB (phenotypes b-c-, b-c+, b++c- and b++c+/-). It has recently been described that also a b+c- phenotype can occur in the latter linkage group [Chai, T., Foulds, J., J. Bacteriol. 130, 781-786 (1977)]. Among ompB (b-c+)/meoA (b+c-) double mutants strains were found with the b+c- phenotype, showing that ompB is not the structural gene for protein b. Studies on purified proteins b and c showed profound differences between the two proteins with respect to the electrophoretic mobility of fragments obtained by treatment with cyanogen bromide, trypsin and chymotrypsin. The amino acid in position three of the amino-termini of proteins b and c, isolated from isogenic strains, were identified as isoleucine and valine respectively. Both the genetic and biochemical results are consistent with a model recently published [Ichihara, S., Mizushima, S., J. Biochem. (Japan) 83, 1095-1100 (1978)] which predicts that tolF and meoA are the structural genes for the proteins b and c respectively and that ompB is a regulatory gene whose product regulates the levels of both proteins.
Mol Gen Genet 1979 Jan 31
PMID:Genetics and biochemistry of the peptidoglycan-associated proteins b and c of Escherichia coli K12. 37 3

The isolation and characterization of two mutants of Escherichia coli K12 with an altered outer membrane protein c is described. The first mutant, strain CE1151, was isolated as a bacteriophage Me1 resistant strain which contains normal levels of protein c. Mutant cells adsorbed the phage with a strongly decreased rate. Complexes of purified nonheat modified wild type protein c and wild type lipopolysaccharide inactivated phage Me1, indicating that these components are required for receptor activity for phage Me1. When wild type protein c was replaced by protein c of strain CE1151, the receptor-complex was far less active, showing that protein c of strain CE1151 is altered. The second mutant produces a protein c with a decreased electrophoretic mobility, designated as protein c. An altered apparent molecular weight was also observed for one or more fragments obtained after fragmentation of the mutant protein with cyanogen bromide, trypsin and chymotrypsin. Alteration of protein c was not accompanied by a detectable alteration in protein b or its fragments. Both mutations are located at minute 48 of the Escherichia coli K12 linkage map. The results strongly suggest that meoA is the structural gene for protein c.
Mol Gen Genet 1979 Jan 31
PMID:meoA is the structural gene for outer membrane protein c of Escherichia coli K12. 37 4

A mutant of a derivative of the colicin E1 plasmid has been isolated that does not confer immunity to colicin E1 on its host (imm-) although it is still capable of producing colicin (col+). Cells carrying the col+, imm- plasmid are capable of forming colonies and grow best in liquid culture in the presence of trypsin. The induction of colicin synthesis by ultraviolet light has been analysed using this mutant plasmid. The results suggest that a) the expression of the col+ gene may be delayed for many generations after the inducing stimulus, b) although induced cells are usually killed they can reproduce and c) the capacity to produce colicin can be propagated and segregated into the progeny of an induced cell.
Mol Gen Genet 1979 Jun 20
PMID:Studies of colicin induction with an imm- col+ mutant of the plasmid colicin E1. 38 54

