Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously demonstrated the existence of two types of endopeptidase in Escherichia coli. A purification procedure is described for one of these, designated protease II. It has been purified about 13,500-fold with a recovery of 24%. The isolated enzyme appears homogeneous by electrophoresis and gel filtration. Its molecular weight is estimated by three different methods to be about 58,000. Its optimal pH is around 8. Protease II activity is unaffected by chelating agents and sulfhydryl reagents. Amidase and proteolytic activities are stimulated by calcium ion, which decreases the enzyme stability. Like pancreatic trypsin, this endopeptidase catalyses the hydrolysis of alpha-amino-substituted lysine and arginine esters. It appears distinct from the previously isolated protease I, which is a chymotrypsin-like enzyme. The apparent Michaelis constant for hydrolysis of N-benzoyl-L-arginine ethyl ester is 4.7 X 10(-4) M. The esterase activity is inhibited by diisopryopylphosphorofluoridate (Ki(app) equals 2.7 X 10(-3) M) and tosyl lysine chloromethyl ketone (Ki(app) equals 1.8 X 10(-5) M), indicating that serine and histidine residues may be present in the active site. However, protease II is insensitive to phenylmethanesulfonyl fluoride and several natural trypsin inhibitors. Its amidase and esterase activities are competitively inhibited by free arginine and aromatic amidines. The proteolytic activity measured on axocasein is very low. In contrast to trypsin, protease II is without effect on native beta-galactosidase. It easily degrades aspartokinase I and III. Nevertheless both enzymes are resistant to proteolysis in the presence of their respective allosteric effectors. These results provide further evidence that such differences in protease susceptibility can be related to the conformational state of the substrate. The possible implication of structural changes in the mechanism of preferential proteolysis in vivo, is discussed.
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PMID:Protease II from Escherichia coli. Purification and characterization. 24 Aug 39

The degradation of neurotensin and D-Tyr11 neurotensin by apparently homogeneous preparations of rabbit brain endo-oligopeptidase A and endo-oligopeptidase B (Proline-endopeptidase) was studied. Peptide fragments were isolated by high performance liquid chromatography and identified by amino acid analysis. Endo-oligopeptidase A cleaved neurotensin at the Arg8-Arg9 bond whereas D-Tyr11 neurotensin was not significantly hydrolysed. Endo-oligopeptidase B cleaved at the carboxyl side of Pro7, Pro10 in neurotensin and at Pro7 in D-Tyr11 neurotensin. The concentration dependent inhibition of neurotensin degradation by bradykinin and vice-versa represents additional evidence that endo-oligopeptidase A cleaves both Phe5-Ser6 bond of bradykinin and the Arg8-Arg9 bond of neurotensin.
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PMID:Degradation of neurotensin by rabbit brain endo-oligopeptidase A and endo-oligopeptidase B (proline-endopeptidase). 631 69

In the present study we investigated the possible participation of endo-oligopeptidase B (poline-endopeptidase) in the control of gonadotrophin secretion through the control of LH-RH inactivation. This enzyme selectively hydrolyzes the Pro9-Gly10-NH2 peptide bond of LH-RH, thereby inactivating this substance. The enzyme activity was evaluated using a specific colorimetric substrate, i.e., Z-Gly-Pro-SM. Female adult Wistar rats were submitted to castration, experimental situations that are known to produce changes in gonadotrophin secretion. Hypothalamic and pituitary endo-oligopeptidase B activity was shown to be present predominantly in the soluble fraction of the enzyme preparations. The results also indicated that endo-oligopeptidase B activity adult female rat pituitary decreased after castration and increased after administration of estradiol and progesterone to castrated animals. The present results lead us to suggest that anterior pituitary endo-oligopeptidase B may be related to the control gonadotrophin secretion in female rats.
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PMID:Effect of gonadal steroids on hypothalamus and anterior pituitary endo-oligopeptidase B (proline-endopeptidase) activity in castrated female rats. 639 Mar 58

Oligopeptidase B is a serine endopeptidase found in prokaryotes, unicellular eukaryotes and higher plants. The enzyme has been shown recently to play a central role in the pathogenesis of several parasitic diseases such as African trypanosomiasis, and to be a potential therapeutic target. This study reports that protamine, a basic peptide rich in arginine, is a potent inhibitor at the nanomolar level of oligopeptidase B from E. coli and wheat. Protamines 1B, 2C, 3A and TP17 displayed similar inhibitory activities and were capable of binding strongly to oligopeptidase B without proteolytic cleavage. The concentration of protamine needed for 50% inhibition (IC50) of oligopeptidase B was 10(4)-fold lower than the IC50 of trypsin. Oligopeptidase B was highly sensitive to inhibition by protamines even in the presence of serum (IC50, 1 microM). These data indicate that protamines might provide information useful for the design of more specific synthetic oligopeptidase B inhibitors.
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PMID:Protamine: a unique and potent inhibitor of oligopeptidase B. 1594 39

Wheat is prone to strawbreaker foot rot (eyespot), a fungal disease caused by Oculimacula yallundae and O. acuformis. The most effective source of genetic resistance is Pch1, a gene derived from Aegilops ventricosa. The endopeptidase isozyme marker allele Ep-D1b, linked to Pch1, has been shown to be more effective for tracking resistance than DNA-based markers developed to date. Therefore, we sought to identify a candidate gene for Ep-D1 as a basis for a DNA-based marker. Comparative mapping suggested that the endopeptidase loci Ep-D1 (wheat), enp1 (maize), and Enp (rice) were orthologous. Since the product of the maize endopeptidase locus enp1 has been shown to exhibit biochemical properties similar to oligopeptidase B purified from E. coli, we reasoned that Ep-D1 may also encode an oligopeptidase B. Consistent with this hypothesis, a sequence-tagged-site (STS) marker, Xorw1, derived from an oligopeptidase B-encoding wheat expressed-sequence-tag (EST) showed complete linkage with Ep-D1 and Pch1 in a population of 254 recombinant inbred lines (RILs) derived from a cross between wheat cultivars Coda and Brundage. Two other STS markers, Xorw5 and Xorw6, and three microsatellite markers (Xwmc14, Xbarc97, and Xcfd175) were also completely linked to Pch1. On the other hand, Xwmc14, Xbarc97, and Xcfd175 showed recombination in the W7984 x Opata85 RIL population suggesting that recombination near Pch1 is reduced in the Coda/Brundage population. In a panel of 44 wheat varieties with known eyespot reactions, Xorw1, Xorw5, and Xorw6 were 100% accurate in predicting the presence or absence of Pch1 whereas Xwmc14, Xbarc97, and Xcfd175 were less effective. Thus, linkage mapping and a germplasm survey suggest that the STS markers identified here should be useful for indirect selection of Pch1.
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PMID:Identification of a candidate gene for the wheat endopeptidase Ep-D1 locus and two other STS markers linked to the eyespot resistance gene Pch1. 1795