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)

Rat pancreases were minced and treated with collagenase or collagenase supplemented with chymotrypsin to yield a mixture of ducts, islets, acinar cell clusters, blood vessels, and nerves. Histologically and ultrastructurally, the isolated tissues resembled their in situ counterparts in most respects, the major difference being the destruction of the basement membranes (basal laminae). Ducts ranging in size from the common bile/main pancreatic duct to the intercalated ducts were identified in the digest, although interlobular ducts were most frequently observed. Acinar tissue fragments were separated from nonacinar structures either by flotation through discontinuous gradients of Ficoll or by sieving, the latter technique being the more efficient. Common bile/main ducts, interlobular ducts, and blood vessels were selected manually from the nonacinar fractions. Biochemical analyses showed that the entire nonacinar fraction, as well as isolated ducts and blood vessels, contained larger alkaline phosphatase, carbonic anhydrase, and Mg-ATPase specific activities than acinar tissue, whereas acinar tissue contained larger gamma-glutamyltranspeptidase and amylase activities. However, greater than 63% of the total recovered activity of each enzyme was associated with the acinar tissue. Both the association of the majority of each of these enzyme activities with the acinar tissue and the similarity in specific activities associated with ducts and blood vessels indicate that none of the enzymes tested is a unique marker for interlobular and larger ducts of the pancreas of the rat.
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PMID:Characterization of ducts isolated from the pancreas of the rat. 615 56

Rat and hamster pancreatic ducts were isolated by digestion with collagenase plus chymotrypsin and were cultured for eight weeks in an agarose matrix. Freshly isolated and cultured ducts were characterized morphologically and biochemically. The in vivo morphology of the ducts was maintained in vitro, although certain differences were noted. Both interlobular and intralobular ducts could be identified. gamma-Glutamyltranspeptidase and Mg-ATPase were stable enzymatic activities of the ducts of both species; alkaline phosphatase persisted only in the hamster ducts. Carbonic anhydrase and (Na + K)ATPase were minor activities of the rat ducts. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the rat ducts suggested that actin was the major duct peptide and that the major zymogens were greatly diminished. These results demonstrate that pancreatic ducts can be maintained in vitro and can be used for biochemical studies of this minor pancreatic tissue type.
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PMID:Morphologic and biochemical characteristics of isolated and cultured pancreatic ducts. 616 52

In this study, the effect of sixteen different enzymes on serum C1 and its subcomponents was investigated. The sixteen enzymes could be divided into three groups. First, enzymes which activate native C1: trypsin (optimal concentration 2.4 x 10(-4) mM); alpha-chymotrypsin (2.3 x 10(3) mM); thrombin (1.0 x 10(-5) mM); plasmin (1.9 x 10(-5) mM); elastase (5.8 x 10(-5) mM); pronase (3.0 x 10(-6) mM). All these enzymes are serine esterase and activate native serum C1 bound to EAC4 at the given concentration within 10 min at 30 degrees C. Furthermore, native C1 inhibited by a pentosanpolysulfoester, Sp54, is unable to undergo the internal activation but can be externally activated by the serine esterases. Second, enzymes which do not activate native C1 but result in a dose and time-dependent loss of C1 activity: collagenase; pepsin; carboxypeptidase B. Third, enzymes which have no effect on C1 and C1: Lysozyme; neuraminidase; beta-galactosidase; L-amino acid oxidase; arginase; streptokinase, and acetylcholinesterase.
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PMID:Activation of the first component of complement, C1: comparison of the effect of sixteen different enzymes on serum C1. 619 90

