Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.25.1 (proteasome)
 28,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two enterotoxigenic strains of Staphylococcus aureus were examined for their ability to produce a number of extracellular enzymes at various water activity (alphaw) levels. Supernatant, dialyzed culture media were analyzed for total and relative levels of enzyme activity. With the exception of protease, enzyme activity was greatest in spent media obtained from cultures grown at 0.996 alphaw, the highest level tested. Enzyme activity in spent media from an enterotoxin B-producing strain was generally more sensitive to alphaw reduction than activity from an enterotoxin A-producing strain. Unlike the other enzymes assayed, acid and alkaline protease activities were greatest when the organism was grown at 0.94 alphaw.
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PMID:Influence of water activity on the production of extracellular enzymes by Staphylococcus aureus. 63 48

Corrected analysis results are handled graphically to find the most probable molar composition of polypeptides and proteins and to refine the molecular weights, even if only approximate molecular weights are available. The principle and properties of the graphical representation of idealized analyses are discussed first. Examples are given of the solution for a polypeptide consisting of 25 amino acids and for its not quite precise analysis and for a concrete protein - extracellular alkaline protease from Aspergillus flavus. The general character of the method is discussed.
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PMID:Graphical refinement of the amino acid molar ratio and of the molecular weights of peptides and proteins on the basis of amino acid analyses. 66 84

The noise performance of an experimental microchannel plate x-ray image intensifier has been evaluated. The intensifier, constructed for use with photons of energies between 20 and 150 keV, uses an MCP as the photon-to-electron converter. The influence of noise was determined by analysis of the optical-density fluctuations of a photograph of the viewing screen of the intensifier when the conversion layer was exposed to between 1 and 60 mR. Additionally, the contrast-detail performance of the experimental device was determined. The influence of both stochastic noise, due to quantum mottle and pulse-height variations, and structural noise, due to fluctuations in inherent gain from point to point, have been considered by using a model that adds these components.
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PMID:Noise characteristics of a microchannel plate x-ray image intensifier. 68 49

The sequence of the amino-terminal 349 residues of rabbit muscle glycogen phosphorylase (EC 2.4.1.1) has been determined. Limited proteolysis of native phosphorylase b (841 residues, subunit molecular weight 97 412) by subtilisin BPN', Streptomyces alkaline protease, or elastase yielded two large segments (light and heavy). The light segment isolated from the subtilisin digest was cleaved at methionyl bonds with cyanogen bromide to yield eight major fragments and two minor overlapping fragments. The alignment of the major fragments was obtained by analysis of the two minor fragments, of five tryptic peptides containing methionine and of one large fragment generated by cleavage of an aspartylproline bond. Analysis of two cyanogen bromide fragments (CB14 and CB17) isolated from the intact molecule identified the sites susceptible to limited proteolysis and the overlap between the light and the heavy segments. Serine-14 and tyrosine-155 were identified as the residues involved in the covalent and allosteric controls of the enzyme, respectively. Residues 108 and 142 were identified as the cysteine residues reported to be involved in the aggregation of subunits.
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PMID:Sequence of the amino-terminal 349 residues of rabbit muscle glycogen phosphorylase including the sites of covalent and allosteric control. 72 24

The exudates or liquid droplets on various structures of a number of fungi were examined. The droplets were enveloped in membranous material and were associated with actively growing mycelia, including fruiting structures. Osmium tetroxide vapour-fixed droplets of Claviceps purpurea, Myrothecium roridum, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Thanathephorus cucumeris did not dry to a powder but remained intact as spheres when freeze-dried. Fractured spheres, examined with the scanning electron microscope, showed the presence of a membranous structure similar to that of rapidly frozen colloidal solutions with the ice crystals removed by sublimation. Locules or cavities within the freeze-dried droplets are thought to be due to the entrapment of air when droplets coalesce. Biochemical analyses of the exudates showed that acid phosphatase, beta-glucosidase, acid and alkaline protease. RNase polygalacturonase and cellulase enzymes as well as oxalic acid and ammonia were present.
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PMID:Fungal exudates. 72 49

