Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When denuded ram spermatozoa were suspended in weakly buffered 0.25M sucrose, the acrosin remained bound to the acrosomal membranes of the sperm heads. Media containing CaCl2 caused complete solubilization of the enzyme. Effects of acrosin inhibitors on soluble and bound enzyme were studied in Tris HCl(pH 8.2) containing sucrose. Denuded spermatozoa were used as a preparation of bound acrosin. Trasylol (Kunitz basic pancreatic trypsin inhibitor) acted more strongly on bound scrosin than on soluble acrosin, but soya-bean trypsin inhibitor acted more strongly on soluble acrosin. At concentrations 0.5 - 2.0muM, the inhibitors isolated from ram acrosomes and from ram seminal plasma inhibited soluble acrosin but had negligible effects on bound acrosin. However, bound acrosin was sensitive to high concentrations of the acrosomal inhibitor. The two forms of acrosin were inhibited to about the same degree by p-aminobenzamidine and also by Tos-Lys-CH2Cl. It is proposed that membrane-bound acrosin is the form that functions in penetration of the zona pellucida, and that a role for acrosin inhibitors is suppression of an antifertility effect of soluble acrosin on mammalian eggs. This hypothesis is supported by 1) the results of work on the impaired fertilizing capacity of rabbit spermatozoa that have been treated with acrosin inhibitors, 2) the anti-fertility effects on hamster eggs of solutions of acrosin and of bovine trypsin, and 3) the results in this paper.
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PMID:Effects of acrosin inhibitors on the soluble and membrane-bound forms of ram acrosin, and a reappraisal of the role of the enzyme in fertilization. 124 98

Cellular extracts of Tetrahymena thermophila were found to contain substantial levels of proteolytic activity. Protein digestion occurred over broad ranges of pH, ionic strength, and temperature and was stimulated by treatment with thiol reductants, EDTA and sodium dodecyl sulfate. Incubation at temperatures > or = 60 degrees C or with high concentrations of chaotropic reagents such as 10 M urea or 6 M guanidine-HCl caused an apparent irreversible loss of activity. Activity was also strongly diminished by increasing concentrations of divalent cations. Several peptide aldehydes, p-hydroxymercuribenzoate, and alkylating reagents such as iodoacetate, N-tosyl-L-lysine chloromethyl ketone, N-tosyl-L-phenylalanine chloromethyl ketone, N-methylmaleimide, and trans-epoxysuccinyl-L-leucylamido-(4-guanidino)-butane were potent inhibitors of proteolytic activity. Aprotinin diminished activity by approximately 40% while benzamidine, 3,4-dichlorosocoumarin, and trypsin inhibitors from soy bean, lima bean, and chicken egg caused relatively modest inhibition of proteolytic activity. Phenylmethanesulfonyl fluoride had no apparent effect. Electrophoretic separation of proteins on SDS-polyacrylamide gels copolymerized with gelatin substrate revealed that at least eight active proteolytic enzymes were present in cell extracts ranging in apparent molecular weight from 45,000 to 110,000. Five of these apparent proteases were detected in 70% ammonium sulfate precipitates. Gelatinase activity was not detectable when extracts were pretreated with iodoacetate or E-64, indicating that all of the enzymes observed in activity gels were sensitive to thiol alkylation. Cellular extracts of T. thermophila appeared to contain multiple forms of proteolytic enzymes which were stimulated by thiol reductants and inhibited by thiol modifying reagents. Accordingly, the proteolytic enzymes present in cell extracts appear to be predominantly cysteine proteinases.
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PMID:An assessment of proteolytic enzymes in Tetrahymena thermophila. 145 53

1. PSTI, two chymotrypsinogens and two trypsins were purified to homogeneity by acid extraction, salt fractionation, SP-Sephadex C-50 chromatography and RP-HPLC. 2. A third chymotrypsinogen, a trypsinogen and another trypsin were purified using an alkaline extraction procedure, followed by Trasylol- and Benzamidine-Sepharose affinity chromatography and hydroxylapatite chromatography. 3. The enzymes differed in amino acid composition as well as in specific activities towards synthetic amidase and esterase substrates. 4. N-terminal amino acid sequences were determined for one chymotrypsinogen and one trypsin.
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PMID:The isolation and partial characterization of trypsinogen, pancreatic secretory trypsin inhibitor and multiple forms of chymotrypsinogen and trypsin from the pancreas of the ostrich (Struthio camelus). 161 78

