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)

Interactions between native terrylytin and trypsin and their derivatives modified by water-soluble dextrans on one hand and human blood serum inhibitors on the other, were studied. It was shown that modification of the enzymes results in changes in the type of their inhibition by blood serum due to a decrease of affinity of polymeric enzyme forms for alpha 2-macroglobulin and alpha 1-antitrypsin. The inhibition constants for native and modified forms of terrylytin and trypsin were calculated. The effects of steric and electrostatic factors on the interaction between inhibitors of blood and polymeric forms of proteinases are discussed.
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PMID:[Interactions between human blood serum inhibitors and native and modified dextran proteinases--terrilytin and trypsin]. 8 89

Interactions between the serine proteinase trypsin and the protein proteinase inhibitors in human blood were expressed in terms of a coupled set of non-linear differential equations, which has been solved for each of 110 samples of serum obtained from colleagues and from a variety of hospital sources. Optimization of nine unknown theoretical parameters and 21 experimental rate measurements of the hydrolytic activity of trypsin in free and bound states after admixture with various amounts of a given serum was achieved by an iterative procedure using initial estimates of the parameters derived from the "four-straight-line" model described in the preceding paper [Topping & Seilman (1979) Biochem. J. 177, 493--499.] Such a procedure yielded the following information for each sample of serum examined: (a) the concentrations of alpha 1-antitrypsin and alpha 2-macroglobulin; (b) the unequivocal assignment of alpha 2-macroglobulin into one of seven categories on the basis of trypsin binding in two kinetically differentiated modes (alpha and beta); (c) the hydrolytic activities of trypsin (versus Bz-Arg-OEt) when bound to alpha 1-antitrypsin, and to alpha 2-macroglobulin in the alpha- and beta-modes. Molecular interpretations of the binding of trypsin to alpha 2-macroglobulin are discussed and the potential clinical value of recognizing the nature of such binding is reported.
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PMID:The identification of distinctive forms of human alpha 2-macroglobulin by using the numerical relationship between trypsin binding in alpha- and beta-modes. 8 56

A modified spectrophotometric method is developed for simultaneous estimation of alpha 1-antitrypsin and alpha 2-macroglobulin in human blood serum (plasma); the method is based on dissimilar interaction of these inhibitors with trypsin in the systems with a low molecular substrate N-alpha-benzoyl-l-arginine ethyl ester. alpha 1-Antitrypsin was estimated by inhibition of the arginine esterase activity of trypsin in a mixture containing human blood serum diluted 50-fold. alpha 2-Macroglobulin was estimated by maintained arginine esterase activity of the trypsin-alpha 2-macroglobulin complex, formed after interaction of an excess of trypsin with blood serum, diluted 10-fold and after subsequent inactivation of free, unbound with alpha 2-macroglobulin, trypsin by treatment with the soy bean inhibitor of trypsin. alpha 1-Antitrypsin and alpha 2-macrog-obulin were estimated by means of the method described in blood serum of healthy persons and in patients with burns or with carcinoma of pancreas. The method enables to estimate two main inhibitors of blood plasma proteinases in a small volume of blood serum (0.1 ml) very rapidly and specifically using commercially available substrate; the method might be recommended for routine clinical analysis.
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PMID:[Uniform method for determining the alpha 1-antitrypsin and alpha 2-macroglobulin activity in human blood serum (plasma)]. 8 58

The molecular forms of immunoreactive pancreatic cationic trypsin in sera of patients with acute pancreatic inflammation have been characterized using a radioimmunoassay technique that is capable of detecting trypsinogen as well as trypsin bound to alpha 1-antitrypsin. Trypsin bound to alpha 2-macroglobulin is not immunoreactive under normal assay conditions. However, alpha 2-macroglobulin-bound trypsin can be detected after gel filtration of serum on Bio-Gel A-0.5 m and acid treatment of column fractions. The average serum level of immunoreactive cationic trypsin from 20 patients with acute pancreatic inflammation was 1,590 ng/ml. An average normal value of 26 ng/ml has been obtained previously. Serum samples from 14 patients with pancreatic inflammation were chromatographed under conditions that resolve trypsinogen, alpha 1-antitrypsin-bound trypsin, and alpha 2-macroglobulin-bound trypsin. In each case, the major portion of the immunoreactive material eluted at a position corresponding to free trypsinogen, while a minor fraction of the immunoreactive material appeared to be trypsin bound to alpha 1-antitrypsin. The zymogen nature of the major peak was confirmed in one case by activation with human enteropeptidase. In 11 of 14 patients, acid treatment of the alpha 2-macroglobulin peak yielded immunoreactive trypsin.
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PMID:Molecular forms of immunoreactive pancreatic cationic trypsin in pancreatitis patient sera. 9 23