The three-dimensional crystal structure of bovine trypsinogen at approximately pH 7.5 was initially solved at 2.6 A resolution using the multiple isomorphous replacement method. Preliminary refinement cycles of the atomic coordinates trypsinogen have been carried out first to a resolution of 2.1 A, and later to 1.9 A, using constrained difference Fourier refinement; During the process, structure factors Fc and phi c were calculated from the trypsinogen structure and final interpretation was based on an electron-density map computed with terms (2 Fo - Fc) and phases phic at a resolution of 1.9 A. Crystals of trypsinogen grown from ethanol-water mixtures are trigonal with space group P3121, and cell dimension a = 55.17 A and c = 109.25 A. The structure is compared with the bovine diisopropylphosphoryltrypsin structure at approximately pH 7.2, oirginally determined from orthohombic crystals by Stroud et al. (Stroud, R.M., Kay L.M., and Dickerson, R.E. (1971), Cold Spring Harbor Symp. Quant. Biol. 36, 125-140; Stroud, R.M., Kay, L.M., and Dickerson, R.E. (1974), J. Mol. Biol. 83, 185-208), and later refined at 1.5 A resolution by Chambers and Stroud (Chambers, J.L., and Stroud, R.M. (1976), Acta Crystallogr. (in press)). At lower pH, 4.0-5.5 diogen, with cell dimensions a = 55.05 A and c = 109.45 A. This finding was used in the solution of the six trypsinogen heavy-atom derivatives prior to isomorphous phase analysis, and as a further basis of comparison between trypsinogen and the low pH trypsin structure. There are small differences between the two diisopropylphosphoryltrypsin structures. Bovine trypsinogen has a large and accessible cavity at the site where the native enzyme binds specific side chains of a substrate. The conformation and stability of the binding site differ from that found in trypsin at approximately pH 7.5, and from that in the low pH form of diisopropylphosphoryltrypsin. The catalytic site containing Asp-102, His-57, and Ser-195 is similar to that found in trypsin and contains a similar hydrogen-bounded network. The carboxyl group of Asp-194, which is salt bridged to the amino terminal of Ile-16 in native trypsin or other serine proteases, is apparently hydrogen bonded to internal solvent molecules in a loosely organized part of the zymogen structure. The unusually charged N-terminal hexapeptide of trypsinogen, whose removal leads to activation of the zymogen, lies on the outside surface of the molecule. There are significant structural changes which accompany activation in neighboring regions, which include residues 142-152, 215-550, 188A-195. The NH group of Gly-193, normally involved in stabilization of reaction intermediates (Steitz, T.A., Henderson, R., and Blow, D.M. (1969), J. Mol. Biol. 46, 337-348; Henderson, R. (1970), J. Mol. Biol. 54, 341-354; robertus, J.D., Kraut, J., Alden, R.A., and Birkoft, J.J. (1972), Biochemistry 11, 4293-4303) in the enzyme, is moved 1.9 A away from its position in trypsin...
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PMID:Structure of bovine trypsinogen at 1.9 A resolution. 55 51

The redistribution of surface-bound polycations on human lymphocytes and mouse-spleen lymphocytes was studied by fluorescence microscopy. A redistribution pattern after incubation with protamine, polylysine and DEAE-dextran resembling patching and capping processes was observed both at 20 degrees C and at 4 degrees C. The interaction between polycations and the cell surface is considered to represent non-specific binding to the membrane proteins. The redistribution process is regarded as precipitaion processes. This is in accordance with the finding that no effect on the binding and redistribution of polycations was noticed in the presence of NaN3, vinblastine sulphate, vincristine sulphate, colchichine, cytochalasin B or trypsin treatment. When incubation periods longer than 5 min. were employed beginning internalization of flourescent material is observed. Interaction with the nuclear membrane similarly resulted in rearrangements and capping.
Mol Cell Biochem 1977 Apr 12
PMID:Redistribution of polycations bound to lymphocytes. 56 1

Partially purified flounder muscle (Pseudopleuronectus americanus) glyceraldehyde 3-phosphate dehydrogenase was immobilized on cyanogen bromide-activated Sepharose. The catalytic properties of the immobilized preparation were studied to determine if immobilization alters the kinetic properties of the native holoenzyme. The results indicate that the pH activity profile of immobilized glyceraldehyde 3-phosphate dehydrogenase did not differ from that of the native enzyme. The Michaelis constants (Km) for NAD and glyceraldehyde 3-phosphate were somewhat altered. The enzyme stability toward various inactivation treatments in the presence and absence of NAD was characterized and compared to that of he native enzyme. When either form of the enzyme was incubated with urea at concentrations greater than 2M, inactivation occurred very rapidly. Incubation in 0.1% trypsin for 60 minutes decreased the activity of immobilized glyceraldehyde 3-phosphate dehydrogenase by 45% and of the native soluble enzyme by 70%. The immobilized enzyme also exhibited considerably more stability than the native soluble enzyme when exposed to a temperature of 50 degrees or to 20 mM ATP. In all cases NAD either greatly reduced the rate of inactivation or completely protected the enzyme from inactivation.
Mol Cell Biochem 1978 Nov 16
PMID:Immobilized flounder muscle glyceraldehyde 3-phosphate dehydrogenase. 56 63