Aprotinin isolated from bovine lungs was covalently immobilized on Eupergit C. The highly selective affinity adsorbent was used to purify trypsin and alpha-chymotrypsin from pancreatic extract in a single step. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis indicated that both enzymes were highly purified. The maximum binding capacity of Eupergit-aprotinin for bovine trypsin was calculated to be ca. 7.5 mg per gram of gel (wet resin).
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PMID:One-step purification of trypsin and alpha-chymotrypsin by affinity chromatography on Eupergit-aprotinin, a novel carrier for purification of serine proteases. 169 97

In canine pancreatitis, irreversible hypotension and death follow saturation of the antiprotease molecules in peritoneal exudate by activated proteolytic enzymes which are released from the pancreas. This study has examined, in rats with taurocholate-induced pancreatitis, the efficacy of removal of the peritoneal exudate by aspiration and a single lavage, followed by instillation of an exogenous antiprotease solution. Instillation of human fresh frozen plasma, containing alpha 2-macroglobulin and alpha 1-antiprotease, was associated with the longest median survival. Aprotinin, although possessing a much greater trypsin inhibitory capacity, just failed to significantly improve the median survival time compared with the control group. Intraperitoneal antiprotease therapy is simple to perform, has a beneficial effect on survival time in this model and merits investigation in man.
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PMID:Effective intraperitoneal antiprotease therapy for taurocholate-induced pancreatitis in rats. 203 16

Proteolytic enzyme inhibitors were examined as absorption enhancers for the nasal delivery of vasopressin (AVP) and desmopressin (1-d-8-DAVP) in rats. Aprotinin, soybean trypsin inhibitor, and camostat mesilate were used as enzyme inhibitors. The nasal absorption of AVP and 1-d-8-DAVP was evaluated by measuring its antidiuretic effect. Nasal administration of AVP (0.005 IU/kg) or 1-d-8-DAVP alone (2.5 ng/kg) produced a small antidiuretic effect. Coadministration with aprotinin (1000 and 10000 KIU/kg) or soybean trypsin inhibitor (1.25 and 6.25 mM) did not change the antidiuretic effect. However, coadministration with camostat mesilate (1 to 50 mM) significantly increased the antidiuretic effect and, thus, the nasal absorption of AVP and 1-d-8-DAVP. The activities of aminopeptidase, cathepsin-B, and trypsin in the nasal mucosal tissue of rats were 7 nmol/min/mg protein, 0.7 nmol/min/mg protein, and 4.6 pmol/min/mg protein, respectively. Aprotinin and soybean trypsin inhibitor inhibited only the trypsin activity, whereas camostat mesilate inhibited aminopeptidase and trypsin activities. Aprotinin (MW 6500) and soybean trypsin inhibitor (MW 8000), with relatively high molecular weights, may not permeate into the nasal mucosal tissue. In contrast, camostat mesilate is slowly absorbed (8%/hr) and could inhibit the proteolytic activity in the nasal mucosa, resulting in enhanced nasal absorption of AVP and 1-d-8-DAVP.
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PMID:Effects of proteolytic enzyme inhibitors on the nasal absorption of vasopressin and an analogue. 172 82

Aprotinin, a protease inhibitor, and promazine, an inhibitor of phospholipase A2, were tested for possible inhibition of pancreatic acinar cell (PAC) decline induced by uncoupling of oxidative phosphorylation with 2,4-dinitrophenol (DNP) or by temporary anoxia/reoxygenation. In incubates of acinar cells isolated from rat pancreas the presence of aprotinin did not influence the survival of cells treated with these noxae. This finding excludes that extracellulary acting trypsin, possibly released from damaged cells, contributes to further cell death. While promazine at concentrations of 15 to 20 nmol.(10(6) cells)-1 was well tolerated by untreated PAC, higher concentrations caused a clear reduction of cell viability. At optimum concentration promazine was without influence on DNP-treated cells, but it had a beneficial effect on survival and morphology of anoxia-treated PAC (p less than or equal to 0.05). Therefore, it can be assumed that after anoxia/reoxygenation the membrane phospholipase A2 becomes stimulated and causes phospholipid depletion with final death of the cells. It is suggested that such a mechanism may contribute to the initial cell damage in the pathogenesis of acute pancreatitis, too.
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PMID:Influence of aprotinin and promazine on survival of isolated pancreatic acinar cells. 172 49

