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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study using immunologic methodology confirms previous observations from this laboratory of an absence of a protease component with arginine esterase activity in plasma of patients with cystic fibrosis. In this study, the pooled plasma from control individuals was activated and partially purified after adsorption on columns of soybean trypsin inhibitor conjugated to Sepharose 4B followed by elution with benzamidine. The fraction was further purified by isoelectrofocusing on polyacrylamide gels. Proteins around the pI range of 5.5 were eluted and utilized to prepare an antiserum. Immunoelectrophoresis of activated plasma samples from control subjects and patients with cystic fibrosis was performed utilizing the antiserum. In controls, four precipitin arcs with residual esterase activity were observed, whereas only three were seen in plasma from patients with cystic fibrosis. Double gel diffusion experiments using specific antisera ruled out the presence of trypsin, chymotrypsin, plasminogen, prothrombin, C1 esterase, alpha one-trypsin inhibitor, and inter-alpha-trypsin inhibitor in the concentrated benzamidine eluate. The antisera to alpha two-macroglobulin gave an immunoprecipitate which was readily stained for proteolytic activity. On immunoelectrophoresis, the alpha two-macroglobulin precipitin band corresponded to the band absent in plasma of patients with cystic fibrosis. In contrast, the alpha two-macroglobulin levels were similar in plasma of control subjects and patients with cystic fibrosis. Using the antiserum to the protein fractith proteolytic activity could be demonstrated in control plasma. One specific enzyme-active "rocket" was absent in plasma of patients with cystic fibrosis. In a double blind study of 15 control samples and 15 samples from patients with cystic fibrosis, a specific "rocket" was shown to be present in 13 control samples and absent in 14 cystic fibrosis samples. alpha two-Macroglobulin was determined by both an immunologic procedure and by its trypsin binding (trypsin protein esterase concentration). The ratio of the immunologic assay to the biologic activity assay was 90 for the normal plasma samples and only 65 for cystic fibrosis samples.
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PMID:Absence of an alpha two-macroglobulin-protease complex in cystic fibrosis. 6 Jul 35

Trypsin, thrombin, fibrinolysin, papain, chymothrypsin and urokinase were immobilized on aminopolystyrene resin by the reaction of diazocoupling. An activation of prothrombin and plasminogen and also hydrolysis of fibrin by immobilized enzymes were studied. The immobilized enzymes hydrolyzed N-benzoyl-1-arginine ethyl ester and L-tyrosine ethyl ester. The only preparation of immobilized thrombin possessed the coagulational activity. After the covalent binding trypsin and plasmin maintained the capacity to cause a fibrinolysis. Immobilized trypsin, plasmin, papain, chymotrypsin and urokinase exhibited the fibrinolytic effect due to convertion of plasminogen into plasmin.
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PMID:[Blood coagulating properties of immobilized proteases]. 14 May 25

The tumor promoter phorbol myristate acetate (PMA) induces the production of the serine protease plasminogen activator (PA) in cultures of normal chick embryo fibroblasts (CEF) and synergistically enhances PA production in Rous sarcoma virus-transformed chick embryo fibroblasts (RSVCEF). Following PMA treatment of serum-free RSVCEF cultures, PA induction is accompanied by distinct morphological changes, including enhanced cell clustering and the formation of dense cellular aggregates. These alterations in the morphology of the PMA-treated transformed cells are inhibited by several protease inhibitors, including leupeptin, NPGB, SBTI, benzamidine and DFP, the specific inhibitor of serine enzymes. A number of protease inhibitors are ineffective in preventing the PMA-induced morphological changes; these include inhibitors of trypsin, chymotrypsin, elastase, thrombin and, most importantly, plasmin. The use of a fluorescent substrate to assay PA directly demonstrated that the pattern of inhibiton of PA activity correlates exactly with the inhibition of morphological changes. The of 3H-DFP to label and characterize serine zymes in the culture fluid from PMA-treated cells further indicated that PA is the serine protease responsible for the morphological changes. Thus PA itself can catalytically alter cellular behavior in culture independent of plasminogen, until not its only known natural substrate.
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PMID:Phorbol ester-induced morphological changes in transformed chick fibroblasts: evidence for direct catalytic involvement of plasminogen activator. 22 74

