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)

Antibody-mediated spermagglutination is responsible for infertility in some couples and fertilization in vitro can also be impaired by these antibodies. Having previously demonstrated the possibility of enzymatic disagglutination in such situations, the functional potential of disagglutinated spermatozoa has now been assessed. Chymotrypsin (500 U/ml) and papain (50 U/ml) resulted in impairment of oocyte penetration in the zona-free hamster egg penetration test. Trypsin (500 U/ml), while having no effect on egg penetration of normal spermatozoa, significantly improved oocyte penetration of spermatozoa which had been previously incubated with spermagglutinating antibody-positive sera. Sperm-mucus interaction was not improved, however, by trypsin treatment of agglutinated spermatozoa. This technique may be of value in conjunction with in-vitro fertilization in situations where spermagglutination exists, and also possibly with intra-uterine insemination if improved fertilizing ability can be confirmed in vitro.
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PMID:Treatment of spermagglutination with proteolytic enzymes. II. Sperm function after enzymatic disagglutination. 218 63

Serine proteinases have the potential to influence the degradation of connective tissue in chronic periodontitis, which may progress episodically at individual tooth sites. Elastase-, chymotrypsin- and tryptase-like proteinase activity in homogenized gingival tissue were measured using, respectively, the selective peptide substrates MeOSuc-Ala-Ala-Pro-Val-AFC. MeOSuc-Phe-Pro-Phe-AFC and Z-Ala-Arg-Arg-AFC. Each tooth site was assayed separately and divided, where appropriate, into gingival tissue and granulomata. Elastase-like activity was detected in only about half of the sites and with large variations. Chymotrypsin-like activity decreased with increasing pocket depth, clinical attachment level, gingival index and gingival bleeding index. Tryptase-like activity did not vary consistently with clinical measures. Chymotrypsin- and tryptase-like proteinase activity were much higher in gingival tissue than in granulomata. These effects are best explained by the likely influence (or lack of influence) of the endogenous serum and tissue inhibitors of serine proteinases, the different cellular origins of the enzymes, and their relative affinities for their substrates.
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PMID:A biochemical study of serine proteinase activities at local gingival tissue sites in human chronic periodontitis. 220 77

In Ciona intestinalis, sperm penetration through the egg vitelline coat is an essential event of fertilization. We investigated whether trypsin- and chymotrypsin-like enzymes are involved in this event. Inhibitors and peptide substrates for chymotrypsin-like enzymes blocked the overall process of fertilization in a concentration-dependent manner. The inhibitory activity was specifically exerted on the step of sperm penetration. Chymotrypsin-like protease activity was identified in spermatozoa with the fluorogenic synthetic substrate Suc-Ala-Ala-Phe-AMC, which was the most effective substrate in blocking sperm penetration. These data indicate that a chymotrypsin-like protease activity is a sperm lysin of Ciona intestinalis.
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PMID:Chymotrypsin-like enzymes are involved in sperm penetration through the vitelline coat of Ciona intestinalis egg. 222 80

The susceptibility of the progesterone receptor, liganded either by the antiprogestin RU 486 or by the progestin ORG 2058, to chymotrypsin and trypsin degradation was investigated. The nuclear fraction was isolated from T47D cells previously exposed either to 0.1 microM [3H]RU 486 or to 0.1 microM [3H]ORG 2058. The proteolytic digestion was performed on the micrococcal nuclease hydrolysate. The molecular weights of the receptor fragments were calculated, in high salt buffer, from the sedimentation coefficients determined on a sucrose gradient and from the Stokes radii estimated by gel filtration on an Agarose A-0.5 m column. Micrococcal nuclease solubilized receptor forms with molecular weights of 80,000 and 75,000 for the antiprogestin- or progestin-liganded receptor, respectively. Chymotrypsin degraded these receptor forms to fragments with molecular weights of 23,000 either for the antiprogestin- or progestin-liganded receptor. Similar molecular weights of 23,000 were calculated for the progesterone receptor liganded either by the antiprogestin RU 436 or the progestin ORG 2058 following trypsin cleavage. We conclude that the degradation pattern of the progesterone receptor liganded either by the antiprogestin RU 486 or the progestin ORG 2058 following chymotrypsin or trypsin digestion seems to be similar.
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PMID:Comparison of the physical properties of the nuclear progesterone receptor, bound to antiprogestin RU 486 or progestin ORG 2058, following limited proteolysis. 238 53

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

Trp repressor of Escherichia coli K-12 is a dimeric protein (monomer size, 108 amino acids) that acquires high affinity for certain operator targets in double-stranded DNA upon interaction with L-tryptophan. High titer antiserum directed against E. coli Trp repressor protein, elicited in rabbits, was monospecific toward native or denatured Trp repressor. Using an enzyme-linked immunosorbent assay to measure antigen-antibody reaction, we found that the binding of L-tryptophan to Trp repressor was associated with a marked decrease in antibody reactivity that presumably accompanied a conformational change in this protein to a state with strong affinity for trp operator-bearing DNA. We analyzed the pattern of cleavage of Trp repressor by chymotrypsin and trypsin and the effect of L-tryptophan on such hydrolytic cleavages. Chymotrypsin cleaved Trp repressor mainly between residues 71 and 72. In the presence of L-tryptophan this cleavage was slowed. The first-order rate constants for chymotryptic digestion of Trp repressor were 7.6 X 10(-2) and 4.6 X 10(-2) min-1 in the absence and presence of L-tryptophan, respectively. Tryptic digestion was more complex. Initial cleavage of Trp repressor occurred with approximately equal facility between residues 69-70 or 84-85. Subsequent tryptic hydrolyses led eventually to a major core fragment containing the first 54 amino acids of Trp repressor plus four other fragments from the carboxyl-terminal half of the protein. In the presence of L-tryptophan, cleavage by trypsin between residues 54-55 and 84-85 was retarded, even when a previous hydrolytic event elsewhere in the protein had occurred. Tryptophan had essentially no effect on the tryptic hydrolysis of peptide bond 97-98, but accelerated cleavage at peptide bond 69-70. The first-order rate constants for the first tryptic cleavage of Trp receptor were 1.55 X 10(-1) and 1.33 X 10(-1) min-1 in the absence and presence of ligand, respectively. Our results are compatible with a structural model wherein certain amino acid side chains and peptide bonds of Trp repressor (specifically, those of residues 69-85) lie on or near the surface of the protein. This region of Trp repressor has been predicted to contain the operator recognition site. The susceptibility to proteolytic attack of at least four peptide bonds in this area changes when the protein interacts with L-tryptophan.
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PMID:Ligand-mediated conformational changes in Trp repressor protein of Escherichia coli probed through limited proteolysis and the use of specific antibodies. 241 31