To yield biologically active hormones, prohomones are processed by cleavages at paired basic amino acid residues. In this study we report that a chymotrypsin-like activity has been colocalized with trypsin-like and carboxypeptidase-B-like proteases in neurosecretory granules, the site of intracellular processing of prohomones. Using a peptide of 11 amino acids as a simple model system for the study of prohomone processing, we have identified in neurosecretory granule membranes a novel protease that specifically recognizes and cleaves peptide bonds at aromatic residues. Studies were also performed with the fluorogenic peptide substrate N-succinyl-leucyl-leucyl-valyl-tyrosine-7-amino-4-methyl-coumarine . The identified protease activity is inactivated by a cloromethyl ketone derivative (Tos-Phe-CH2-Cl) by Trasylol, and markedly by phenylmethylsulfonylfluoride and diisopropylfluorophosphate. This activity is colocalized with other prohomone-processing enzymes in neurosecretory granules, which indicates that this activity is involved in the prohomone processing. Alternatively, this activity may function in the degradation of homones and neuropeptides when they are released in synapses.
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PMID:Proteolysis in rat hypothalamic neurosecretory granules: characterization of an alpha-chymotrypsin-like activity in the pathway of intracellular processing of prohormones. 200 13

Isolated mouse calvarial cells having phenotypic characteristics of osteoblasts, mouse parietal bone segments, mouse serum, and control mouse lung fibroblasts were extracted in NaCl and ultrafiltered to recover final concentrates having nominal molecular weights between 50,000 and 1000 daltons. Final concentrates of osteoblasts and bone but not of serum or control fibroblasts were positive for the inhibition of trypsin degradation of fibrin. Osteoblast final concentrates inhibited trypsin hydrolysis of the synthetic substrate p-tosyl-L-arginine methyl ester. Osteoblast and bone final concentrates comigrated with Trasylol but were electrophoretically distinct from alpha 1-antiproteinase. Final concentrates of osteoblast and bone extracts did not inhibit tadpole collagenase using the [3H]glycine-labeled diffuse chick collagen fibril assay. High-performance liquid chromatography (HPLC) of osteoblast final concentrates after purification using immobilized trypsin affinity chromatography revealed the presence of a major peak that was positive for the inhibition of trypsin. Molecular weight determination by HPLC indicated that the inhibitor(s) range in nominal molecular weight from 4300 to 5100 daltons. The presence of low-molecular-weight serine proteinase inhibitory activity in bone suggests its participation in the regulation of bone resorption through the regulation of enzyme activation of collagenase, and possibly its role in defense against bone matrix enzymatic degradation during tumor cell invasion.
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PMID:Osteoblast low-molecular-weight proteinase inhibitor. I. Isolation and characterization of activity from osteoblastic cells and bone. 210 97

Evidence for a kallikrein-kinin system (KKS) in fish is incomplete. In the present study, components of the KKS were identified in rainbow trout. Tissues were assayed for kallikrein-like esterolytic activity using three synthetic kallikrein substrates (TAME, VGAN, and PPAN), and the presence of kallikrein substrate (kininogen) in trout plasma was estimated by bradykinin (BK) radioimmunoassay of plasma activated with trypsin (T). Formation of pressor-depressor substances in vivo by porcine glandular kallikrein (GK) and T was measured after intra-arterial injection into unanesthetized trout. Gill and kidney contained kallikrein activity (TAME and VGAN assays); little activity was observed with PPAN. Aprotinin inhibited gill activity (TAME assay). T liberated 42 +/- 3 (SE) ng (n = 10) of immunoreactive BK per milliliter of plasma. Injection of GK in vivo reduced plasma kininogen levels for over 24 h. GK produced pressor responses only in fish pretreated with the angiotensin-converting enzyme (ACE) inhibitor captopril. This effect was mediated partly through stimulation of alpha-adrenergic receptors. T produced slight pressor responses that were captopril insensitive. These results show that trout possess elements of the KKS system including kallikrein-like enzymatic activity, kininogen, receptor-mediated vascular sensitivity to kallikrein products, and kininolytic activity consistent with ACE (kininase II).
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PMID:Enzymes of the kallikrein-kinin system in rainbow trout. 217 52


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