A procedure for dissociation of the nasal salt glands of the domestic duck, Anas platyrhynchos, into suspensions of individual cells has been developed. This technique employs enzymatic digestion with collagenase, hyaluronidase, and chymotrypsin; divalent cation chelation with EDTA; and gentle mechanical dispersion. Average cellular yields of 39 and 26% based on DNA recovered were obtained from the glands of freshwater- and saline-adapted ducks, respectively. Epithelial secretory cells comprised 60-80% of the cell suspensions with the remainder of the populations consisting of endothelial cells, fibroblasts, and blood cells. The dissociated cells were viable as judged by trypan blue exclusion (80-100%, maintenance of ultrastructural integrity, and retention of responsiveness to secretagogues and metabolic inhibitors. Methacholine chloride (0.5 mM) stimulated oxygen consumption by suspensions of both freshwater- and saline-adapted cells, whereas ouabain (0.05 mM) abolished the methacholine-stimulated respiratory response. These cell suspensions provide a promising system for the in vitro study of secretory mechanisms in the avian salt gland.
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PMID:Dissociation of avian salt gland: separation procedures and characterization of dissociated cells. 624 10

Vibrio alginolyticus produces an extracellular collagenase which requires specific induction by collagen or its high-molecular-weight fragments. Peptone also induces collagenase during the late exponential and early stationary growth phases. The peptone inducers have been shown to have a broad molecular weight range between 1,000 and 60,000. The peptone inducers supported slow growth of V. alginolyticus when supplied as the sole nitrogen source in minimal medium. Digestion of the peptone inducers with purified V. alginolyticus collagenase resulted in a decrease in their inducing ability, whereas digestion with trypsin or alpha-chymotrypsin did not. This indicated that induction by the inducers required the presence of collagenase-sensitive bonds. Prolonged digestion of the inducers with collagenase did not completely eliminate the inducing ability of the inducers. The peptone inducers acted as inhibitors of collagenase. A minimal medium induction system has been developed which involves resuspending cells at high density in a medium containing succinate, (NH(4))(2)SO(4), KH(2)PO(4), and the peptone inducer. Cells grown in minimal medium induce earlier than cells grown on peptone, Casamino Acids, or tryptone. Collagenase production was shown to occur for 30 to 60 min in the presence of rifampin at levels which completely inhibit the incorporation of [(3)H]uracil into trichloroacetic acid-precipitable material. Chloramphenicol completely and immediately abolished collagenase production, which together with labeling studies has confirmed that collagenase production involves de novo synthesis of the enzyme. Both glucose and Casamino Acids repressed collagenase production, although synthesis of the enzyme continued for 30 to 60 min after their addition. The repression of collagenase production by glucose and Casamino Acids was more severe than the inhibition of enzyme formation due to addition of rifampin.
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PMID:Peptone induction and rifampin-insensitive collagenase production by Vibrio alginolyticus. 624 22

The amino acid sequence of a collagenolytic protease from the hepatopancreas of the fiddler crab, Uca pugilator, was determined from the structures of overlapping tryptic, chymotryptic, thermolytic, staphylococcal protease, and cyanogen bromide peptides together with automated sequencer analysis of the intact protein. Crab collagenase is a serine protease composed of 226 residues which is capable of degrading the native triple helix of collagen under physiological conditions. When aligned for optimal homology, crab collagenase displays 35% identity with bovine trypsin, 38% with bovine chymotrypsin B, and 32% with porcine elastase. The six half-cystinyl residues in crab collagenase correspond to those forming three of the five disulfide bonds in chymotrypsin. The residues forming the charge relay system of the active site of chymotrypsin (His-57, Asp-102, and Ser-195) are found in corresponding regions in crab collagenase, and the sequences around these residues are well conserved. The primary structure of crab collagenase is the first reported for a serine protease from crustacean hepatopancreas and the first reported for a serine protease possessing the unusual property of being able to degrade native helical collagen.
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PMID:Amino acid sequence of a collagenolytic protease from the hepatopancreas of the fiddler crab, Uca pugilator. 625 53