In inside-out red cell membrane vesicles active calcium transport and the formation of the enzyme-phosphate complex (EP) of the calcium pump were simultaneously investigated and the effects of a limited proteolytic digestion examined. In order to visualize the proteolyzed EP forms we have induced the formation of a maximum level EP from [gamma-32P]ATP in the presence of Ca2+ + La3+ and applied a good-resolution acidic discontinuous sodium dodecyl sulfate-polyacrylamide gel electrophoresis system. Proteolysis of inside-out vesicle membranes by trypsin, Pronase, papain, or chymotrypsin produces a calmodulin-like activation of the calcium pump, abolishes its calmodulin sensitivity, and decreases the original 140-kDa EP complex to a limit polypeptide of 80 kDa. Trypsin digestion produces another major intermediary fragment of 90 kDa, which is still a low-activity calmodulin-sensitive form of the pump. The red cell calcium pump is activated by trypsin both in the absence and presence of Ca2+ during digestion although the rate of activation and the appearance of the 80-kDa polypeptide are enhanced by Ca2+. If proteolytic digestion is carried out by chymotrypsin, a calmodulin-insensitive maximum activation of the calcium pump coincides with the formation of a 125-130-kDa EP-forming polypeptide. Chymotrypsin and carboxypeptidase A have synergistic effects on the formation of this latter high-activity species. Based on these data we suggest a probable molecular arrangement for the functional parts of the red cell membrane calcium pump.
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PMID:Molecular characterization of the in situ red cell membrane calcium pump by limited proteolysis. 242 14

Porcine pancreatic hydrolases in juice and homogenate surveyed by electrophoretic separation in agarose gel, at pH 8.6 and subsequently characterized using substrates of various specificity, either directly in the gel or after transfer to nitrocellulose (enzymoblotting) showed: Anodal and cathodal trypsin with Bz-Arg-pNA. Chymotrypsin A, B, and C with similar, but not identical, activities to Suc-Ala-Ala-Pro-Phe-pNA, Bz-Tyr-pNA, Suc-Phe-pNA and Ac-Phe-beta NE and with differences in their molecular weights and electrophoretical charges. Elastase I and protease E with Suc-(Ala)3-pNA and MeO-Suc-Ala-Ala-Pro-Val-pNA and elastase I also with elastin. Elastase II with the chymotrypsin substrates and with elastin. Carboxypeptidase A with CN-Phe. Amylase with blue starch polymer.
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PMID:Identification and characterization of eight porcine pancreatic proteinases, carboxypeptidase A and amylase after electrophoretic separation using specific substrates. 244 43

This paper experimentally verifies the idea presented earlier that the contact of nonpolar clusters located on the surface of protein molecules with water destabilizes proteins. It is demonstrated that protein stabilization can be achieved by artificial hydrophilization of the surface area of protein globules by chemical modification. Two experimental systems are studied for the verification of the hydrophilization approach. The surface tyrosine residues of trypsin are transformed to aminotyrosines using a two-step modification procedure: nitration by tetranitromethane followed by reduction with sodium dithionite. The modified enzyme is much more stable against irreversible thermoinactivation: the stabilizing effect increases with the number of aminotyrosine residues in trypsin and the modified enzyme can become even 100 times more stable than the native one. Alpha-chymotrypsin is covalently modified by treatment with anhydrides or chloroanhydrides of aromatic carboxylic acids. As a result, different numbers of additional carboxylic groups (up to five depending on the structure of the modifying reagent) are introduced into each Lys residue modified. Acylation of all available amino groups of alpha-chymotrypsin by cyclic anhydrides of pyromellitic and mellitic acids results in a substantial hydrophilization of the protein as estimated by partitioning in an aqueous Ficoll-400/Dextran-70 biphasic system. These modified enzyme preparations are extremely stable against irreversible thermal inactivation at elevated temperatures (65-98 degrees C); their thermostability is practically equal to the stability of proteolytic enzymes from extremely thermophilic bacteria, the most stable proteinases known to date.
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PMID:Protein stabilization via hydrophilization. Covalent modification of trypsin and alpha-chymotrypsin. 245 6

The inhibition of six serine proteinases by a tumour-associated trypsin inhibitor (TATI) was studied using synthetic peptide substrates. Physiological concentrations of TATI inhibited the amidolytic activities of trypsin, plasmin, urokinase and tissue plasminogen activator (tPA). Chymotrypsin, kallikrein and thrombin were also inhibited, but by much higher concentrations of TATI. The ability of TATI to inhibit trypsin, plasmin, urokinase and tPA suggests that it has a role in proteolytic processes in vivo involving these enzymes.
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PMID:Reaction of a tumour-associated trypsin inhibitor with serine proteinases associated with coagulation and tumour invasion. 246 2


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