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 amino acid sequence of phospholipase A2 from the venom of Trimeresurus flavoviridis (the Habu snake) was determined. The enzyme subunit has a molecular weight of 13,764 and consists of a single polypeptide chain of 122 amino acids and seven disulfide bonds. The fragmentation was conducted by digesting the reduced and S-carboxymethylated derivative of the protein with Achromobacter protease I, chymotrypsin, and trypsin, respectively. Achromobacter protease I peptides were used for alignment and to establish overlaps over chymotryptic and tryptic peptides. The automated Edman degradation of the S-carboxymethylated protein, which was extended to the N-terminal 30 amino acid residues, supplemented the deletions found with the enzymatic peptides alone. T. flavoviridis phospholipase A2 was found to be highly (65-67%) homologous in sequence to the enzymes from T. okinavensis, Crotalus adamanteus, and Crotalus atrox (viperid family) and less (35-44%) homologous to those from elapid snakes and mammalian pancreas. The T. flavoviridis enzyme appears to be similar in secondary structure composition to the C. atrox enzyme.
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PMID:Amino acid sequence of Trimeresurus flavoviridis phospholipase A2. 351 93

The factors causing a decline in renal perfusion were studied in anaesthetized dogs with acute pancreatitis 4 h after the forceful injection of bile into the pancreatic duct. In 11 such dogs, glomerular filtration rate (GFR) decreased by 40.4% from the control state (P less than 0.05), whereas the clearance of para-aminohippurate (CPAH) declined by 50.2%. These changes were associated with a 15.3% decline in cardiac output (P less than 0.05) and a 26.2% fall in plasma volume. Glomerular morphology was entirely normal. When hypovolemia was prevented by infusing homologous plasma over the 4-h period of observation, the normally observed decline in GFR, CPAH, and cardiac output was prevented. The decline in plasma volume, associated with a rising hematocrit and declining plasma protein concentration, and the associated decrement in renal perfusion, could be entirely duplicated by the infusion of trypsin, chymotrypsin, elastase, and phospholipase A2 (but not lipase or amylase) into normal dogs. These perturbations also were prevented by the concurrent infusion of 4% albumin in saline. At 24 h, however, the renal failure became unresponsive to volume replenishment. We conclude that the decline in renal perfusion in dogs at 4 h with acute pancreatitis is entirely due to hypovolemia, induced by the release of specific enzymes from the inflamed gland, which causes the loss of protein-rich plasma from the vascular space.
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PMID:Renal failure in dogs with experimental acute pancreatitis: role of hypovolemia. 378 59

Pancreatic amylase, elastase 1, elastase 2, cationic trypsin, chymotrypsin, ribonuclease (RNase), phospholipase A2, gamma-glutamyl transpeptidase (gamma-GTP) and pancreatic secretory trypsin inhibitor (PSTI) were purified and characterized from human pancreatic juice and pancreatic tissue. During the purification of these enzymes, two enzymes previously not reported were found. A pancreatic deamidase and a renal endopeptidase were purified and characterized. Specific and reliable radioimmunoassays (RIAs) were developed for all pancreatic enzymes and inhibitor. The purpose of immunoassay for pancreatic enzymes and inhibitor was discussed, and clinical application for the diagnosis of pancreatic diseases was demonstrated. Messenger RNA (mRNA) of amylase was isolated from human pancreas and parotid gland, and used to prepare a complementary DNA (cDNA). The nucleotide sequence and the predicted amino acid sequence of these clones were now being determined. The application of the present investigation to elucidation of pathogenesis of pancreatic enzyme-producing diseases was discussed.
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PMID:[Purification and development of immunoassay of pancreatic enzymes and trypsin inhibitor, and their application to elucidation of pathogenesis of various pancreatic and pancreatic enzyme-producing diseases]. 620 25

The effect of different enzymatic treatments on the specific binding of 3H-Etorphine to the membrane bound opiate receptors from human placenta was studied. Phospholipase A2 inhibited etorphine binding, suggesting either that phospholipids are essential for ligand binding or that products of the phospholipase A2 reaction, either lysophospholipids or fatty acids, disrupt the membrane integrity because of their detergent like properties. Trypsin and alpha-chymotrypsin had no effect, suggesting that the receptors binding site was not accessible to these proteolytic enzymes. We also find that the placental villus upon in vitro stimulation with potassium releases acetylcholine. The inhibitory effect of morphine on acetylcholine release was investigated.
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PMID:Biochemical and pharmacological studies on the opiate receptors from human placenta. 631 62

