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:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the effect of short-term (3 h) pancreatic duct obstruction (PDO) on the exocrine pancreas and on the secretion of lysosomal enzymes into the pancreatic juice of rabbits during stimulation by pancreatic secretagogues. The following evaluations were made: serum amylase levels, pancreatic water content, pancreatic amylase, trypsinogen and cathepsin B content, and output of pancreatic enzymes and lysosomal hydrolases when stimulated by secretin and caerulein as well as the distribution of cathepsin B in subcellular fraction. Cellular fragility (LDH leakage from dispersed acini) and subcellular organellar fragility (cathepsin B leakage from lysosomes and malate dehydrogenase leakage from mitochondria) were also evaluated. PDO for 3 h plus secretin infusion caused a significant rise in serum amylase levels, pancreatic water content, and pancreatic amylase and trypsinogen content due to congestion of digestive enzymes during PDO. There was also a redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction and increased cellular and subcellular organellar fragility. In normal rabbits and in those with only secretin infusion, caerulein stimulated the secretion of cathepsin B into pancreatic juice. Just after PDO, the secretion of cathepsin B, amylase and trypsinogen significantly decreased. By 24 h after PDO, the output of cathepsin B stimulated by caerulein and secretin had increased significantly. Amylase and trypsinogen output were also significantly increased at this stage, in both the secretin and caerulein fractions. These results indicate that the secretion of lysosomal enzymes into pancreatic juice is stimulated by gut hormones, such as caerulein, in the normal physiological state and in pathological states, such as PDO. These results also show an important role of increased cellular and subcellular organellar fragility in the pathogenesis of pancreatic injuries induced by PDO and augmented secretion of both lysosomal enzymes and pancreatic digestive enzymes in the recovery stage after PDO and their important roles at this stage. Lysosome enzymes also seem to play some physiological roles in the pancreatic ductal system in normal physiological states as well as their roles in pathological states, because cathepsin B can activate trypsinogen, and trypsin can activate many other enzymes.
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PMID:Effect of short-termed pancreatic duct obstruction on the pancreatic subcellular organellar fragility and pancreatic lysosomal enzyme secretion in rabbits. 138 8

Limited proteolysis of phospholipid complexes of heart and muscle bovine lactate dehydrogenase by trypsin and chymotrypsin has been studied under nondenaturing condition at pH 7.5. Chymotrypsin cleaves the polypeptide chain of heart and muscle lactate dehydrogenase into two principal fragments and LDH subunits were protected by lipids towards the proteinase attack. Enzymatic activity of heart and muscle lactate dehydrogenase was abolished by limited proteolytic cleavage. In complexes, both isoenzymes were protected against proteinases attack by lipids.
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PMID:Limited proteolysis of bovine muscle and heart lactate dehydrogenase is inhibited by phospholipid liposome interaction. 239 38

Lactate dehydrogenase C4 (LDH-C4) is an antigenic protein that occurs only in spermatozoa and the mature testis. The antibody-combining sites of this enzyme were mapped by measuring the binding of anti-LDH-C4 by isolated peptides. Pure mouse LDH-C4 was digested with trypsin, and the resulting fragments were fractionated by reverse-phase high-pressure liquid chromatography. Rabbit anti-mouse LDH-C4 bound to 13 pure peptides. Amino acid compositions and partial or complete sequencing by the Edman degradation was used to identify eight of these fragments in the complete structure of the molecule. The relationship between structure and antigenicity of these peptides is discussed in detail. These data fit best to the domain model of protein antigenicity. This antigenic map of LDH-C4 will be useful in the design of a synthetic contraceptive vaccine.
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PMID:Antigenic domains of the sperm-specific lactate dehydrogenase C4 isozyme. 241 Jul 78

Daily intraperitoneal injections of acetaldehyde for 10 days to adult rats produced distinct morphological and biochemical changes in the exocrine pancreas, without affecting the body weight, pancreatic weight, and DNA, RNA, and protein content of the pancreas. By electronmicroscopy, although the number and size of the acinar zymogen granules appeared to be the same between the saline- and acetaldehyde-treated rats, the zymogen granules of the latter group showed decreased osmiophilia. Acinar mitochondria of the acetaldehyde-treated rats were found to be slightly swollen with dense granules, and plasma membrane fragments were often seen in the acinar lumen. Administration of acetaldehyde significantly decreased immunoreactive cationic trypsin (ogen) and total amylase activity in the pancreas, but not in the serum, where amylase activity was markedly increased. Basal secretion of amylase, trypsinogen, and chymotrypsinogen from isolated dispersed pancreatic acini of acetaldehyde-treated rats was increased by 40-50%. Nicotine (5-25 mM) induced a profound increase in secretion of the same enzymes from isolated acini of both saline- and acetaldehyde-treated rats, but in the latter group there was a concomitant rise in LDH release. Furthermore, CCK-8 (1 nM), secretin (1 microM), and carbachol (10 microM) either alone or in combination with nicotine (12.5 mM) produced a profound stimulation in amylase, trypsinogen, and chymotrypsinogen secretion from acini of both groups of rats. On the other hand, secretion of 3H-pulse-labeled proteins from isolated acini of acetaldehyde-treated rats by nicotine was decreased by approximately 50% compared with the controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Morphological and biochemical changes of the pancreas in rats treated with acetaldehyde. 242 52

