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 orientation of human erythrocyte membrane protein was examined by enzymic iodination using lactoperoxidase with the glucose-oxidase system for generating peroxide, followed by proteolytic digestion. The outer surface of intact cells was labeled with 125I and the cytoplasmic surface of either resealed ghosts containing lactoperoxidase or of inside-out vesicles was labeled with 131I. Following iodination, the outer surface (resealed ghosts) or the cytoplasmic surface (outer surface of inside-out vesicles) was digested with trypsin, chymotrypsin, or pronase. Sodium dodecyl sulfate gel electrophoresis of the isolated membranes revealed three major and several minor peaks of radioactivity. Their surface orientation, defined within the limits of the specificity of the probes used, was as follows: the three major peaks consist of: (a) a 90,000 to 100,000 molecular weight component labeled on both surfaces; its proteolytic digestion profile indicated that it spans the membrane in an asymmetric manner and that it is composed of more than one peptide; (b) the major red cell membrane glycoprotein (apparent molecular weight 60,000) which is labeled and digested at only the outer surface; and (c) peptide(s) of high molecular weight (approximately 200,000), labeled and digested at only the cytoplasmic surface. The minor components include a glycoprotein of approximately 25,000 (apparent molecular weight) accessible to both surfaces and peptides of 60,000 to 70,000, 45,000, and 20,000 molecular weight labeled only on the inner surface.
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PMID:Arrangement of human erythrocyte membrane proteins. 80 40

Exposure of mycobacterial growth inhibitory factor (MycoIF) to trypsin, chymotrypsin, or neuraminidase decrease its ability to produce intracellular inhibition of mycobacterial growth within macrophages, suggesting that MycoIF was a glycoprotein. MycoIF was unaffected by deoxyribonuclease or ribonuclease. Supernatant fluids from antigenically stimulated H37Ra-immunized mouse spleen cells exposed to puromycin were unable to produce significant intracellular inhibition. This indicated that the presence of MycoIF activity in supernatant fluids required protein synthesis. The filtration of MycoIF-containing supernatant fluids on Sephadex G-150 demonstrated that significant MycoIF activity appeared only in those fractions which eluted on the downward side of the serum albumin peak. Based on protein standards filtered through the Sephadex gel, the molecular weight of MycoIF was calculated to be between 20,000 and 35,000. These calculations assumed that MycoIF is a globular protein. Attempts to purify MycoIF by anion exchange chromatography (diethylaminoethylcellulose) was not successful.
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PMID:Molecular weight and other characteristics of mycobacterial growth inhibitory factor produced by spleen cells obtained from mice immunized with viable attenuated mycobacterial cells. 81 60

The orientation of proteins and glycoproteins of the platelet surface has been studied using various surface probes and labeling reagents. A fourth major glycoprotein has now been detected in platelet plasma membranes by sodium dodecyl sulfate-gel electrophoresis in addition to the previously recognized glycoproteins I, II, and III. Glycoprotein IV Mr, = approximately 87,000) appears to be present on the inner aspect of the membrane or buried within it since it is not accessible to surface probes such as lactoperoxidase-catalyzed iodination, radiolabeling with transglutaminase and [14C]glycine ethyl ester, or proteolytic enzymes. The ratio of these four major membrane-bound glycoproteins is approximately 10:4:2:3. Contrary to previous reports, only one glycoprotein, glycoprotein III, is accessible to lactoperoxidase-catalyzed iodination in intact platelets. Differences in the rate of destruction of glycoprotein II in intact platelets by trypsin suggests that two components may be migrating in this region. Examination of the soluble fraction obtained following platelet homogenization showed the presence of a single soluble glycoprotein of molecular weight 148,000 comprising about 10% of total platelet sialic acid. Treatment of intact platelets with neuraminidase resulted in the quantitative loss of siliac acid from the soluble glycoprotein, and it was strongly labeled in the intact platelet by [14C]glycine ethyl ester in the presence of transglutaminase. Treatment of intact platelets with chymotrypsin which does not cause the platelet release reaction, caused the rapid conversion of the soluble glycoprotein to a macroglycopeptide. These results indicate a surface origin for the soluble glycoprotein rather than a cytoplasmic or granular origin. The term glycocalicin is suggested for this glycoprotein in view of its origin in the platelet glycocalyx.
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PMID:Platelet glycocalicin. I. Orientation of glycoproteins of the human platelet surface. 82 54

