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)

Preparations of ECF-A derived from anaphylactic guinea-pig lung diffusates were subjected to a variety of enzymatic degradations. The enzymes employed had specificityonly for their appropiate subtstates. No effect was found following treatmentwith relatively high doses of trypsin, alpha-chymotrypsin, pronase, alkaline phosphataseand sialidase. In contrast a loss of activity was demonstated in a dose-dependent fashion following incubation with tyrosinase, aryl sulphatase and leucine aminopeptidase, suggesting that ECF-A contains a phenolic hydroxyl group, a sulphate ester anda peptide linkage with a free alpha-amino group.
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PMID:The effect of enzyme digestions on the activity of eosinophil chemotactic factor of anaphylaxis (EFC-A). 80 20

Immunoblotting with two examples of anti-Dha to the electrophoretically separated components of antigen-positive membranes gave a positive reaction with a component of the same apparent Mr (40,000) as sialoglycoprotein beta (SGP beta, syn: glycoconnectin, glycophorin C). The Dha antigenic determinant was sensitive to trypsin, but resistant to chymotrypsin and Endo F. By immunoblotting, one anti-Dha failed to react with sialidase-treated Dh(a+) cells, whilst the other gave a positive result. In contrast, neither antibody agglutinated sialidase-treated red cells. SGP beta was precipitated from Dh(a+) and Dh(a-) phenotype red cells by monoclonal anti-beta (NBTS/BRIC 10). SGP beta from Dh(a+) but not from Dh(a-) red cells was stained by immunoblotting with anti-Dha. These results assign the Dha antigenic epitope to SGP beta.
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PMID:Immunochemical characterisation of the low-incidence antigen, Dha. 171 1

Human anti-S and anti-s eluates bound to glycophorin B on immunoblots from membranes of S+ and s+ red cells, respectively. Eluates of human anti-S were more efficiently prepared from sensitized trypsin-treated cells than from sensitized untreated cells. The results of immunoblotting membranes from enzyme-treated cells confirmed the serological findings: S and s antigens were not affected by treatment with trypsin or sialidase but were destroyed or much depressed by treatment with papain, pronase or alpha-chymotrypsin. Immunoblotting with anti-S or anti-s of membranes from cells with unusual MNS phenotypes confirms the involvement of glycophorin B in hybrid glycophorins; the existence of such hybrid glycophorins was deduced previously from serological work or immunoblotting with monoclonal antibodies. The presence of s-active glycophorin B in glycophorin (B-A)Dantu, in glycophorin BMiIII and in glycophorin (A-B)MiV was confirmed. The bands observed when Mit+ membranes were immunoblotted with anti-S supports the suggestion from serological work that the Mit antigen is associated with an altered S antigen.
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PMID:Immunoblotting of human red cell membranes: detection of glycophorin B with anti-S and anti-s antibodies. 239 72

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

Human-type blood group activities on the red blood cells (RBCs) of three chimpanzees were individually examined with commercial mouse monoclonal antibodies (anti-A, -B, -H, -M, -N, -Lea, and -Leb) as well as lectins (UEA-I and VGA) and conventional polyclonal antisera for the systems ABO, MN, Lewis, Rh-Hr, P, Kell, Kidd, Duffy, and Lutheran. For further analysis of the MN antigens, treatment of the RBCs with sialidase, trypsin, and chymotrypsin were employed. The activities recognized among the three chimpanzees were A, H, M, N, Leb, c, S, k, and Jka. The RBCs of the three individuals possessed the A antigen which showed the same serologic activity as the human A1. Those chimpanzee RBCs showed higher H-activity than the human A1 RBCs. The Lewis b activity was revealed by the absorption-elution method. The RBCs of the three individuals showed a reactivity to the polyclonal anti-M reagents, which was affected by both the sialidase and trypsin treatment. The RBCs of two individuals were agglutinated with the monoclonal anti-N. The receptor was sensitive to sialidase and chymotrypsin. The RBCs of the three individuals, however, did not react with the monoclonal anti-M or with one of the polyclonal anti-N. These results indicate structural differences in the glycophorins and MN antigens between the human and chimpanzee.
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PMID:Human-type blood group activities on chimpanzee erythrocytes with special reference to M and N. 323 60

Kidney allograft rejection is an inflammatory process dominated by lymphocytes. During rejection lymphocytes preferentially adhere to the peritubular capillary endothelium (PTCE), which acquires morphological features common to high endothelium. These observations indicate that PTCE is the site of lymphocyte entry into the rejecting renal allograft. Of the identified endothelial adhesion molecules, ICAM-1 was already expressed on the endothelium of normal kidneys, and its expression was strongly enhanced during rejection without site-specific restriction. VCAM-1 was not expressed on the endothelium of normal or syngeneic kidneys, but its expression was induced during allograft rejection not only in PTCE, but occasionally also on the endothelium of larger vessels. Sialyl Lewisx (sLex) showed a very restricted pattern of expression; endothelium was sLex-negative both in control and syngeneic kidneys. On the other hand, PTCE reacted strongly with anti-sLex antibody in allografts. When kidney frozen sections were treated with sialidase the binding of lymphocytes decreased by 70%. Low-dose chymotrypsin treatment of lymphocytes, known to remove L-selectin from the lymphocyte surface, decreased their binding to PTCE by 60%. Likewise lymphocyte adhesion to PTCE was inhibited by 70% by anti-sLex- and anti-L-selectin-antibodies and by sLex tetrasaccharide. Finally PTCE in the allografts, but not in syngeneic grafts or normal kidneys, bound an L-selectin-IgG fusion protein, indicating that ligands for L-selectin were induced during rejection.
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PMID:Sialyl Lewis(x)- and L-selectin-dependent site-specific lymphocyte extravasation into renal transplants during acute rejection. 751 29