The activation of canine anionic and cationic trypsinogen by enterokinase, trypsin, thrombin, plasmin and extracts from canine granulocytes were studied in vitro. Enterokinase activates both trypsinogens about 1000 times faster than trypsin. The enterokinase-catalyzed activation is not inhibited by the main serum protease inhibitors, alpha-macroglobulin and alpha 1-antitrypsin. alpha-Macroglobulin cannot inhibit the activation of the trypsinogens by trypsin but this reaction is completely inhibited by alpha 1-antitrypsin. The results are discussed in relation to the pathogenesis of acute pancreatitis.
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PMID:Studies on the activation of canine trypsinogens in vitro. 9 42

Twenty three patients with acute pancreatitis were studied to assess the serum alpha 1-antitrypsin levels as well as the total trypsin-inhibitor capacity. These parameters were found to be normal or increased, which is not the case with patients with chronic pancreatitis. The value of protease-inhibitor treatment in acute pancreatitis is doubted.
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PMID:Alpha 1-antitrypsin and total trypsin-inhibitor capacity in acute pancreatitis. 11 90

The present work was undertaken to explore the effect of two purified neutral proteases derived from human peripheral blood polymorphonuclear leukocytes (PMN) on articular cartilage as a model of joint injury. Human leukocyte elastase and chymotrypsin-like enzyme, purified by affinity chromatography, released 32SO4 from labeled rabbit articular cartilage slices in vitro. Release of isotope was initially delayed, suggesting that either a lag in enzyme penetration occurs or that size of degradation fragments is a limiting factor in diffusion of label out of the tissue. The release of 35SO4 was inhibited by preincubation of elastase and chymotrypsin-like enzyme with human alpha 1-anti-trypsin, or with their specific chloromethyl ketone inactivators, and the action of elastase was also inhibited by a monospecific antiserum to PMN elastase, freed of major serum proteinase inhibitors. Immunohistochemical staining procedures revealed the presence of PMN elastase inside the matrix of cartilage slices after a 20-min exposure of tissue to either the pure enzyme or crude PMN granule extract. Serum alpha 1-antitrypsin failed to penetrate into the cartilage slices under identical in vitro conditions. In association with the results reported in the accompanying paper, these findings suggest a model of cartilage matrix degradation by PMN neutral proteases in which local protease-antiprotease imbalance, coupled with different rates of penetration of protease and antiprotease into target tissue, plays a key role in accounting for matrix damage.
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PMID:Degradation of cartilage proteoglycan by human leukocyte granule neutral proteases--a model of joint injury. I. Penetration of enzyme into rabbit articular cartilage and release of 35SO4-labeled material from the tissue. 12 82

Chowdhury and Louria [1] reported that cadmium could reduce in vitro the concentration and the trypsin inhibitory capacity of plasma alpha 1-antitrypsin. They suggested that this could explain the emphysema observed in some workers exposed to cadmium. Using the same experimental approach as these authors, we could not reproduce their observations. Furthermore, in vivo results obtained on workers excessively exposed to cadmium during more than 20 years and exhibiting obvious signs of chronic cadmium intoxication did not reveal a decrease in the concentration and the activity of plasma alpha 1-antitrypsin.
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PMID:alpha 1-antitrypsin in cadmium toxicity: an evaluation of its suggested role. 20 88

Sequential extraction of bovine corneal homogenates with aqueous 0.154M NaCl, 0.5M NaCl and 3M guanidine HCl revealed the presence, in the two sodium chloride extracts, of trypsin inhibitory factors. Upon gel-filtration chromatography of the o.5M NaCl soluble corneal material on Sephadex G-75, two peaks with trypsin inhibitory activity were resolved. One peak was eluted in the void volume, whereas a second peak had mobility corresponding to a molecular weight fraction much lower than, and therefore distinct from, alpha 1-antitrypsin inhibitor. The possible implication of this inhibitory factor in the pathogenesis of corneal ulceration is briefly discussed.
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PMID:Demonstration of a protease inhibitor in the cornea. 22 6

The synovial fluid (SF) of RA patients contains large amounts of PMN which are well equipped with neutral enzymes to degrade articular cartilage: elastase and cathepsin G, which both destroy proteoglycans and native collagen, as well as 2 types of collagenoases. Indirect evidence suggests that PMN might be important in the destruction of RA articular cartilage. In 19 SF of RA patients no free elastase or collagenase was found. Using immune histochemical methods, we observed that PMN and macrophages of SF contain both elastase and alpha 1-anti-trypsin and alpha 2-macroglobulin. Peripheral PMN - but not monocytes - contain elastase, however both types of cells lack alpha 1-antitrypsin and alpha 2-macroglobulin. Elastase is demonstratable in the superficial layer of pannus free RA articular cartilage. These findings suggest that neutral proteinases from PMN in RA SF are generally neutralized by physiologic inhibitors and removed by phagocytes. The enzyme-inhibitor interaction might be bypassed during "frustrated phagocytosis" so that enzymes like PMN elastase can damage RA articular cartilage.
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PMID:[Chronic polyarthritis: role of polymorphonuclear leukocytes in the destruction of pannus-free articular cartilage]. 23 68


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