Pronase and alpha-chymotrypsin digested the major glycoprotein in the human and mouse red cell membranes and in SDS gel electrophoresis the glycoprotein disappeared accompanied by the appearance of a new band of lower mol. wt. However in the membranes of sheep, rat and rabbit, no digestion was demonstrated. The effects of pronase on anion permeability were almost identical for human and animal erythrocytes.
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PMID:Species difference in the effects of proteolytic enzymes on red cell membrane. 86 14

These studies describe the production of murine migration inhibitory factor (MIF)3 in sufficient quantities to allow its partial characterization by physiochemical and enzymatic methods. MIF was obtained from murine spleen cell cultures (C57BL/6 strain) stimulated with concanavalin A (Con A). Characterization of murine MIF was performed using Sephadex G-100 gel chromatography, isopycnic centrifugation in a CsCl density gradient, polyacrylamide disc electrophoresis, heat stability, and enzymatic treatment. MIF-containing and control fractions were assayed on normal C57BL/6 peritoneal exudate cells by using a microcapillary tube assay. Peak MIF activity was found in a Sephadex G-100 fraction containing molecules the size of albumin and slightly smaller, molecular weight 67,000 to 48,000. Murine MIF was stable to heating at 56 degrees C for 30 min but lost its activity at 80 degrees C for 30 min. Incubation of G-100 fractions containing MIF with water insoluble chymotrypsin destroyed the activity of MIF, indicating its protein nature. CsCl density gradient centrifugation revealed that murine MIF had a buoyand density greater than protein, consistent with its being a glycoprotein. Further, when subjected to disc electrophoresis on polyacylamide gels, murine MIF migrated in a region cathodal to albumin. Thus, mitogen stimulation of murine spleen cells produced MIF in quantities which allowed its partial characterization and purification, and its comparison with human and guinea pig MIF; this makes it feasible to analyze the role of murine MIF in cellular immunity and in its relationship to lymphocyte mediators which regulate humoral immune responses.
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PMID:Partial characterization of murine migration inhibitory factor (MIF). 110 23

Bovine and equine erythrocytes have been studied by three different surface modification techniques to investigate the accessibility of the surface components to the external medium. Lactoperoxidase labeling of equine erythrocytes results in a significant labeling of only one membrane component, a 100 000-mol.wt polypeptide corresponding to the membrane-spanning Component III of human erythrocytes. The major sialoglycoprotein of the equine erythrocyte is not labeled. This is in contradistinction to the situation for human and bovine cells, where both components are labeled. The equine membrane sialoglycoprotein is also not markedly affected by pronase, chymotrypsin or trypsin treatment of whole cells under the treatment conditions used, although it can be cleaved by pronase in isolated membranes. Experiments with the isolated glycoprotein show that its cleavage by trypsin is quite selective, whereas cleavage by pronase and chymotrypsin is much more extensive. Labelling of bovine red cells by galactose oxidase treatment followed by reduction with 3H-labeled borohydride yields radioactivity in only one major peak, that corresponding increase in labeling. Equine erythrocytes don not show significant labeling by this technique unless a neuraminidase pretreatment has been performed. Then only the major glycoprotein is labeled. Thus the equine glycoprotein is apparently inaccessible to the cell surface by standard surface modification methods, although it is clearly a surface component. These experiments point out some of the limitations of surface labeling and proteolysis methods in probing the accessibility of membrane components. The results suggest that apparent inaccessibility of the equine glycoprotein is due partially to its structure and partially to its localization in the membrane.
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PMID:Species variability in the modification of erythrocyte surface proteins by enzymatic probes. 112 Jan 55

Schistosomula of Schistosoma mansoni became resistant to antibody-dependent complement damage in vitro after pre-incubation with normal human erythrocytes (NHuE) whatever the ABO or Rh blood group. Resistant parasites were shown to acquire host decay accelerating factor (DAF), a 70 kDa glycoprotein attached to the membrane of NHuE by a GPI anchor. IgG2a mAb anti-human DAF (IA10) immunoprecipitated a 70 kDa molecule from 125I-labeled schistosomula pre-incubated with NHuE and inhibited their resistance to complement-dependent killing in vitro. Incubation of schistosomula with erythrocytes from patients with paroxysmal nocturnal hemoglobinuria (PNHE) or SRBC, which are DAF-deficient, did not protect the parasites from complement lesion. Supernatant of 100,000 x g collected from NHuE incubated for 24 h in defined medium was shown to contain a soluble form of DAF and to protect schistosomula from complement killing. Schistosomula treated with trypsin before incubation with NHuE ghosts did not become resistant to complement damage. On the other hand, pre-treatment with chymotrypsin did not interfere with the acquisition of resistance by the schistosomula. These results indicate that, in vitro, NHuE DAF can be transferred to schistosomula in a soluble form and that the binding of this molecule to the parasite surface is dependent upon trypsin-sensitive chymotrypsin-insensitive polypeptide(s) present on the surface of the worm.
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PMID:Mechanisms of evasion of Schistosoma mansoni schistosomula to the lethal activity of complement. 128 36

