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

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

EDCl is a novel glycoprotein, mol wt 27,000, isolated in 1976 from leukemic urine. It inhibits the serine proteases trypsin and chymotrypsin and is antigenically related to interalpha trypsin inhibitor (IATI), mol wt 170,000, a normal plasma antiprotease. Since psoriasis is a non neoplastic hyperproliferative state, we have now measured EDCl by a specific radioimmunoassay (RIA) in plasma and urine of 24 untreated psoriatic patients. EDCl was not detectable in normal urine (less than 1 mg/gm creatinine) or plasma (less than 1 mg/L). 55% of psoriatic urine specimens were positive by RIA, containing 8 to 110 mg/gm creatinine. 75% of plasmas were positive, containing 12 to 32 mg/L. Plasma and urine contents of EDCl were significantly (P less than .05) correlated with severity of clinical disease (% skin involved) but not with age, sex, distribution or type of lesion, family history or arthritis.
...
PMID:Accumulation of urinary cancer-related glycoprotein, EDCl, in psoriasis. 47 29

The possibility that the surface of the egg of the sea urchin Arbacia punctulata contains a species-specific receptor for sperm has been investigated. The extent of fertilization of eggs of A. punctulata, which is proportional to the number of sperm, is unaffected by the presence of either eggs or membranes prepared from eggs of Strongylocentrotus purpuratus. In marked contrast, membranes prepared from eggs of A. punctulata quantitatively inhibit fertilization of A. punctulata eggs by A. punctulata sperm. Several lines of evidence indicate that this inhibition is due to the presence of a membrane-associated glycoprotein that binds to the sperm, thus preventing them from interacting with receptor on the surface of the eggs. First, eggs treated with trypsin are incapable of being fertilized, although they can be activated with the Ca2+ ionophore A23187. Moreover, membranes prepared from eggs pretreated with trypsin do not inhibit fertilization of eggs. Second, receptor isolated in soluble form from surface membranes binds to sperm and thus prevents them from fertilizing eggs; the inhibition by soluble receptor is species-specific. Third, the soluble receptor binds to concanavalin A-Sepharose. Fourth, eggs are incapable of being fertilized if they are pretreated with concanavalin A. The specificity of inhibition, and the affect of trypsin and concanavalin A on intact eggs, suggest that the receptor is a species-specific macromolecule located on the surface of the eggs. The sensitivity of the receptor to trypsin, and its ability to bind to concanavalin A, indicate that it is a glycoprotein.
...
PMID:Identification of a sperm receptor on the surface of the eggs of the sea urchin Arbacia punctulata. 55 17

A quantitative assay was used to measure the rate of collection of a population of embryonic neural retina cells to the surface of cell aggregates. The rate of collection of freshly trysinized cells was limited in the initial stages by the rate of replacement of trypsin-sensitive cell- surface components. When cells were preincubated, or "recovered," and then added to cell aggregates, collection occurred at a linear rate and was independent of protein and glycoprotein synthesis. The adhesion of recovered cells was temperature and energy dependent, and was reversibly inhibited by cytochalasin B. Colchicine had little effect on collection of recovered cells. Antiserum directed against recovered cell membranes was shown to bind to recovered cells by indirect immunofluorescence. The antiserum also was shown to inhibit collection of recovered cells to aggregates, suggesting that at least some of the antigens identified might be involved in the adhesion process. The inhibitory effect of the antiserum was dose dependent . Freshly trypsinized cells absorbed neither the immunofluorescence activity nor the adhesion-inhibiting activity. Recovered cells absorbed away both activities. In specificity studies, dorsal neural retina cells adhered to aggregates of ventral optic tectum in preference to aggregates of dorsal optic tectum. The adhesive specificity of the dorsal retina cells was less sensitive to trypsin than the adhesive specificity of ventral retina cells which adhered preferentially to dorsal tectal aggregates only after a period of recovery.
...
PMID:A requirement for trypsin-sensitive cell-surface components for cell-cell interactions of embryonic neural retina cells. 56 49

