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 effects of a range of commercially available proteases and glycosidases on blastocyst development and hatching were examined on rabbit embryos cultured from the morula stage in a defined medium supplemented with charcoal-treated bovine serum albumin. The proteases tested were trypsin, alpha-chymotrypsin, thrombin, elastase, plasmin, papain, clostripain, collagenase, Streptomyces griseus protease and cathepsin C. The glycosidases tested were neuraminidase, alpha-mannosidase, beta-galactosidase and hyaluronidase. None of these enzymes appeared to stimulate blastocyst growth. The only enzymes which digested the embryonic investments, the zona and mucin coat, sufficiently to cause complete blastocyst hatching were trypsin and Streptomyces griseus protease at relatively low concentrations (250 ng/ml) and chymotrypsin and elastase at higher concentrations.
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PMID:A survey of the effects of proteases and glycosidases on culture of rabbit morulae to blastocysts. 353 6

Colony-stimulating factor 1 (CSF-1) was purified from the serum-free conditioned medium of a human pancreatic carcinoma cell line (MIA PaCa-2) by a combination of conventional chromatography and high-performance liquid chromatography. The purity of human CSF-1 was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with a diffuse single band of Mr 42,000-50,000 and by N-terminal amino acid analysis of glutamate residue. The CSF-1 was stable at 50 degrees C for 30 min. It is sensitive to treatment with trypsin, chymotrypsin, and subtilisin but less sensitive to papain digestion. Treatment of CSF-1 with different glycosidases did not affect the biological activity. Sulfhydryl reagents such as dithiothreitol (DTT), iodoacetic acid, and N-ethylmaleimide did not affect the biological activity at the concentration of 1 mM. However, CSF-1 activity was inhibited totally by the combination of 10 mM DTT and 1 mM SDS. Under denaturing and reducing conditions, CSF-1 appeared on SDS-PAGE as a single protein band of Mr 21,000-25,000 and concurrently lost its activity, indicating that human CSF-1 possibly consists of two similar subunits and that the intact quaternary structure is essential for the biological activity. When treated with neuraminidase and endo-beta-D-N-acetylglucosaminidase D, the molecular weight of CSF-1 was reduced to 36,000-40,000, and to 18,000-20,000 in the presence of mercaptoethanol. Because of the specificity of endo-beta-D-N-acetylglucosaminidase D, it is suggested that the carbohydrate moieties are Asn-linked "complex-type" units.
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PMID:Purification and characterization of human colony-stimulating factor 1 from human pancreatic carcinoma (MIA PaCa-2) cells. 354 83

A monoclonal antibody, SZ-2, reacts specifically on human platelets and megakaryocytes. The platelets from 10 normal donors are bound to 15,200 +/- 4,100 SZ-2 molecules/platelet. The antigen recognized by SZ-2 is chymotrypsin-sensitive but neuraminidase-insensitive, and has been identified as glycoprotein Ib (GPIb) by an affinity chromatography technique. SZ-2 is different from other monoclonal antibodies to GPIb. It inhibits not only platelet aggregation induced by ristocetin, but also platelet aggregation induced by collagen (type I) and by PAF. SZ-2 also inhibits platelet serotonin and beta-thromboglobulin release in response to these stimuli.
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PMID:Studies on monoclonal antibodies against human platelets--a monoclonal antibody to human platelet glycoprotein I--SZ-2. 365 97

The addition of the tumor promoting phorbol ester 12-O-tetradecanoyl phorbol 13-acetate to intact human red blood cells activates protein kinase C and stimulates the phosphorylation of the membrane skeletal proteins band 4.1 and band 4.9 as well as two proteins of molecular mass 115 and 110 kDa. We show that 12-O-tetradecanoyl phorbol 13-acetate promotes the association of cytosolic protein kinase C with the red cell membrane and that the enzyme is present on ghost membranes but is largely absent from inside-out vesicles. We show that micromolar Ca2+ added to ghosts also promotes the phosphorylation of band 4.1 and the approximately 100-kDa proteins, a reaction which has not been described previously. Digestion and extraction studies show that the 100-kDa proteins are unrelated to band 3 since they are absent from NaOH stripped membranes, but are found in Triton-prepared cytoskeletons. Digestion of intact red cells with chymotrypsin or neuraminidase, which attack principally band 3 and glycophorin, respectively, markedly inhibits protein kinase C phosphorylation of band 4.1 in red cells and ghosts and of the 100-kDa proteins in ghosts. These enzymes have no effect upon the activity of the Ca2+-activated phosphorylation reaction, suggesting that it does not involve protein kinase C. These results shed light on two phosphorylation reactions which act exclusively on red cell membrane skeletal proteins. Our findings suggest that digestion of the integral membrane proteins band 3 and glycophorin, the principal targets of external protease digestion, affects the activity or specificity of protein kinase C. Finally we have described two apparently novel approximately 100-kDa phosphorylated proteins which are components of Triton-prepared red cell membrane skeletons.
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PMID:Phorbol ester- and Ca2+-dependent phosphorylation of human red cell membrane skeletal proteins. 371 Nov 3

