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 authors report the effects of four proteases (trypsin, plasmin, chymotrypsin and thrombin) on human heart adenylate cyclase (HHAC) activity. Trypsin and plasmin inhibited HHAC at concentrations higher than 0.3 and 1 microgram/ml, respectively. Chymotrypsin had a biphasic effect, with a stimulation (from 0.5 to 10 micrograms/ml) followed by an inhibition at higher concentrations. Maximal stimulation was obtained at 3 micrograms/ml and averaged 67.2 +/- 5.4%. Thrombin had no significant effect at concentrations up to 1 mg/ml. These data indicate that proteases might regulate HHAC and therefore influence cardiac function.
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PMID:The effects of trypsin, plasmin, chymotrypsin and thrombin on human heart adenylate cyclase activity. 295 13

Hydrolysis of histones by proteinases from rat liver, skin and other sources was studied by using a rat thymus histone preparation as the substrate and polyacrylamide-gel electrophoresis and densitometric analysis as the methods to detect histone subtypes and their hydrolysis. The rat mast-cell proteinase I effectively hydrolysed histones except type H4. Thrombin hydrolysed effectively histones H1 and H2A, whereas plasmin hydrolysed all types of histones. Cathepsin D hydrolysed especially histone H2A. Cathepsins B and L hydrolysed all histones more slowly, and cathepsin H hydrolysed them extremely slowly. Epidermal aminoendopeptidase did not hydrolyse histones. Trypsin and chymotrypsin were used as reference enzymes, which hydrolysed all types of histones in very low concentrations. This study suggests that a variety of proteinases could play a role in histone hydrolysis. Hydrolysis of a specific subtype of histones, such as histone H2A at pH 6 by cathepsin D, may be directly involved in regulation of epidermal-cell differentiation.
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PMID:Hydrolysis of histones by proteinases. 296 88

One hundred nineteen children, either French or from the Ivory Coast, aged 1-8 years, were submitted to pancreatic function testing by duodenal aspiration. Trypsin, chymotrypsin, lipase, phospholipase, amylase, volume, bicarbonate, chloride, and calcium were estimated before and after an intravenous injection of 1 CU secretin + 3 CHR units pancreozymin per kilogram of body weight. Sixty-two patients were normal European children, and 11 were normal African children. Twenty-five African children presented with kwashiorkor and 10 African children had presented with kwashiorkor but had recovered at the time of the test. Three cases of recurrent kwashiorkor are also included. In the normal group of African children, phospholipase concentration, volume, and bicarbonate were significantly decreased but chymotrypsin and trypsin concentrations were not, when compared to the normal European population. In kwashiorkor patients, lipase, amylase, phospholipase, and chymotrypsin concentration were significantly decreased compared to normal Africans. Trypsin, volume, and bicarbonate were not affected. These modifications disappeared after refeeding. In cases of recurrent kwashiorkor, all enzymes, including trypsin, were decreased. Calcium was never modified. These modifications were very different from those observed in chronic alcoholic and hypercalcemic pancreatitis. In a two-year study, chronic calcifying pancreatitis (CCP) was diagnosed in 14 patients (13 males), hospitalized in Abidjan. The mean age at onset of the disease was 41 years (SD 12.71), which is very similar to European cases. The most frequent cause was alcoholism, as in Occidental countries. The nutrition of the population was low in protein, calories being provided mostly by manioc, but no apparent symptoms of malnutrition were observed in the parents of our patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Exocrine pancreatic function of children from the Ivory Coast compared to French children. Effect of kwashiorkor. 300 10

Trypsin and chymotrypsin inactivated specific [3H]yohimbine binding sites in the partially purified human platelet membranes in a concentration- and time-dependent fashion. The maximal inactivation (70-80% of control) was incomplete regardless of the concentrations of the proteases used or the incubation time. Scatchard analysis of the binding data showed that the total number of binding sites was reduced, but the affinity of the receptor to the ligand remained unaffected. Pretreatment of the membranes with unlabeled yohimbine or epinephrine produced a 20-30% increase in the specific [3H]yohimbine binding; however, this treatment offered only a slight protection (10-15%) against trypsin-induced inactivation of [3H]yohimbine binding. Pretreatment with phospholipase A2 produced a complete inhibition, while pretreatment with phospholipase C resulted in only a partial (70-80% of control) reduction in [3H]yohimbine binding. The inhibitory effects were not reversed when the specific binding of [3H]yohimbine was carried out with membranes treated with phospholipases and subsequently washed with defatted bovine serum albumin, suggesting that products released from phospholipolysis were not involved in the inhibition of [3H]yohimbine binding. These results suggest that the integrity of the receptor proteins and phospholipids is necessary for the specific binding of the ligand to the alpha 2-adrenoreceptor proteins of the human platelet membranes.
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PMID:Effect of proteases and phospholipases on [3H]yohimbine binding to human platelet membranes. 301 56