Footpad adhesion sites pinch off from the rest of the cell surface during EGTA-mediated detachment of normal or virus-transformed murine cells from their tissue culture substrates. In these studies, highly purified trypsin and testicullar hyaluronidase were used to investigate the selective destruction or solubilization of proteins and polysaccharides in this substrate-attached material (SAM). Trypsin-mediated detachment of cells or trypsinization of SAM after EGTA-mediated detachment of cells resulted in the following changes in SAM composition: (a) solubilization of 50-70% of the glycosaminoglycan polysaccharide with loss of only a small fraction of the protein, (b) selective loss of one species of glycosaminoglycan-associated protein in longterm radiolabeled preparations, (c) no selective loss of the LETS glycoprotein or cytoskeletal proteins in longterm radiolabeled preparations, and (d) selective loss of one species of glycosaminoglycan-associated protein, a protion of the LETS glycoprotein, and proteins Cd (mol wt 47,000 and Ce' (mol wt 39,000) in short term radiolabeled preparations. Digestion of SAM with testicular hyaluronidase resulted in: (a) almost complete solubilization of the hyaluronate and chondroitin sulfate moieties from long term radiolabeled SAM with minimal loss of heparan sulfate, (b) solubilization of a small portion of the LETS glycoprotein and the cytoskeletal proteins from longterm radiolabeled SAM, (c) resistance to solubilization of protein and polysaccharide in reattaching cell SAM which contains principally heparan sulfate, and (d) complete solubilization of the LETS glycoprotein in short term radiolabeled preparations with no loss of cytoskeletal proteins. Thus, there appear to be two distinct pools of LETS in SAM, one associated in some unknown fashion with hyaluronate-chondroitin sulfate complexes, and a second associated with some other component in SAM, perhaps heparan sulfate. These data, together with other results, suggest that the cell-substrate adhesion process may be mediated principally by a heparan sulfate--LETS complex and that hyaluronate-chondroitin sulfate complexes may be important in the detachability of cells from the serum-coated substrate by destabilizing LETS matrices at posterior footpad adhesion sites.
...
PMID:Two functionally distinct pools of glycosaminoglycan in the substrate adhesion site of murine cells. 56 61

Egg lectin of Rana japonica, which specifically agglutinates transformed cells but does not agglutinate nontransformed cells and erythrocytes, has been isolated by gel filtration and successive ion-exchange chromatographies on diethylaminoethyl cellulose and carboxymethylcellulose columns and has been characterized as a homogeneous carbohydrate-free protein with a relative molecular weight of 13,500. The lectin, at a concentration of 1 microgram/0.1 ml, causes obvious cytoagglutination of various transformed and tumor cell. The receptor of the Erlich ascites tumor cells which inhibits the lectin-induced agglutination of the Ehrlich ascites tumor cells has been isolated and characterized. The receptor was solubilized from Ehrlich ascites carcinoma cells by treating a tumor cell suspension with insolubilized trypsin, and the solubilized receptor was isolated by gel filtration through Sephadex G-100, followed by ion-exchange chromatography on diethylaminoethyl cellulose. The receptor was identified as a homogeneous glycoprotein having about 25% carbohydrate. The receptor, at a concentration of 4 microgram/0.1 ml, completely inhibited the cytoagglutination of the Ehrlich carcinoma cells caused by three agglutination doses (about 3 microgram/0.1 ml) of the R. japonica lectin.
...
PMID:Egg lectin of Rana japonica and its receptor glycoprotein of Ehrlich tumor cells. 57 Apr 54

Myxoviruses (ortho- and paramyxoviruses) possess on their surface two virus-specific glycoproteins, the functions of which are largely understood; These glycoproteins are synthesized on the rought endoplasmic reticulum, and during their transport to the plasma membrane on smooth intracellular membranes, they undergo modification through proteolytic cleavage. In this way, the orthomyxovirus hemagllutinin is converted from a high-molecular weight form (HA) into two smaller cleavage products (HA1 and HA2). With the paramyxoviruses, the glycoprotein F, which is responsible for fusion and hemolysis, is derived from proteolytic cleavage of a precursor, F0. Furthermore, with a few strains of avirulent NDV, a precursor of the hemagglutinin-neuraminidase complex, (HN0), has been identified which again, as a result of proteolysis, undergoes cleavage to HN. Whether cleavage takes place is as much dependent on the structure of the glycoprotein as on the host cell type. Proteolytic cleavage is indeed not necessary for virus particle production but is required for infectivity. Virus particles which possess the uncleaved glycoproteins may be activated by in vitro treatment with trypsin. As evidenced by experiments with orthomyxovirus recombinants, the glycoproteins alone do not determine the pathogenicity of the viruses. With paramyxoviruses, the pathogenic and apathogenic strains show clear differences in their host range spectrum which is directly related to the sensitivity of their glycoproteins twoard proteases. These observations provide an initial sketch for the molecular basis of infectivity and pathogenicity with myxoviruses.
...
PMID:[Correlation between structure and pathogenicity of myxoviruses (author's transl)]. 57 26

