Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Relative biological values (BV) of 36 feed phosphates were determined with female turkeys in bioassays of 21-day duration using three response criteria: weight gain, tibia ash percentage, and gain:feed ratio. Calcium phosphate, dibasic dihydrate (United States Pharmacopeia) was the reference standard. Nine mono-dicalcium phosphates (M-DCP, 21.0% phosphorus), 13 di-monocalcium phosphates (D-MCP, 18.5% phosphorus), and 14 defluorinated phosphates (DFP, 18.0% phosphorus) were evaluated. The average relative BV for M-DCP, D-MCP, and DFP samples were 97.6, 94.6, and 90.8%, respectively. Solubility of phosphates was determined by four recognized methods. The solvents were water, .4% HCl, 2.0% citric acid (CA), and neutral ammonium citrate (NAC). Water solubility of M-DCP samples was greater (67.5%) than that of D-MCP (38.8%) and DFP (8.9%) samples. Correlation of water solubility of phosphates to their relative BV was quite low, and water solubility was a poor indicator of BV. When .4% HCl was the solvent, correlation coefficients (r) were .55, .33, and .72 for M-DCP, D-MCP, and DFP, respectively. Based on these results and prediction equations, .4% HCl solubility would be inappropriate for estimating BV of M-DCP and D-MCP samples. Solubility of feed phosphates (mainly D-MCP and DFP) in 2.0% CA or NAC was positively correlated with BV; the r values were .87 to .95. Both of these solubility tests provided a good index of BV. However, it would seem inappropriate and risky to replace bioassays totally with these tests. Feed phosphate users could perform either the 2.0% CA or NAC solubility test easily as a screen for BV along with other quality control procedures (i.e., phosphorus, calcium, sodium, and fluoride determinations).
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PMID:Correlation of biological value of feed phosphates with their solubility in water, dilute hydrogen chloride, dilute citric acid, and neutral ammonium citrate. 147 May 90

Two forms of a neutral protease that catalyzed the hydrolysis of succinyl-Leu-Leu-Val-Tyr-MCA were isolated from porcine skeletal muscle cytosol by fractionation on DEAE-cellulose, hydroxyapatite and Sephadex G-100. The native enzyme had a molecular mass of above 1000 kDa. Peak A, which was eluted from hydroxyapatite at 50 mM phosphate, was activated 37-fold by the detergent, SDS, while peak B which was eluted at 150 mM phosphate, was activated only 2-fold. After dialysis against water, the B form showed restored ability to be activated by SDS (9.6-fold with 0.04% SDS). The activated peak B was extremely sensitive to divalent and monovalent cations such as Ca2+, Mg2+, Na+, K+ and NH+4 as well as protease inhibitors such as leupeptin, chymostatin and DFP. These results suggest that these proteases are generally latent in the cells and may be regulated by changes in the concentrations of cations in the cytosol. We call this new type of protease, ingensin.
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PMID:Isolation of two forms of the high-molecular-mass serine protease, ingensin, from porcine skeletal muscle. 389 52

The chromatin fraction of rat liver exhibited proteolytic activity caused by serine proteases, with maximal activity at pH 8 or 10. They were analyzed by affinity labeling with [3H]diisopropylfluorophosphate followed by SDS-polyacrylamide gel electrophoresis, and partially purified by gel filtration through Sepharose 6B after selective extraction from the chromatin fraction. The following results were obtained. 1. The chromatin fraction contained three DFP-binding proteins with molecular weights of 52,000, 25,000, and 15,000 daltons, and they were tentatively designated proteins A, B, and C, respectively. Unlike proteins A and B, protein C reacted with DFP more strongly at pH 10 than at pH 8. A greater part of protein B was present in the nucleoli, while the others were predominantly distributed in extra-nucleolar chromatin. 2. Proteins A and B were extracted from the chromatin fraction by 5 M urea and 0.7 M NaCl, respectively; while protein C was not extractable by either solution. Proteins A and B were further purified by gel filtration through Sepharose 6B. 3. Protein B was a neutral protease with a maximal activity for 3H-labeled ribosomal proteins at pH 8 and showed high specificity for basic proteins, such as histone and ribosomal proteins. Protein A was an alkaline protease with a maximal activity at pH 10 and showed proteolytic activity not only for basic proteins but also for hydrophobic proteins, such as casein and non-histone proteins of chromatin. 4. Protein A was activated at pH 8 by high concentrations of NaCl, suggesting the presence of some inhibitor(s). Protein A was converted to protein C at pH 10, and also at pH 8 with high concentrations of NaCl. Thus, protein A is suggested to be the complex of protein C and unknown inhibitor(s). 5. When the chromatin fraction was incubated at pH 10, non-histone proteins were degraded much faster than at pH 8, although H1 histone was degraded at similar rates at both pHs. These results indicate that the chromatin fraction of rat liver contains at least two kinds of serine proteases, B and C, and that protease B is probably involved in the metabolism of basic protein, especially H1 histone. Protease C, the greater part of which associates with some inhibitors to form protein A, may play its main role in the metabolism of non-histone proteins.
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PMID:Studies on the serine proteases associated with rat liver chromatin. 675