The pharmacokinetic interaction of an affinity-purified 125I-labeled tetanotoxin fraction with guinea pig brain synaptosomal preparations was investigated. Binding of tetanotoxin was time- and temperature-dependent, was proportional to protein concentration, and was saturable at about 8 X 10(-9) M as estimated by a solid-surface binding assay. Binding was optimal at pH 6.5 under low ionic strength buffer and was almost entirely blocked by gangliosides or antitoxin. In analogy to intact nerve cells, binding of toxin to membranes resulted in a tight association operationally defined as sequestration. Binding and sequestration were abolished after membrane pretreatment with sialidase. The enzyme could not dissociate the membrane-bound toxin formed at 4 or 37 degrees C under low ionic strength conditions, which is in part compatible with internalization as defined in nerve cell cultures. In the latter system the toxin could be removed at 4 degrees C but not at 37 degrees C. Binding was significantly reduced upon pretreatment of guinea pig brain membranes by a variety of hydrolytic enzymes. Trypsin and chymotrypsin inhibited binding between 55% and 68% while bacterial protease abolished it by 91-95%. The effect was species-specific as it was not seen in rat or bovine synaptosomes. Collagenase and hyaluronidase had little or no inhibitory effect when applied to synaptosomes (27% and 9%) but inhibited binding to synaptic vesicles by 56% and 49%, respectively. Phospholipases A2 and C caused 42-43% inhibition of binding in vesicles and less than 22% in synaptosomes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Affinity-purified tetanus neurotoxin interaction with synaptic membranes: properties of a protease-sensitive receptor component. 302 42

Trypsin cleaves the fusion protein (F) of wild-type Sendai virus into two disulfide-linked polypeptides, F1 and F2, and thereby activates the membrane fusion activity of the virus. A. Scheid and P.W. Choppin [1976). Virology, 265-277) selected mutant viruses of which the F protein could be activated by different proteases, either elastase, chymotrypsin, or plasmin. Herein, we have further characterized five of these mutants. Sequencing of each mutant mRNA encoding the 60-70 amino acids surrounding the cleavage site revealed one or two amino acid changes near or at the cleavage sites. Virions cleaved in vitro by the appropriate proteases were assayed of their fusion activity by hemolysis, and the cleavage sites were determined by amino acid sequencing. In three cases, the change of protease specificity can be accounted for by changed amino acids right at the cleavage site, whereas several other mutations that potentiate cleavage at new sites by new proteases are somewhat removed from the actual cleavage site. We surmise that such mutations might alter local polypeptide conformation, thereby allowing the proteases access to existing sites. Cleavage at new sites produced fusion proteins with novel F1 NH-termini. We found that a mutant with a charged residue at the third position of this normally hydrophobic NH-terminal sequence retains activity in the hemolysis assay, whereas a mutant with a charged residue at the first position does not.
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PMID:Protease activation mutants of Sendai virus: sequence analysis of the mRNA of the fusion protein (F) gene and direct identification of the cleavage-activation site. 302 71