We investigated the effect of ulinastatin, a candidate anti-osteoarthritic drug, in comparison with indomethacin and triamcinolone, two well-known drugs for osteoarthritis, on IL-1 production by monocytes, proteoglycan synthesis by chondrocytes and superoxide generation by leukocytes. Ulinastatin, a glycoprotein purified from human urine, suppressed both the IL-1 production and the IL-1 induced reduction of proteoglycan synthesis. In addition, ulinastatin inhibited superoxide generation. These actions of ulinastatin seemed to be related to its inhibitory actions against serine proteases such as trypsin, alpha-chymotrypsin, plasmin, leukocyte elastase and leukocyte cathepsin G. Triamcinolone suppressed the IL-1 production more potently than ulinastatin and it also suppressed the IL-1 induced reduction of proteoglycan synthesis. Triamcinolone alone, however, reduced the proteoglycan synthesis, and it did not affect the superoxide generation. In contrast, indomethacin had no effect on proteoglycan synthesis and superoxide generation, although it accelerated the IL-1 production. These results indicate that these three drugs have different mechanisms of action on the factors involved in the pathogenesis of osteoarthritis. Since ulinastatin has broad actions, which are considered to be beneficial for preventing some process of osteoarthritic pathogenesis, ulinastatin is expected to be an useful drug for the treatment of osteoarthritis.
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PMID:[Mechanism of the anti-osteoarthritic action of ulinastatin in comparison with those of indomethacin and triamcinolone]. 131 79

The influence of diclofenac, given by continuous i.v. infusion starting preoperatively, on postoperative pain and inflammation was assessed in a double-blind, randomized, placebo-controlled study in 40 patients scheduled for major orthopedic surgery. Starting 30 min before induction the patients received either diclofenac (0.35 mg.kg-1 bolus followed by a constant-rate infusion of 90 micrograms.min-1) or placebo for 24 h. The pain intensity (VAS) and the amount of rescue narcotic (piritramide on demand) were significantly lower in the diclofenac group from 4 and 6 h postsurgery, respectively, till end of infusion. Acute phase proteins used as inflammation markers (C-reactive protein, alpha 1-chymotrypsin, alpha 1-acid glycoprotein, haptoglobin and coeruloplasmin) showed similar variations in both groups for 24 h. The diclofenac treatment had no influence on hematological and coagulation profiles, nor on muscle and liver enzymes in comparison with placebo. Both patients and observer rated the diclofenac treatment as significantly superior to the placebo treatment.
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PMID:Prophylactic diclofenac infusions in major orthopedic surgery: effects on analgesia and acute phase proteins. 137 1

The cell-free haemolymph of the mollusc Octopus vulgaris inhibited the proteolytic activity of the thermolysin against the high-molecular-mass substrate hide powder azure. The purified inhibitor was a glycoprotein composed of two identical 180 kDa disulphide-linked subunits. In addition to the inhibition of the metalloproteinase thermolysin, the protein inhibited the serine proteinases human neutrophil elastase, pig pancreatic elastase, bovine chymotrypsin, bovine trypsin and the cysteine proteinase papain. A fraction of the proteinase-inhibitor complex resisted dissociation after denaturation indicating that some of the proteinase molecules became covalently bound. The nucleophile beta-aminopropionitrile decreased the covalent binding of proteinases to the Octopus vulgaris protein, suggesting that this interaction is mediated by an internal thiol ester; the reactivity and the amino acid sequence flanking the reactive residues of the putative thiol ester were consistent with this hypothesis. Bound trypsin remained active against the low-molecular-mass chromatogenic substrate H-D-Pro-Phe-Arg p-nitroanilide and was protected from inhibition by active-site-directed protein inhibitors of trypsin; however, the bound trypsin was readily inhibited by small synthetic inhibitors. This indicates that the inhibition of proteinases is accomplished by steric hindrance. The proteinase-inhibitory activity of this protein is characteristic of inhibition by mammalian alpha-macroglobulins and the presence of a putative thiol ester suggests that the Octopus vulgaris proteinase inhibitor is a homologue of human alpha 2-macroglobulin.
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PMID:Purification and characterization of an alpha-macroglobulin proteinase inhibitor from the mollusc Octopus vulgaris. 137 44


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