The isolation and characterization of placemental protein PP5 is described. The purification was achieved by use of immunoadsorbents. From the tissue of one human term placenta an average amount of 15 mg PP5 can be extracted. PP5 apparently is specific for the placenta; it could not be detected in extracts from other human tissues. In sera from pregnant women PP5 is not present or only in trace amounts (less than 0.1 mg%). In the ultracentrifuge PP5 was found to have a sedimentation coefficient of 2.8 S and a molecular weight of 36,600 daltons. Electrophoretically the protein migrates as a fast beta1-globulin. The isoelectric point was determined to be 4.6. PP5 is a glycoprotein and contains 19.8% carbohydrates (hexoses 10.0%, hexosamine 4.4%, fucose 0.4%, sialic acid 5.0%). The amino acid composition of the protein is reported, too. PP5 was found to inhibit the activity of trypsin and plasmin; the biological role of this protein therefore may be the inhibition of proteases.
...
PMID:[Isolation and characterization of the placental protein pp5 (author's transl)]. 57 96

Ten-day-old embryonic chick neural retina release into the environment glycoprotein ligands which bind to homologous cells, inhibiting the lectin-induced redistribution of cell surface receptors. Material with identical activity is released from trypsin-dissociated neural retina cells that are allowed to repair in culture for 2 h and are then transferred to fresh medium. Release of ligand is inhibited by cytosine arabinoside, hydroxyurea, UDP, and EDTA, and is potentiated by MnCl2. These data suggest that a glycosyltransferase reaction plays a critical role in the turnover of the cell surface ligand. Reactivation of enzymatically deglycosylated ligand solutions by intact cells provides further support for this hypothesis. Release of ligand is also accompanied by a loss of the agglutinability of the cells by a tissue-specific component which accumulates in monolayer conditioned medium. Conditions which inhibit release maintain maximal agglutinability suggesting similar mechanisms mediate both processes.
...
PMID:The turnover of a tissue specific cell surface ligand which inhibits lectin induced capping. 61 88

The structural polypeptides of two strains of measles virus grown in Vero cells were analysed in SDS-PAGE slab gels. Six major polypeptides were identified with mol. wt. of 79000, 72000, 60000, 43000, 40000 and 36000. The largest polypeptide was sensitive to trypsin digestion and was the dominant glycosylated polypeptide identified when the virus was grown in medium containing 3H-fucose or 3H-glucosamine or when the virus was treated with galactose oxidase and labelled with 3H-sodium borohydride. It is concluded that the 79000 mol. wt. polypeptide represents the haemagglutinin. Treatment with non-ionic detergent removed this polypeptide and also the 40000 mol. wt. polypeptide from the virus envelope. The 40000 mol. wt. polypeptide is probably associated with haemolysin and cell fusion activities and is analogous to the F1 of paramyxoviruses. A polypeptide of mol. wt. approx. 20000 detected after glycoprotein labelling may represent the F2 of measles virus. The 43000 mol. wt. polypeptide co-migrates with cellular actin and is the only major measles polypeptide that is heavily labelled when the virus is grown on Vero cells prelabelled with 35S-methionine. Thus it may represent cellular actin incorporated into the virus during maturation. The quantity of the 72000 mol. wt. polypeptide relative to the other major polypeptides varied considerably in different virus preparations. The role of the polypeptide could not be defined. By analogy with previously published data the 60000 and 36000 mol. wt. polypeptides are inferred to represent nucleocapsid and membrane proteins, respectively.
...
PMID:Structural polypeptides of measles virus. 65 Jan 74

Radioiodinated normal rabbit IgG was used to detect Fc receptors on the surface of HeLa S3-2 cells infected with herpes simplex virus (HSV). Unlike the Fc receptors present on most leukocytes, these virus-induced Fc receptors were found to be sensitivite to trypsin at concentrations of enzyme as low as 0.1 mg/ml. Treatment of infected cells with neuraminidase enhanced the binding of IgG. Yet the HSV-induced Fc receptor(s) is probably a glycoprotein because its synthesis was inhibited by 2-deoxy-D-glucose at concentrations inhibiting glycoproteins but not total proteins. Binding of radioiodinated IgG to Fc receptors on infected HeLa S3-2 cells was unaffected by F(ab')2 fragments prepared from antisera against uninfected HeLa S3-2 cells or against human beta2-microglobulin. By contrast, anti-HSV F(ab')2 or Fab' fragments decreased binding of radioiodinated IgG to HSV-infected cells by 85%, and binding of radioiodinated Fc was also inhibited by anti-HSV Fab'.
...
PMID:Fc receptors induced by herpes simplex virus. I. Biologic and biochemical properties. 68 55


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---