The fine purification of an alkaline protease (thermitase) from Thermoactinomyces vulgaris by means of isoelectrical focussing in the flat-bed procedure using granulated gel is reported. An Na2SO4-precipitated crude product serves as the starting material. Isoelectrical focussing leads in a single step to a highly purified protein with an uniform N-terminal end group. The enzyme has an IP at 9.0 and a mol. wt. of 37,400; it consists of a polypeptide chain with arginine as the N-terminal, and tyrosine as the C-terminal end group. In addition to an essential serine residue, a SH group could be demonstrated which is hardly accessible in the native enzyme. Furthermore, the influence of different protease inhibitors was studied.
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PMID:[Characterization of a protease from Thermoactinomyces vulgaris (thermitase). 2. Single-step fine purification and protein-chemical characterization]. 74 56

The effect of different sources of carbon, nitrogen, amino acids and vitamins on the synthesis of alkaline proteases by the stock and mutant strains of Bacillus mesentericus and by the natural strain of Bacillus subtilis-12 has been investigated. The maximum synthesis of alkaline protease has been obtained in the media containing starch or its hydrolysates--dextrine and maltose as the carbon source. Ammonium phosphate and casein as the nitrogen source prove to be optimal for Bac. mesentericus and Bac. subtilis, respectively. Complex B vitamins added to the nutrient medium accelerate the enzyme synthesis 2.5-4-fold.
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PMID:[Effect of carbon and nitrogen sources and complex B vitamins on the synthesis of alkaline protease by different strains of Bacillus mesentericus and Bacillus subtilis]. 81 99

The influence of culture medium composition on alkaline protease production was studies. Various carbon sources such as glycerol, glucose, lactose and starch were tested. Different concentrations of lactose and bactopeptone have been tested. The optimum medium composition was found to be: (g/l) lactose 20.0; bactopeptne Difco 10.0; NaCl 1.5;mgSO47.H20 0.15; CaCl2 0.06; K2HPO4 1.5; KH2PO4 1.5; Na2SO4 1.5; MnCL2.4H2O 0.01. A cell concentration of c.a 9.5 g/l has been obtained after 30 hours. The maximun alkaline protease production (5,000 uAPAM/ml) was attained after 60 hours. The trials were carried on rotary shaker in 1 liter erlenmeyer flasks containing 250 ml of medium.
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PMID:[Alkaline protease production]. 81 79

The effect of glucose and amino acids on the synthesis of alkaline protease of the prototroph strain and auxotrophs of Bacillus subtilis A-50 was studied. There are both general and different from one another mechanisms of regulation for sporulation and protease synthesis as one of early stages of sporulation. Most auxotroph mutations pleiotropically decrease the level of protease synthesis and the efficiency of sporulation. At the same time the differences depending on sporulation and protease formation from glucose, amino acids and caseinoacids are observed. The increase in glucose concentration in the medium from 0.5 to 5% leads to intensification of protease synthesis and decrease of the sporulation efficiency. The suppression of alkaline protease formation in B. subtilis occurs when amino acid concentration is of the order of 1.5 mg/ml in the studied combination in the presence of 1--5% glucose. The strongest inhibitory effect was discovered for 2d, 3d and 4th amino acid groups in the presence of 5% glucose, whereas amino acids of the first group stimulate the protease synthesis in the presence of 2% glucose. The stimulatory effect of amino acids of the first groups is due to histidine and arginine.
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PMID:[Regulation of alkaline protease synthesis in Bacillus subtilis A-50]. 81 33

The effect of proteolytic enzymes on sexual agglutinability of haploid cells of the yeast Saccharomyces cerevisiae was examined. Sexual agglutinability of cells of both a and alpha types was lost on treatment with alkaline protease and two kinds of neutral proteases of Bacillus subtilis, pronase and alpha-chymotrypsin. Agglutinability of alpha type cells was lost after treatment with acid protease of Rhizopus chinensis and trypsin, but that of a type cells was not. These results indicate that the sex-specific substance responsible for the sexual agglutination (agglutination factor) in a type cells differ from that in alpha type cells. Agglutination factors were solubilized from cell-wall fractions of both mating types by Glusalase treatment. These crude factors specifically inhibited the agglutinability of cells of the opposite mating type with little effect on the agglutinability of cells of the same mating type.
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PMID:Mating reaction in Saccharomyces cerevisiae. VII. Effect of proteolytic enzymes on sexual agglutinability and isolation of crude sex-specific substances responsible for sexual agglutination. 81 52


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