Digestion of the rat liver glucocorticoid receptor with chymotrypsin results in the generation of a 42-kDa fragment which contains the steroid-binding and DNA-binding domains and the antigenic site for the BuGR anti-glucocorticoid receptor monoclonal antibody, while digestion with trypsin generates a 15-kDa receptor fragment containing only the DNA-binding function and the BuGR epitope (Eisen, L.P., Reichman, M.E., Thompson, E.B., Gametchu, B., Harrison, R. W., and Eisen, H.J. (1985) J. Biol. Chem. 260, 11805-11810). In this paper, glucocorticoid receptor of mouse L cells that were grown in the presence of [32P]orthophosphate was digested with trypsin or chymotrypsin (either before or after immune purification with BuGR antibody) and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, autoradiography, and Western blotting. The receptor is endogenously phosphorylated only on serine residues. Chymotrypsin digestion results in a 32P-labeled 42-kDa receptor fragment which contains steroid-binding, DNA-binding, and BuGR-reactive sites. Trypsin digestion generates a 27-kDa steroid-bound fragment (meroreceptor) which is not labeled with 32P and a 32P-labeled 15-kDa fragment which contains both the DNA-binding domain and the BuGR epitope. We have calculated that there are 4 times as many phosphate residues in the intact receptor than in the 42-kDa chymotrypsin fragment. From examination of 32P-labeled receptor fragments, we have deduced that one phosphate is located between amino acids 398 and 447, a region containing the BuGR epitope and about one-third of the DNA-binding domain, and the remaining three phosphates appear to be clustered just to the amino-terminal side of the BuGR epitope in a region defined by amino acids 313 to 369. Treatment of intact 32P-labeled receptor in cytosol with alkaline phosphatase removes these three phosphates, but it does not remove the phosphate from the DNA-binding-BuGR-reactive fragment and it does not affect the ability of the transformed receptor to bind to DNA-cellulose.
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PMID:Localization of phosphorylation sites with respect to the functional domains of the mouse L cell glucocorticoid receptor. 304 15

Recent data on the nature of trypsin-, chymotrypsin-like proteinases of fish are generalized. Localization and secretion of these enzymes in pyloric appendages of fish are considered in detail. Trypsin and chymotrypsin are in the state of proenzymes and transform into the active form by means of their own proteolytic factors. It is observed that the classical methods for isolation of individual chymotrypsin and trypsin cannot be used in the case of fish, since the fish enzymes are stable in the neutral and low-alkaline media and unstable in the acid medium. This is, first of all, accounted for by differences in the physicochemical characteristics of the test enzymes. New data on the biospecific chromatography of serine proteinases of lower invertebrates are presented. Biospecific sorbents used for isolating enzymes from mammals are not always convenient for purification of fish serine proteinases. This evidences for considerable differences in their active sites and, probably, in their binding sites, whose nature is responsible for the specificity and is important for the selective chromatography of enzymes.
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PMID:[Trypsin-, chymotrypsin-like proteinases in fishes]. 305 78

The bioactive substance from rat's vessel wall was purified by Sephadex G-75 gel filtration and by a combination of DEAE Cellulose ion exchange and Sephadex G-50 gel filtration chromatographies. Purifications of 12.5 fold and 70 fold over the initial material were achieved. PAGE of the purified material resulted in a single major band with a molecular weight estimated at 55kd-65kd. Trypsin (0.3 mg/ml) and chymotrypsin (30 mg/ml) abolished platelet antiaggregating activity. Neuraminidase (1.2 units) had no effect on platelet antiaggregating activity. This is the report of purification of aortic vessel wall antiaggregating activity independent of prostacyclin production.
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PMID:Purification and partial characterization of a bioactive substance from rat's vessel wall independent of prostacyclin production. 305 78

Effects of blood serum on u-PA (EC 3.4.21.31) fibrinolytic activity were studied. After incubation for one hour at 37 degrees of the enzyme with human blood serum (55-145 IU/ml of blood serum) the enzymatic activity was completely inhibited. At the same time, amido-lytic activity of u-PA, estimated with low molecular substance S2444 as a substrate, was maintained in presence of blood serum. Blood serum inhibitors did not exhibit the specific affinity to u-PA. Serine proteases (trypsin, chymotrypsin and plasmin) competed with u-PA at equimolar concentrations. These inhibitors were inactivated after blood serum preincubation with primary amines methylamine, ethylamine, putrescine, spermidine and spermine (0.1-10 mM). The u-PA-inhibitor complexes were not dissociated in presence of 2.5 mM sodium dodecylsulfate. Trypsin-albumin copolymer bound specifically the blood serum u-PA inhibitors and the fraction adsorbed was electrophoretically characterized as a protein with molecular mass of 185 kDa.
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PMID:[Interaction of plasminogen activator of urokinase type with human serum]. 314 85


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