Conversion of factor X to factor Xa results in release of a heavily glycosylated activation peptide. Analysis of protease-digested glycopeptides derived from the activation peptides of bovine and human blood coagulation factor X allowed the identification of sites of the O-linked oligosaccharide chains in these peptides. Glycopeptides were prepared from the activation peptides by digestion with chymotrypsin or Staphylococcus aureus V8 protease. By combined analysis of amino acid sequence and sialic acid content, we found that bovine factor X had an O-linked oligosaccharide chain linked to Thr26, and human factor X had four carbohydrate-attachment sites, namely, O-glycosidic linkages to Thr17 and Thr29, respectively, and N-glycosidic linkages to Asn39 and Asn49, respectively, in their activation peptides. The O-linked carbohydrate-attachment sites were identified since the yields of phenylthiohydantoin derivatives of amino acids that corresponded to their residues were increased during amino acid sequencing after deglycosylation of the glycopeptides with sialidase and O-glycanase. The effect of deglycosylation of bovine factor X1 was investigated with factor-X-activating enzyme from Russell's viper venom or extrinsic Xase (factor VIIa/tissue factor/phospholipid) by examining the activation rates of derivatives of factor X prepared using O-glycanase, sialidase, and/or N-glycanase. The removal of O-linked carbohydrate resulted in a decrease in the rate of activation. It appears that carbohydrate residues in factor X play an important role in the activation of the zymogen.
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PMID:Identification of O-linked oligosaccharide chains in the activation peptides of blood coagulation factor X. The role of the carbohydrate moieties in the activation of factor X. 824 61

The influence of charged groups in glycoproteins was investigated to assess their effect on the physiological functions of bonnet monkey cervical mucus. The macromolecular glycoproteins from peri-ovulatory, midcycle phase cervical mucus were treated with Pronase, trypsin and chymotrypsin and the enzyme-resistant glycoproteins purified by gel filtration on Sepharose 4B and a high molecular weight component containing carbohydrates, proteins and sulfate groups was recovered in high yield. This material still reacted with an antiserum directed against purified midcycle glycoprotein but not against another antiserum directed against luteal phase purified glycoproteins. Upon treatment with Pronase, trypsin and chymotrypsin, asialoglycoproteins and desulfated asialoglycoproteins released fragments of low molecular sizes, none of which reacted with the anti-midcycle glycoprotein antiserum. Cervical mucus collected from the estrogenic phase displayed a morphology supporting sperm migration, and this mucus retains the same morphology and reacts with the anti-midcycle glycoprotein antiserum following mild treatment with sialidase and subsequently with Pronase. These results imply that charged carbohydrate groups help maintain the structural and functional integrity of the mucus glycoprotein in its biological environment.
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PMID:Role of sialic acid and sulfate groups in cervical mucus physiological functions: study of Macaca radiata glycoproteins. 1457 2

Enzyme or chemical modification of intact red cells results in the destruction of some blood group antigens. The pattern of reactions of an antibody with red cells treated with various proteinases, with sialidase, and with the disulfide bond-reducing agent 2-aminoethylisothiouronium bromide (AET) can aid in antibody identification. This information can prove particularly beneficial with antibodies to antigens of very high frequency, where antigen- negative cells may be difficult to obtain. Provided in this article is a table listing most of the authenticated high-frequency red cell antigens and the effect on those antigens of trypsin, chymotrypsin, a mixture of trypsin and chymotrypsin, papain, pronase, sialidase, and AET.
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PMID:Effect of enzymes on and chemical modifications of high-frequency red cell antigens. 1594 59

Many Clostridium perfringens strains produce NanI as their major sialidase. Previous studies showed that NanI could potentiate C. perfringens epsilon toxin cytotoxicity by enhancing the binding of this toxin to host cells. The present study first determined that NanI exerts similar cytotoxicity-enhancing effects on C. perfringens enterotoxin and beta toxin, which are also important toxins for C. perfringens diseases (enteritis and enterotoxemia) originating in the gastrointestinal (GI) tract. Building upon previous work demonstrating that purified trypsin can activate NanI activity, this study next determined that purified chymotrypsin or mouse intestinal fluids can also activate NanI activity. Amino acid sequencing then showed that this effect involves the N-terminal processing of the NanI protein. Recombinant NanI (rNanI) species corresponding to major chymotrypsin- or small intestinal fluid-generated NanI fragments possessed more sialidase activity than did full-length rNanI, further supporting the proteolytic activation of NanI activity. rNanI species corresponding to proteolysis products also promoted the cytotoxic activity and binding of enterotoxin and beta toxin more strongly than did full-length rNanI. Since enterotoxin and beta toxin are produced in the intestines during human and animal disease, these findings suggest that intestinal proteases may enhance NanI activity, which in turn could further potentiate the activity of intestinally active toxins during disease. Coupling these new results with previous findings demonstrating that NanI is important for the adherence of C. perfringens to enterocyte-like cells, NanI sialidase is now emerging as a potential auxiliary virulence factor for C. perfringens enteritis and enterotoxemia.
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PMID:Native or Proteolytically Activated NanI Sialidase Enhances the Binding and Cytotoxic Activity of Clostridium perfringens Enterotoxin and Beta Toxin. 2903 29


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