Monoclonal antibodies elicited by immunization with mumps virus glycoproteins were selected with either native or chymotrypsin-treated mumps virus in an enzyme-linked immunosorbent assay. Group I antibodies which preferentially recognized chymotrypsin-treated virus failed to recognize native mumps virus hemagglutinin-neuraminidase (HN). They did react with sodium dodecyl sulfate-denatured HN and the HN chymotryptic fragments HNc2' (molecular weight, 41,000) and HNc1 (molecular weight, 32,000) after transfer to nitrocellulose paper. In contrast, group II antibodies, which preferentially recognized native virus in the enzyme-linked immunosorbent assay, reacted with native HN but failed to bind HN after sodium dodecyl sulfate denaturation. These two groups of monoclonal antibodies were used to define the maturation pathway of the mumps virus HN in infected cells. The HN initially appeared as a 76,000-molecular-weight polypeptide and was recognized only by group I antibodies. A truncated form of HN, HNT (molecular weight, 63,000), was synthesized in the presence of tunicamycin and was also recognized only by group I antibodies. The 76,000-molecular-weight HN was rapidly converted to a 74,000-molecular-weight polypeptide; this form of HN was recognized only by group II antibodies. The oligosaccharide side chains were modified, and intermolecular disulfide bonds were formed as HN was transported to the cell surface. The disulfide-linked oligomers of HN were direct precursors of the HN found in mature virus.
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PMID:Intracellular maturation of mumps virus hemagglutinin-neuraminidase glycoprotein: conformational changes detected with monoclonal antibodies. 373 88

Human polymorphonuclear leukocytes can be activated by various inflammatory stimuli to display increased cell aggregation which is potentially an important pathogenetic mechanism. This study describes a soluble factor produced by concanavalian A-stimulated lymphocytes that causes human leukocytes to aggregate. This factor could be assayed quantitatively by measuring the light absorbance of polynuclear leukocyte suspension using a spectrophotometer. The lymphokine involved, namely the leukocyte aggregating factor (LAgF) was released by non pulse exposure to the mitogen for up to 72 hr with a maximum at 48 hr. LAgF was characterized by Sephadex gel filtration, chromatofocusing, enzymatic and chemical treatment. Sephadex G 100 gel filtration showed LAgF activity in a molecular range of 40,000-65,000. Chromatofocusing of culture supernatant showed LAgF in a single broad peak (4.8-5.4) with a maximum activity at pI 5.2. Human LAgF was heat sensitive, inactivated by treatment with chymotrypsin, and not affected by neuraminidase. Activity was partially recovered from the supernatant after protein precipitation with 1 M perchloric acid and not destroyed by 0.02 M sodium periodate. These findings characterize LAgF as a protein. These data suggest that LAgF is not different from leukocyte inhibiting factor by virtue of its size and physiological properties.
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PMID:Activated human lymphocytes secrete a soluble factor that aggregates leukocytes. 375 54

We recently reported a new lymphokine activity that affects fibroblasts by inhibiting their spontaneous migration. Human fibroblast migration inhibitory factor (FIF) obtained from concanavalin A (Con A)-stimulated human lymphocytes was characterized by Sephadex gel filtration and by enzyme treatment. FIF was found to be stable at 56 degrees C for 15 min but destroyed at 80 degrees C or at pH lower than 5. Gel filtration revealed two peaks of FIF activity 15,000 and at 34,000 Da. FIF activity was lost following treatment with trypsin, chymotrypsin, and neuraminidase and FIF could not be generated in the presence of inhibitors of glycosylation, suggesting that the molecule was a glycoprotein. FIF could be removed by adsorption to human fibroblasts but not to PMN, monocytes, or red blood cells. Further studies were carried out to investigate the role of sugars in the interaction of FIF with the target cells. Human FIF activity was significantly reduced in the presence of several sugars including alpha-methyl-D-mannoside, L-xylose, N-acetyl-D-glucosamine, D-mannose, L-rhamnose but not L-fucose. Preincubation of human fibroblasts with alpha-methyl-D-mannoside prevented their response to FIF. In contrast, pretreatment of fibroblasts with mannosidase had no effect, suggesting that alpha-methyl-D-mannoside was an essential component of the FIF molecule recognized by the FIF receptor on fibroblasts.
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PMID:Physicochemical characterization of human fibroblast migration inhibitory factor. 383 94