Six basic proteins of 26 to 38 kDa with isoelectric points (pI) > or = 8.5 were abundant in proteins separated by two-dimensional SDS-PAGE from adult rat peritoneal mast cells (MC). One was identified previously as rat mast cell proteinase (RMCP) 1, a chymase of 26 to 28 kDa, pI > 9.0. Microsequence analyses showed that two polypeptides of about 29 and 30 kDa had NH2 terminal amino acid sequences homologous to mouse MC proteinase 5 (MCP-5), whereas the amino terminals of the 33, 35, and 36 kDa proteins were homologous to MC carboxypeptidase A (MC-CPA). Rabbit Abs produced against synthetic peptides of the identified NH2 terminal sequences were used in immunoblot studies. At least three proteins reacted with Abs to MC-CPA, whereas Abs to MCP-5 detected three adjacent polypeptides, rather than just the two identified by using microsequence analysis. Removal of oligosaccharide side chains using peptide:N-glycosidase F reduced the heterogeneity of each set of three polypeptides (MCP-5 and MC-CPA) to a band of each protein of a lower M(r). The serine proteinase inhibitor [3H]diisopropylfluorophosphate ([3H]DFP) bound to a proteinase of 30 to 35 kDa, which is probably MC tryptase (pI < or = 6.0). Immunoblot analysis of proteins from intestinal mucosal mast cells showed RMCP-2, but not RMCP-1, MCP-5, or MC-CPA. This is the first report of MCP-5 in the rat and of clearly distinguishable glycosylated forms of MC CPA. These proteinases appear to be restricted in their distribution to selected MC populations, but little is known about their functions.
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PMID:Proteinases of rat mast cells. Peritoneal but not intestinal mucosal mast cells express mast cell proteinase 5 and carboxypeptidase A. 759 1

Thermostable alkaline protease from an alkaliphilic thermophile Bacillus sp. B18' was purified by using DEAE- and CM-Toyopearl 650M column chromatographies. Molecular weights of the enzyme determined by SDS-PAGE and gel filtration were 30,000 and 28,000, respectively. The optimum pH and temperature toward the hydrolysis of casein were pH 12-13 and 85 degrees C, both of which are higher than those of a mesophilic alkaline protease from an alkaliphile, Bacillus sp. B21-2. The enzyme was stable at pH 5.0-12.0 and about 60% of the initial enzymatic activity was retained after a 60 min incubation period at pH 10.0 and 70 degrees C. Thermostability of the enzyme was enhanced by Ca2+. The enzyme activity was inhibited by DFP, suggesting that the enzyme is a serine protease. The NH2-terminal amino acid is Gln, which is that of many subtilisin-type proteases. The 20 residues of the NH2-terminal amino acid sequence have a comparative high homology with those of other alkaline proteases from alkaliphiles (40-50%), especially thermostable alkaline protease from Bacillus sp. No. AH-101 (95%) and Thermoactinomyces sp. HS682 (95%).
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PMID:Purification and properties of the highly thermostable alkaline protease from an alkaliphilic and thermophilic Bacillus sp. 776 36

Two high molecular mass proteinases, multicatalytic proteinase (MCP) and a new high molecular mass proteinase (HMP) with only chymotrypsin-like activity (Khan et al. (1994) J. Biol. Chem. 269, 10016-10021) from human erythrocyte membranes, have been compared. For this purpose, MCP was purified from human erythrocyte membranes in the active form towards synthetic peptide substrates; it also hydrolysed the protein substrates [14]methyl casein and [14C]oxidised insulin beta chain at 37 degrees C. MCP from plasma membranes exhibited hollow cylindrical structures also typical of cytosolic forms. Radiolabelled diisopropyl fluorophosphate, [3H]DFP, a serine proteinase inhibitor, labelled a band of Mr 23 000 in membrane MCP. By contrast, no labelling was obtained with HMP. Chymotrypsin-like activity of HMP was also found to be insensitive to DFP. On the other hand, DFP inhibited chymotrypsin-like and peptidylglutamyl peptide hydrolysing activities of membrane MCP, with no effect on its trypsin-like activity. The inhibition of MCP by DFP was concentration-dependent. These studies showed that MCP and HMP represent two distinct kinds of proteinases with chymotrypsin-like activities and can be distinguished by the serine proteinase inhibitor DFP.
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PMID:Membrane-bound high molecular mass proteinases from human erythrocytes. 781 93