The complete amino acid sequence of phospholipase A2 (phosphatide 2-acylhydrolase, EC 3.1.1.4) from human pancreas was determined. The protein consists of a single polypeptide chain of 125 amino acids and has a molecular weight of 14003. The chain is cross-linked by seven disulfide bridges. The main fragmentation of the polypeptide chain was accomplished by digestion of the reduced and thialaminated derivative of the protein with clostripain, yielding three fragments. The largest fragment (residues 7-100) was further degraded both with staphylococcal proteinase and chymotrypsin. The sequence was determined by automated Edman degradation of the intact protein and of several large peptide fragments. Phospholipase A2 from human pancreas contains the same number of amino acids (125) as the enzyme from horse, while the enzymes from pig and ox contain 124 and 123 residues, respectively. The enzymes show a high degree of homology; human phospholipase differs from the other enzymes by substitutions of 26 (porcine), 28 (bovine) and 32 (equine) residues, respectively.
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PMID:The complete primary structure of phospholipase A2 from human pancreas. 634 96

Human brain and liver mitochondria contain membrane-bound monoamine oxidase of both A and B types. Monamine oxidase-A (MAO-A), either membrane-bound or in detergent-solubilized extracts from these tissues, was selectively inhibited during incubations with trypsin, chymotrypsin, thermolysin, or papain. MAO-A in solubilized, but not in membrane-bound, preparations was also very sensitive to the action of phospholipase A2, while MAO-B was unaffected. Membrane-bound MAO-A of rat brain mitochondria was more sensitive to phospholipases and less sensitive to proteases than was human brain enzyme, indicating that these agents may reveal species differences in MAO properties. Human brain and liver MAO-A, either solubilized or bound in mitochondrial membranes, apparently contains basic and aromatic peptide moieties that are available to proteases. Hydrolysis of these peptide bonds leads to rapid denaturation unless substrate molecules stabilize the active site. Phospholipase A2 may disrupt the phospholipid microenvironment of MAO-A, the integrity of which is essential for MAO-A activity, but not for MAO-B. No interconversion of the two activities was observed. After phospholipase A2 treatment, remaining MAO-A activity was recovered in low-molecular-weight regions of a gel filtration gradient, suggesting that MAO-A subunits were released. Although these experiments argue against the proposal that phospholipids may regulate the ratio of A/B activities of a single enzyme molecule, it is conceivable that endogenous phospholipases or proteases in mitochondrial membranes may influence MAO-A activity independently of MAO-B activity.
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PMID:Selective effects of proteases and phospholipase A2 on monoamine oxidases A and B of human brain and liver. 637 37

Agglutinability of red blood cells against anti-D increased remarkably when the cells were treated with proteolytic enzymes, such as bromelain, chymotrypsin, ficin, papain, pronase and trypsin. When stroma prepared from normal red blood cells was treated with any of proteolytic enzymes, however, Rh-Hr blood type activities were completely abolished. The similar results were obtained from stroma solubilized with detergents which was treated with enzymes after being prepared. Of all the enzymes, ficin acted more slowly than the others did. Neuraminidase or phospholipase A2 had no effect on Rh-Hr activities at all. SDS-polyacrylamide gel electrophoretic pattern of stroma prepared from bromelain, ficin and pronase-treated red blood cells were quite different from that of normal stroma.
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PMID:Rh0(D) activity of red blood cells and stroma treated with proteolytic enzymes. 643 38