A 92,000 D protein was identified associated with the membrane of host erythrocytes infected with the FCB1 Plasmodium falciparum strain from Colombia. The same protein was identified in the knob-forming Gambian (and the Malayan Camp) strain, but was not present in all the corresponding knobless strains. In the FCB1 strain as well as in the FCR3 strain the protein is synthesized during the ring-stage period. The cleavage products of the 92,000 D protein were investigated by peptide mapping following limited proteolytic digestion with Staphylococcus aureus V8 protease. The 92,000 D protein cleavage products from both the Colombian and the Gambian strains were identical. Moreover, both the proteins were sensitive to trypsin and chymotrypsin and also to treatment with neuraminidase. Enzymatic removal of the protein from the erythrocyte membrane by trypsin or chymotrypsin did not affect parasite maturation. The merozoites thus produced were fully invasive and the morphology of the knobs was unaltered. When the erythrocyte membrane was treated with trypsin before the time of synthesis of the 92,000 D protein, it was not possible to identify the protein in membranes of later stages of infected erythrocytes, indicating that the protein cannot be inserted into the membrane cytoskeleton compartment. Knobs, however, were formed more or less normally, suggesting that it is not the accumulation of this protein which products the knobs.
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PMID:The relationship to knobs of the 92,000 D protein specific for knobby strains of Plasmodium falciparum. 388 5

Monoclonal IgG1 antibodies 2C8 and 2F7, derived by immunization of mice with a glycoprotein-enriched fraction of human ovarian adenocarcinoma, recognized a 60 kD glycoprotein in the ovarian tumor but not in normal ovary. Survey of other normal adult tissues by an indirect solid-phase radioimmunoassay (RIA) revealed the presence of the antigen in trace amounts in various normal organs such as small intestine, liver colon and urinary bladder, except in lung where its concentration was as high as in tumors. Among fetal tissues tested, intestine and placenta had the highest activities. By RIA, about 50% of ovarian and colonic tumors had elevated levels of the antigen. All ovarian cyst fluids, both benign as well as malignant, also contained a high level of the antigen. Immunodepletion studies indicated that the antigen was distinct from carcinoembryonic antigen and the ovarian cancer antigens described in our laboratory with other monoclonal antibodies. The antigen bound to Con A-Sepharose and was eluted with 2% alpha-D-mannoside, was soluble in 0.6 M perchloric acid and stable at 100 degrees C for 30 min. The antigenic activity in isolated plasma membrane enriched fractions of ovarian adenocarcinomas was sensitive to trypsin, chymotrypsin or protease treatment but unaffected by neuraminidase, beta-galactosidase, periodate or methanol treatment. By immunoperoxidase staining, the antigen was localized in a variety of human tumors showing widespread distribution.
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PMID:Production and characterization of monoclonal antibody to a 60-kD glycoprotein in ovarian carcinoma. 389 88

Sera from 28 of the 113 normal children and adults (25%) studied were found to contain an immunoglobulin capable of causing complement-dependent lysis of normal platelets treated with small quantities of papain. This factor reacts equally well at 4 degrees C and at 37 degrees C with a determinant induced on platelets from normal subjects by treatment with papain or bromelain, but not by trypsin, chymotrypsin, or neuraminidase. It does not bind to red cells treated with any of these enzymes. The site(s) for which the factor was specific could not be induced on platelets from six patients with type I Glanzmann's thrombasthenia (lacking glycoproteins IIb and IIIa), in contrast to platelets from each of 20 normal donors. Isolation and characterization of the factor has been difficult because of its intolerance to chemical and physical manipulation. In 11 of the 20 individuals studied, however, it was found to have the properties of an IgM immunoglobulin. The factor appears to be different from any previously described, naturally occurring human immunoglobulin. It has not yet been shown to be associated with any disease state, but in the presence of complement, it is capable of causing profound damage to platelets previously subjected to minimal proteolysis, and the possibility that it can provoke platelet destruction in some conditions deserves further study.
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PMID:A naturally occurring, warm-reactive macroglobulin specific for papain-treated human platelets: preliminary characterization. 394 32


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