After polyadenylation in vitro of the influenza virus RNA segment which contains the coding information for the matrix protein, a cDNA copy can be made using the primer p(dT)8-dA and reverse transcriptase. The sequence of 166 nucleotides of the cDNA was determined by a modification [Brownlee, G. G. & Cartwright, E. M. (1977) J. Mol. Biol, 114, 93--117] of the plus/minus method [Sanger, F. & Coulson, A. R. (1975) J. Mol. Biol. 94, 441--481] and adaptation of the "dideoxy" method [Sanger, F., Nicklen, S. & Coulson, A. R. (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 5463--5467] for sequencing DNA. The cDNA sequences is of the same sense as the mRNA for matrix protein and contains a potential initiating codon, d(ATG), at position 26--28. When matrix protein purified from virus particles was digested with chymotrypsin or trypsin and the amino acid compositions of separated peptides determined, one peptide containing nine amino acids found which had a composition corresponding to that predicted by the cDNA sequence following the first methionine codon, confirming that protein synthesis initiates at this position. The compositions of four other peptides matches those predicted from the nucleotide sequence. There is no processing of the N terminus of the protein before incorporation into the virus particle except for removal of the N-terminal methionine and addition of a "blocking" group on the resulting N-terminal serine residue.
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PMID:Nucleotide sequence coding for the N-terminal region of the matrix protein influenza virus. 57 97

The interaction of tamoxifen (ICI 46,474), a synthetic antiestrogen, with uterine cytosol proteins of immature calf and rat has been studied directly using the tritiated compound labeled with a high specific activity. The binding complexes were measured by the dextrancoated charcoal, protamine sulfate and hydroxyapatite assays. Scatchard plots revealed a single class of high-affinity (KD congruent to 1.7 nM) binding sites, with a binding capacity similar to that of estradiol. Competitive experiments showed the same binding specificity for estrogens and antiestrogens. Sucrose gradient analysis revealed an 8S binding protein which could be partially proteolysed by trypsin into a 4S binding protein. Kinetic studies showed that the association rate of tamoxifen was 5 times lower than that of estradiol and reacted according to a second order kinetics. The first-order kinetics of dissociation was considerably higher than that of estradiol, giving a half-dissociation time of 20--40 min at 0--2 degrees C. In some cases tamoxifen displayed two slopes of dissociation, but the proportion of the slow-dissociating complex was always inferior to that found with estradiol. In contrast to estradiol, the kinetic constants ratio (k-/k+) gave a calculated dissociation constant, similar to that determined in equilibrium conditions (KD), agreeing with a simple reactional scheme. We conclude that the antiestrogen tamoxifen binds directly to the 8S cytosol receptor for estrogens and not to another receptor for the antagonists. In contrast to estradiol, the antagonist is rapidly dissociated from the receptor sites and is unable to protect them against thermal inactivation. The affinity of tamoxifen for its receptor sites as determined directly is surprisingly high when compared to its affinity evaluated indirectly by competitive experiments. It is then suggested that the two ligands either bind on two different sites of the same protein or induce a different conformational change of the same binding site.
Mol Cell Endocrinol
PMID:High-affinity binding of the antiestrogen [3H]tamoxifen to the 8S estradiol receptor. 68 Mar 40

Kinetic aspects of enzymatic reactions proceeding in the autocatalytic mode are considered. Kinetic analysis of a mechanism with proenzyme-enzyme interaction and of mechanism in which activation involves an interaction with the product of enzymatic reaction is presented. It is shown that these mechanisms are distinguished by the dependences of kinetics of the process on enzyme and substrate concentrations. Method is developed for the determination of concentration of active centers of enzyme in the case of activation by reaction product. Conclusions obtained are illustrated using autocatalytic enzymatic systems such as trypsin-trypsinogen and bacterial hydrogenases-hydrogen-4,4'-dimethylbipyridinium.
Mol Biol (Mosk)
PMID:[Autocatalytic enzyme reactions]. 75 85


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