Ehrlich ascites cells in mice have been shown to have a cell-surface trypsin-like neutral protease (TLNP) with proteolytic and beta-naphthylamidase activity. This activity is inhibited by low-mol.-wt inhibitors of trypsin but not by 11 high-mol.-wt inhibitors of trypsin in free solution. We believe that lack of inhibition is due to protection given to the enzyme by the chemical environment of the cell surface. These cells were demonstrated to export a collagenase zymogen which has been shown to be activated by the cell-surface TLNP. When this protease was completely inhibited by low-mol.-wt inhibitors of trypsin, chymotrypsin was used to activate the collagenase zymogen exported by Ehrlich ascites cells. Examination of the products of collagenolysis at 15 degrees C demonstrated the expected 3/4- and 1/4-length alpha-chain fragments derived from monomeric collagen, confirming that collagenase was one of the enzymes responsible for lysis of the collagen fibrils in the test system.
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PMID:A trypsin-like neutral protease on Ehrlich ascites cell surfaces: its role in the activation of tumour-cell zymogen of collagenase. 625 67

Isolation of cells is nowadays performed by enzymatic means. The influence of such enzymes on the surface coat of mesenchymal and blastemal cells during the dissociation of limbs buds from 11-day-old mouse embryos was studied electron microscopically after staining with ruthenium red. EGTA or collagenase failed to bring about cell separation. The surface coat seemed to be unchanged after collagenase treatment. After EGTA an increase in extracellular filaments was observed. The proteases alpha-chymotrypsin, dispase II, papain, pronase P and trypsin (0.2%, 37 degrees C, 20 min) succeeded in completely dissociating limb buds. Apart from single granules, there was a detachment of the surface coat from the cells in all cases studied. Hyaluronidase led to only partial separation, but the detachment of the surface coat was almost complete, indicating a GAG-rich surface layer on these cells.
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PMID:Changes in the surface coat of mesenchymal cells of mouse limb buds after enzymatic cell separation. 626 Aug 88

An insoluble fibrinolytic enzyme with a molecular weight of approximately 30,000, was purified from the human spleen. A single protein band possessing fibrinolytic activity was obtained on polyacrylamide gel disk electrophoresis at pH 4.5. The enzyme, tentatively termed spleen fibrinolytic proteinase (SFP), degraded fibrinogen at neutral pH following Michaelis-Menten kinetics. The fibrinogenolytic activity was not inhibited by t-AMCHA, a specific plasmin inhibitor. SFP barely degraded certain synthetic ester or polypeptide substrates for trypsin, chymotrypsin, plasma, Xa, elastase and collagenase. These results indicate a different nature for SFP compared to other enzymes examined. SFP was found to digest no elastin and its fibrinogenolytic activity was strongly inhibited by STI, indicating that it was not an elastase. SFP required neither Zn++ nor CA++ for its fibrinogenolytic activity, indicating that it differed from metal-dependent proteinases such as collagenase. SFP was inhibited by DFP but not by TLCK, suggesting that it contains an active serine residue, but no trypsin type histidine at its active center. These results appear to show that SFP is a unique proteinase in the spleen, which is capable of degrading fibrin and fibrinogen at neutral pH.
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PMID:Human spleen insoluble fibrinolytic proteinase acting at neutral pH: its partial purification and characterization. 626 69

The interaction of human blood platelets with collagenase-treated rabbit subendothelium was studied by histochemical ultrastructural methods and by morphometric semi-quantitative analysis. Aortas were deendothelialized and incubated: 1) with a highly purified bacterial collagenase whose specificity was controlled; and 2) with the same collagenase followed by chymotrypsin. For histochemical studies, tannic acid, ruthenium red, and peroxidase-labeled Ricinus communis and concanavalin A were used. Electron microscopy showed that after digestion of fibrillar collagen by collagenase, adherent and aggregated platelets were observed on Ricinus communis-, concanavalin A-, and ruthenium red-positive glycoprotein microfibrils. After successive incubation with collagenase and chymotrypsin, the microfibrils disappeared. No platelets were observed on the remnant amorphous elastin. Morphometric analysis confirmed the interaction of platelets with collagenase-treated subendothelium. In addition, glycoproteins were extracted from collagenase-treated rabbit aortas using 5 M guanidine. Using an in vitro quantitative test, significant platelet adhesion to these glycoproteins was observed. Our results show an interaction between platelets and noncollagenic glycoprotein microfibrils.
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PMID:Histochemical and ultrastructural characterization of subendothelial glycoprotein microfibrils interacting with platelets. 627 53


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