Dimethylthiourea (DMTU) progressively disappeared following reaction with increasing amounts of hydrogen peroxide (H2O2) in vitro. DMTU disappearance following reaction with H2O2 was inhibited by addition of catalase, but not aminotriazole-inactivated catalase (AMT-catalase), superoxide dismutase (SOD), mannitol, benzoate or dimethyl sulfoxide (DMSO) in vitro. By comparison, DMTU disappearance did not occur following addition of histamine, oleic acid, elastase, trypsin or leukotrienes in vitro. Addition of DMTU also decreased H2O2-mediated injury to bovine pulmonary artery endothelial cells (as reflected by LDH release) and DMTU disappeared according to both added amounts of H2O2 and corresponding degrees of injury. DMTU disappearance was also relatively specific for reaction with H2O2 in suspensions of endothelial cells where it was prevented by addition of catalase, but not AMT-catalase or SOD and did not occur following sonication or treatment with elastase, trypsin or leukotrienes. Addition of washed human erythrocytes (RBC) also prevented both H2O2 mediated injury and corresponding DMTU decreases in suspensions of endothelial cells. In addition, phorbol myristate acetate (PMA) and normal neutrophils, but not O2 metabolite deficient neutrophils from patients with chronic granulomatous disease (CGD), caused DMTU disappearance in vitro which was decreased by simultaneous addition of catalase, but not SOD, sodium benzoate or DMSO. Finally, addition of normal neutrophils (but not CGD neutrophils) and PMA caused DMTU disappearance and increased the concentrations of the stable prostacyclin derivative (PGF1 alpha) in supernatants of endothelial cell suspensions. In parallel, DMTU also decreased PMA and neutrophil-mediated PGF1 alpha increases in supernatants from endothelial cell monolayers. Our results indicate that DMTU can decrease H2O2 or neutrophil mediated injury to endothelial cells and that simultaneous measurement of DMTU disappearance can be used to improve assessment of the presence and toxicity of H2O2 as well as the H2O2 inactivating ability of scavengers, such as RBC, in biological systems.
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PMID:Dimethylthiourea prevents hydrogen peroxide and neutrophil mediated damage to lung endothelial cells in vitro and disappears in the process. 254 52

The inactivation by hydrostatic pressure of muscle-type lactate dehydrogenase (M4-LDH, EC 1.1.1.27; L-lactate: NAD+ oxidoreductase) homologues from five shallow-living and six deep-living marine teleost fishes was compared. The pressures which inactivate these enzymes are much higher than the pressures experienced by any of the species. To determine whether hydrostatic pressure effects on protein aggregation state and conformation might influence proteolysis, the inactivation of LDH by the proteases, trypsin (EC 3.4.21.4) and subtilisin (EC 3.4.4.16) was determined at atmospheric pressure and 1,000 atm pressure. At 10 degrees C and atmospheric pressure, the enzymes of the shallow-living fishes are inactivated four times faster by trypsin and three times faster by subtilisin than are the homologues of the deep-living species. At 1,000 atm pressure, the homologues of shallow-occurring fishes were inactivated 28 to 64% more than predicted from the summed effects of denaturation by 1,000 atm pressure and tryptic inactivation at atmospheric pressure. In contrast, the homologues of the deep-sea species were inactivated by trypsin 0 to 21% more than expected. At 1,000 atm, inactivation by subtilisin increased to a similar degree for enzymes from both deep- and shallow-living species. However, at 1,000 atm, the M4-LDH homologues of the deep-sea species lost less activity (55.3%) than did the homologues of the shallow species (86.4%). In comparisons made at 200 atm, a pressure typical of the habitat of the deep-occurring species, tryptic inactivation of the LDH of the shallow-living Sebastes melanops was increased 14%. No pressure inactivation of the enzyme is evident at 200 atm.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pressure-adaptive differences in proteolytic inactivation of M4-lactate dehydrogenase homologues from marine fishes. 354 68