Granule and post-granular-supernatant fractions were obtained from pig leucocyte cells by differential centrifugation in 0.34 M sucrose. Granule extract possesses proteinase activity at acid and at neutral pH. Three groups of neutral and a group of acid proteinases were isolated from granule extracts by chromatography on DEAE-cellulose. In the first group are present elastase-like and plasminogen-activator proteinases, that are inhibited by diisopropylphosphorofluoridate, alpha1-antitrypsin, intracellular leucocyte inhibitor and partly with p-aminomethylbenzoic acid and Trasylol. The second group of neutral proteinases is unstable under the conditions of isolation used the third group of neutral proteinases comprises collagenases that are inhibited by ethylenediamine tetraacetic acid disodium salt, alpha1-antitrypsin and leucocyte inhibitor. The acid proteinases are inhibited only with pepstatin, up to 90%. In the post-granular supernatant was found the acid proteinase activity towards hemoglobin and casein, and non-stable neutral proteolytic activity towards bovine serum albumin and serum gamma globulin. In the post-granular supernatant also the inhibitors of neutral proteinases were found. By gel filtration on Sephadex G-100 and ion-exchange chromatography on CM-cellulose two inhibitors of neutral proteinases were isolated. The majority of the inhibitor capacity (about 80%) of post-granular supernatant was eluted together with ovalbumin (Mr 43000) and the remainder with cytochrome c (12300). These inhibitors inhibit the granule neutral proteinases, acting on all substrates used, but do not inhibit granule acid proteinase. Inhibition effects of post-granular-supernatant inhibitors on trypsin and chymotrypsin were obtained only when bovine serum albumin was used as substrate. Inhibitors of post-granular supernatant are stable at pH 6-8, but unstable in the pH rnage 2-5 and are thermolabile.
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PMID:Intracellular distribution of neutral proteinases and inhibitors in pig leucocytes. Isolation of two inhibitors of neutral proteinases. 24 Jul 15

We have raised four monoclonal antibodies recognizing different epitopes within the human cell-surface receptor for urokinase-type plasminogen activator (u-PA). One of these antibodies completely abolishes the potentiation of plasmin generation observed upon incubation of the zymogens pro-u-PA and plasminogen with U937 cells. This antibody, which is also the only one to completely inhibit the binding of DFP-inactivated [125I]-u-PA to U937 cells, is directed against the u-PA binding NH2-terminal domain of u-PAR, a well-defined fragment formed by limited chymotrypsin digestion of purified u-PAR, demonstrating the functional independence of the u-PA binding domain as well as the critical role of u-PAR in the assembly of the cell-surface plasminogen activation system.
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PMID:Cell-induced potentiation of the plasminogen activation system is abolished by a monoclonal antibody that recognizes the NH2-terminal domain of the urokinase receptor. 171 92

alpha 2-Antiplasmin (alpha 2AP), a serpin proteinase inhibitor with two methionine residues in its reactive center, was treated with cis-dichlorodiammineplatinum (II) (cis-DDP). This compound has been utilized previously to specifically modify methionine residues. After reaction, the alpha 2AP demonstrated decreased inhibitory activity against plasmin, miniplasmin, trypsin and chymotrypsin. The reduction in activity depended on the concentration of cis-DDP; however, the amount of activity retained by the treated alpha 2AP was equivalent with each of the four proteinases. alpha 2AP that was incubated with 1.0 mM cis-DDP for 3 h at 37 degrees C was 90% inactivated. These same conditions resulted in the binding of only 1.0-1.5 mol of platinum per mol of inhibitor. In experiments with lower concentrations of cis-DDP, the amount of incorporated platinum directly correlated with the amount of inactivated alpha 2AP (1:1 stoichiometry). Reactions and functions of alpha 2AP that do not result in proteinase inhibition were not affected by cis-DDP. Cleavage of alpha 2AP by elastase, which occurs near the proteinase inhibition site, was unaffected. In addition, the affinity of alpha 2AP for the K1-3 region of plasminogen remained unchanged after treatment. These data strongly suggest that the reaction of alpha 2AP with cis-DDP involves principally a single site on the inhibitor and that this site is critical for proteinase inhibitory activity. The most likely candidate is the P'1 methionine which is adjacent to the peptide bonds cleaved in the proteinase inhibitory reactions but not in the elastase reaction.
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PMID:Inactivation of alpha 2-antiplasmin by limited reaction with cis-dichlorodiammineplatinum (II) 252 Dec 1