Cationic lysosomal proteins from human polymorphonuclears (PMN) were isolated by column chromatography and divided into five fractions. On acrylamide gel electrophoresis, fraction I had four bands slower than lysozyme (LZM) mobility; fraction II had five or six bands slower than LZM; fraction III had at least seven bands slower and two bands faster than LZM; fraction IV contained LZM, two bands faster and a few faint bands slower than LZM; fraction V was composed of almost pure LZM. Partial characterization of the fractions showed presence of neutral protease in fractions I-IV, chymotrypsin in fraction III, lysozyme in fractions IV and V, and phospholipase A2 mainly in fractions II and III. Modulatory activity of fractions I-V were tested at concentrations up to 50 micrograms/ml. Enhancement of phagocytosis of Staphylococcus aureus was observed by fractions I, IV, and V, whereas phagocytic index was enhanced by all but the fraction II. Intracellular bactericidal activity (ICBA) was markedly enhanced by fractions I, II, and V. Addition of DNA or cytochalasine B inhibited or abolished phagocytosis-enhancing activity of cationic fractions. Their influence on ICBA was much less pronounced. Fraction III enhanced phagocytic index and phagocytosis of E. coli, whereas fractions I and II enhanced intracellular bactericidal activity against this bacteria. Enhancement of phagocytic activity of monocytes has also been observed. The data suggest that some cationic lysosomal fractions from human PMNs enhance phagocytosis and phagocytic index by human PMNs and monocytes and intracellular bactericidal activity of human PMNs. This alternative pathway of phagocytic enhancement is unrelated to the previously described enhancers of phagocytosis and may play a role in defense mechanisms against infection.
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PMID:Modulation of phagocytosis and intracellular bactericidal activity of polymorphonuclear and mononuclear cells by cationic proteins from human granulocytes: alternative pathway of phagocytic enhancement. 651 76

This study demonstrates that p-bromophenacyl bromide irreversibly inhibits, in a time- and dose-dependent manner, yeast alcohol dehydrogenase, bovine pancreatic alpha-chymotrypsin, human platelet phosphatidylinositol (PI)-specific phospholipase C, in addition to the neutral-active and calcium-dependent phospholipase A2 of human platelets. The PI-specific phospholipase C has maximal activity at pH 5,5 is calcium-dependent, and is strongly inhibited by sulfhydryl reagents 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and methylmethane thiosulfonate . Increasing concentrations of DTNB produced concomitant inhibition of phospholipase C activity and titration of sulfhydryl groups. In contrast, human platelet phospholipase A2 activity was unaffected by concentrations of DTNB that titrated sulfhydryl groups, and completely inhibited PI-specific phospholipase C activity. Treatment of cysteine with p-bromophenacyl bromide resulted in modification of the amino acid as demonstrated by paper chromatography, and loss of titratable sulfhydryl groups. These data show that p-bromophenacyl bromide inhibits a wide spectrum of enzymatic activities including PI-specific phospholipase C. This reagent modifies amino acid residues other than active-site histidines and therefore has a broader reactivity than previously considered. Thus, it should not be used as a selective inhibitor of enzymes in crude cellular experiments.
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PMID:Nonspecific inhibition of enzymes by p-bromophenacyl bromide. Inhibition of human platelet phospholipase C and modification of sulfhydryl groups. 673 33

1. The effect of various proteolytic enzymes was assayed on the adenylate cyclase activity in purified brain membrane preparations from the insect Ceratitis capitata. Trypsin, chymotrypsin, papain, thermolysin, elastase, subtilisin and prot. XIV were examined. 2. Trypsin treatment, at 37 degrees C, decreased the adenylate cyclase activity even in the presence of GppNHp that protects the activity from the thermal inactivation. 3. Residual basal, GppNHp- and F(-)-stimulated activities were similar when membrane preparations were preincubated either in the presence or in the absence of GppNHp and F-. 4. All proteolytic activities assayed on the brain membrane preparations, excepting papain, exerted an inhibition of adenylate cyclase in basal conditions. 5. The inhibition was stronger in the presence of F- than in the presence of other regulators. 6. Papain showed also a notable inhibition of adenylate cyclase in the presence of F-. 7. Phospholipase A2 treatment decreased both basal and stimulated activity; however, F(-)-sensitive activity was less affected than basal and GppNHp-sensitive activity. F(-)-stimulated activity was less affected by phospholipase A2 than either basal or GppNHp-stimulated activities. 8. Phospholipids are, then, essential for the highest basal activity, although the relationship between catalytic and nucleotide-regulatory components was unaffected by this treatment.
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PMID:Effect of proteolytic and lipolytic enzymes on the adenylate cyclase activity from brain membranes of Ceratitis capitata. 675 15


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