Three human cell lines from adenocarcinomas of the extrahepatic biliary tract were established in permanent tissue culture. Mz-ChA-1 and Mz-ChA-2 were cultured from mechanically dissociated gallbladder adenocarcinoma metastases and SK-ChA-1 was grown from malignant ascites of a patient with primary adenocarcinoma of the extrahepatic biliary tree. Cell doubling times in tissue culture are 3-4 days for Mz-ChA-1 and approximately 2 days for Mz-ChA-2 and SK-ChA-1. All three tumour cell lines were successfully transplanted to nude mice, inducing progressive tumour growth. Histologically, nude mouse tumours resembled the original adenocarcinomas. In vitro formation of gland-like structures were regularly seen in Mz-ChA-1 and Mz-ChA-2 but only occasionally in SK-ChA-1. All three cell lines formed contacts through interdigitating processes with desmosomes and junctional complexes. On scanning electron microscopy, an abundance of microvilli was seen at the cell surfaces. Chromosome analyses of all three tumour cell lines showed a wide range of numerical abnormalities and presence of marker chromosomes. Mz-ChA-1 appears to be highly differentiated with cells producing mucus. Mz-ChA-2 synthesizes components of complement C2, C3 and C5, while Mz-ChA-1 and SK-ChA-1 produce only C3 in detectable quantities. In addition, Mz-ChA-2 supernatants are positive for ferritin and alpha 1-fetoprotein, but not CEA; while Mz-ChA-1 and SK-ChA-1 produce only CEA. Supernatants of all three cell lines are positive for N-acetyl neuraminic acid (NANA), phosphohexoisomerase (PHI) and LDH, and negative for alpha 2-macroglobulin, alpha 1-anti-trypsin, gamma-GT, AP, coeruloplasmin, haptoglobin and albumin. A high cloning efficiency renders these new tumour cell lines suitable for continued studies on clonal heterogeneity in malignant tumours. The establishment of these cell lines in tissue culture facilitates further studies on the biology of upper gastrointestinal tract cancer in man.
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PMID:Biliary adenocarcinoma. Characterisation of three new human tumor cell lines. 405 57

Carboxymethylated sperm-specific lactate dehydrogenase isozyme C4 (LDH-C4) proteins from mouse and rat testes were cleaved with cyanogen bromide and trypsin. Proteins were also citraconylated and digested with trypsin. In the case of mouse LDH-C4 isozyme, all 7 CNBr and 11 limited tryptic (arginine) peptides were isolated and sequenced. Some of the CNBr peptides were further fragmented with trypsin and chymotrypsin and their compositions and/or sequences characterized. Also, 34 of the 36 expected tryptic peptides were purified, and their compositions and sequences determined. Amino acid sequences of these peptides purified from mouse LDH-C4 were overlapped into a complete covalent structure of the 330 residues. For rat LDH-C4, 5 of 6 expected CNBr peptides, 5 of 8 expected arginine peptides, and 28 of the 34 expected tryptic peptides were isolated, and their compositions and sequences were determined. Some of the CNBr and arginine peptides were further fragmented with chymotrypsin, thermolysin, or V8 protease, and their compositions and/or sequences characterized. The amino acid sequence of 85% of the 330 residues from rat LDH-C subunit has been unambiguously determined, and the sequences of the remaining regions were tentatively aligned on the basis of peptide compositions and sequence homologies with the other known lactate dehydrogenase sequences, including mouse LDH-C. A comparison of the proposed rat LDH-C sequence with the complete covalent structure of mouse LDH-C indicates that 27 differences are located in the established rat LDH-C sequence of 280 residues and that 5 additional differences are in the tentative sequence of the remaining 50 amino acids.
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PMID:Amino acid sequence studies on lactate dehydrogenase C4 isozymes from mouse and rat testes. 634 85

In order to evaluate whether structural differences exist between allelic variants of a B-type lactate dehydrogenase (LDH; L-lactate:NAD+ oxidoreductase, EC 1.1.1.27) in the minnow Fundulus heteroclitus, the allozymes (LDH-Ba4, LDH-Ba/Bb, and LDH-Bb4) were purified to homogeneity by affinity chromatography. Each variant was characterized as to holoenzyme and subunit molecular mass, isoelectric point (pI), thermal and urea stability, and susceptibility to proteolysis. Differences in electrophoretic mobilities were due to a lower pI for LDH-Ba4 (pI = 6.6) than for LDH-Bb4 (pI = 7.2). Stability to inactivation by heat, urea, and proteolysis was in each case: LDH-Bb4 greater than LDH-Ba/Bb greater than LDH-Ba4. Inactivation by trypsin may involve the arginine-rich catalytic loop of lactate dehydrogenase (50). The results suggest that the allozymes differ in their conformational flexibility.
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PMID:Purification and characterization of the lactate dehydrogenase (LDH-B4) allozymes of Fundulus heteroclitus. 669 86

Human chorio-amnion from term pregnancy was perfused in vitro in a dual perfusion apparatus. Renin released from the fetal membranes was almost entirely in the form of inactive renin (IR) (trypsin-activated). IR was released from both the chorion side and the amnion side. IR introduced on the chorion side of the chorio-amnion did not appear on the amnion side. When cells isolated from term amnion and chorion were grown in tissue culture, IR was released continuously from chorionic cells but not from amnionic cells. The release of IR did not parallel the release of LDH from cultured chorion cells. Exposure to low calcium medium (with or without EGTA) decreased IR release while LDH release increased (or remained constant). Exposure to the calcium ionophore (A 23187) resulted in a marked decrease in IR release. The release of IR from chorionic cells shows some similarities to the release of HCG from trophoblasts. It is expected that IR release from the chorion will show some similarities to R release from the kidney as well as major differences. The function, regulation, and processing of chorionic IR remain to be elucidated.
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PMID:Release of inactive renin from human fetal membranes and isolated trophoblasts. 675 76


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