Thirty-six feed phosphates, including nine mono-dicalcium phosphates (M-DCP, 21% P), 13 di-monocalcium phosphates (D-MCP, 18.5% P), and 14 thermochemically produced defluorinated phosphates (DFP, 18.0% P), were analyzed for moisture, Ca, P, and 9 essential minerals (K, Mg, Na, Cl, Fe, Cu, Mn, Se, and Zn). Also, nine potentially toxic elements (Al, F, As, Cd, Cr, Hg, Pb, Ni, and V) were determined. All of the M-DCP were of domestic origin; 5 of the 13 D-MCP samples were obtained in Algeria, Peru, Holland, and South Africa. The DFP samples included 10 domestic products, 2 samples from Russia, 1 from Poland, and 1 from Japan. Levels of Na were high in the DFP samples (3.96 to 5.78%), except for the two Russian samples, which contained only .16 and .19%. Magnesium levels varied from .09 to .76%, .02 to 1.21%, and .01 to 1.54% in the M-DCP, D-MCP, and DFP samples, respectively. Two Russian DFP samples contained 1.51 and 1.54% Mg. Chlorine levels were generally quite low (.002 to .020%); however, two precipitated D-MCP samples contained .12 and 1.47% Cl. Iron levels were high (.24 to 1.41%) in all samples except the bone-precipitated D-MCP (.039%), and the reference standard, calcium phosphate, dibasic dihydrate, USP (.029%). Levels of Cu, Mn, and Zn were quite variable. Cadmium varied from < 1 ppm in the DFP samples to 67 ppm in one experimental M-DCP. Vanadium levels varied from 20 to 796 ppm in one experimental M-DCP sample. Fluorine levels were in the acceptable range, .05 to .21%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Levels of various elements of concern in feed phosphates of domestic and foreign origin. 820 31

An alkaline protease was isolated from culture filtrate of B. subtilis NCIM 2713 by ammonium sulphate precipitation and was purified by gel filtration. With casein as a substrate, the proteolytic activity of the purified protease was found to be optimal at pH 8.0 and temperature 70 degrees C. The purified protease had molecular weight 20 kDa, Isoelectric point 5.2 and km 2.5 mg ml(-1). The enzyme was stable over the pH range 6.5-9.0 at 37 degrees C for 3 hr. During chromatographic separation this protease was found to be susceptible to autolytic degradation in the absence of Ca2+. Ca2+ was not only required for the enzyme activity but also for the stability of the enzyme above 50 degrees C. About 62% activity was retained after 60 min at pH 8.0 and 55 degrees C. DFP and PMSF completely inhibited the activity of this enzyme, while in the presence of EDTA only 33% activity remained. However, it was not affected either by sulfhydryl reagent, or by divalent metal cations, except SDS and Hg2+. The results indicated that this is a serine protease.
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PMID:A study of extracellular alkaline protease from Bacillus subtilis NCIM 2713. 1256 22

In a 5L fermentor the production conditions of alkaline protease gene engineering strain BA071 were investigated. The maximum activity of alkaline protease reached 24,480 u/mL in 40 hours of fermentation by combination of enhancing aeration and changing the agitation rate. The fast purification method of recombinant protease was conducted with FPLC (Fast Protein Liquid Chromatography). The crude enzyme, treated with ammonium sulfate fractionation and decolored with DEAE-A-50 and polyethylene glycol concentration, was purified with CM-Sephadex-C-50 and Sephadex-G-75. The purified enzyme appears homologous on SDS-PAGE. The purity of enzyme was increased 76.2 times. SDS-PAGE analysis showed that the molecular weights of expressed recombinant products were about 28 kD. The optimal reaction pH and temperature of recombinant enzyme were at pH11 and 60 degrees C, respectively. The recombinant enzyme exhibited high temperature tolerance and was stable at a wide range of pH. Ca2+, MG2+ can enhance the stability of the recombinant enzyme. While the protease activity of the enzyme was strongly inhibited by Hg2+, Ag+, PMFS [symbol: see text] DFP, and was not affected by SDS and Urea.
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PMID:[Study on fermentation condition of alkaline protease gene engineering strain and the purification and characterization of recombinant enzyme]. 1267 45

Visible senescence of the flag tepals in Iris x hollandica (cv. Blue Magic) was preceded by a large increase in endoprotease activity. Just before visible senescence about half of total endoprotease activity was apparently due to cysteine proteases, somewhat less than half to serine proteases, with a minor role of metalloproteases. Treatment of isolated tepals with the purported serine protease inhibitors AEBSF [4-(2-aminoethyl)-benzenesulfonyl fluoride] or DFP (diisopropyl-fluorophosphate) prevented the increase in endoprotease activity and considerably delayed or prevented the normal senescence symptoms. The specific cysteine protease-specific E-64d reduced maximum endoprotease activity by 30%, but had no effect on the time to visible senescence. Zinc chloride and aprotinin reduced maximum endoprotease activity by c. 50 and 40%, respectively, and slightly delayed visible senescence. A proteasome inhibitor (Z-leu-leu-Nva-H) slightly delayed tepal senescence, which indicates that protein degradation in the proteasome may play a role in induction of the visible senescence symptoms. It is concluded that visible senescence is preceded by large-scale protein degradation, which is apparently mainly due to cysteine- and serine protease activity, and that two (unspecific) inhibitors of serine proteases considerably delay the senescence symptoms.
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PMID:Delay of Iris flower senescence by protease inhibitors. 1572 Jun 58


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