Tissue plasminogen activator was treated with Sepharose-bound trypsin or chymotrypsin. Trypsin rapidly converted the one-chain activator to the two-chain form. This caused a marked increase in the amidolytic activity, while plasminogen activation initially increased but then decreased again. SDS/polyacrylamide gel electrophoresis in combination with [3H]diisopropylfluorophosphate active-site labeling revealed that after the conversion to the two-chain activator a minor cleavage occurred in the B chain, while the A chain was substantially degraded. Chymotrypsin caused a marked decrease in both amidolytic activity and plasminogen activation. SDS/polyacrylamide gel electrophoresis under reducing conditions revealed that two pairs of new bands had appeared, with Mr or about 50,000/52,000 and 17,000/20,000 respectively. N-terminal sequence analysis identified cleavage sites at peptide bonds 420-421 and 423-424. These bonds are located in a region of the activator which is homologues to the segments of trypsin and chymotrypsin, where autocatalytic cleavages occur during their activations. However, treatment of two-chain activator with chymotrypsin had markedly less effect on plasminogen activation and amidolytic activity. By treatment of samples of chymotrypsin-digested one-chain activator with plasmin, amidolytic activity could be largely restored. Thus, chymotrypsin may, by cleaving bonds 420-421 and 423-424, convert the active one-chain activator into an 'inactive' zymogen, which is again 'activated' by plasmin cleavage.
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PMID:Proteolytically induced variations in the enzymatic properties of tissue plasminogen activator. Activations, inactivations and reactivations. 294 92

Plasminogen Activator (PA) and its response to glucocorticoids and androgens was studied in viable rat thymocytes in suspension. PA was measured by its ability to convert plasminogen to plasmin, and the formed plasmin determined by cleavage of 14C-labeled globin. Using this functional assay, PA was found to be associated with the outer surface of thymic cells, and only negligible activity recovered from the incubation medium. Rat thymocytes also contain cytoplasmic and nuclear inhibitor(s) of the serine proteases plasmin, trypsin, chymotrypsin and thymic PA. Release of these inhibitors prevented determination of thymic PA activity in presence of lysed cells. The specific activity of PA in thymocytes isolated from adrenalectomized-castrated rats did not differ significantly from the specific activity associated with cells from intact animals. Furthermore, treatment of adrenalectomized-castrated rats with 0.1 mg of dexamethasone/kg for 2 days induced thymic involution without affecting thymic PA activity. These observations suggest that PA activity of thymocytes is not involved in glucocorticoid-mediated thymic involution.
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PMID:Plasminogen activator and protease inhibitor activities in isolated rat thymocytes. 315 48

A persistent puzzle in our understanding of hemostasis has been the absence of hemorrhagic symptoms in the majority of patients with Hageman trait, the hereditary deficiency of Hageman factor (factor XII). One proposed hypothesis is that alternative mechanisms exist in blood through which plasma thromboplastin antecedent (PTA, factor XI) can become active in the absence of Hageman factor. In order to test this hypothesis, the effect of several proteolytic enzymes, among them thrombin, plasma kallikrein, and trypsin, was tested upon unactivated PTA. PTA was prepared from normal human plasma by Ca(3)(PO(4))(2) adsorption, ammonium sulfate fractionation, and successive chromatography on QAE-Sephadex (twice). Sephadex-G150, and SP-Sephadex. The partially purified PTA was almost all in its native form, with a specific activity of 45-70 U/mg protein; the yield was about 10%. It contained no measurable amounts of other known clotting factors, plasmin, plasminogen, nor IgG. Incubation of PTA with trypsin generated potent clot-promoting activity that corrected the abnormally long clotting time of plasma deficient in Hageman factor or PTA but not in Christmas factor. This clot-promoting agent behaved like activated PTA on gel filtration (apparent molecular weight: 185,000) and was specifically inhibited by an antiserum directed against activated PTA. These data suggested that PTA can be converted into its active form by trypsin. PTA was not activated by thrombin, chymotrypsin, papain, ficin, plasmin, plasma kallikrein, tissue thromboplastin, or C. Trypsin converted PTA to its active form enzymatically. Whether trypsin serves to activate PTA in vivo is not yet clear.
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PMID:Partial purification of plasma thromboplastin antecedent (factor XI) and its activation by trypsin. 426 22

Structural studies on a hereditarily abnormal plasminogen, plasminogen Tochigi, have been performed to identify the difference responsible for its lack of proteolytic activity. The plasminogen sample used was from a heterozygote and thus consisted of apparently equal amounts of normal and defective plasminogen molecules. Amino acid sequence analysis of a tryptic peptide isolated from the abnormal plasminogen indicated that Ala-600 (equivalent to Ala-55 in the chymotrypsin numbering system) had been replaced by Thr. No other substitutions in the active-site residues--namely, His-57, Asp-102, and Ser-195--were found. Molecular models for chymotrypsin and the bovine trypsin-pancreatic trypsin inhibitor complex indicate that Ala-55 is very near the active-site His. The Thr at position 55 in plasminogen (plasmin) Tochigi may perturb His-57 such that the proton transfers associated with the normal catalytic process cannot occur in the abnormal plasmin.
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PMID:Plasminogen Tochigi: inactive plasmin resulting from replacement of alanine-600 by threonine in the active site. 621 75


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