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)

The Vicia angustifolia proteinase inhibitor was incubated with p-toluenesulfonyl-L-phenylalanine chloromethyl ketone-trypsin (EC 3.4.21.4) and a main product was isolated. The purified product was different to the first trypsin-modified V. angustifolia inhibitor. The C-terminal residues of the new derivative were arginine, which was also the C-terminal of the cleaved antitryptic site; lysine was a newly exposed C-terminal. These results suggest that the new derivative lacks the C-terminal portion of the native inhibitor, which has asparagine at its C-terminus. The liberated C-terminal peptide had the following amino acid sequence: H-Glu-Glu-Val-Ile-Lys-Asn-OH. The derivative lacking the C-terminal hexapeptide still possesses inhibitory activities against trypsin and alpha-chymotrypsin (EC 3.4.21.1), however, its antichymotryptic activity was inactivated by incubation with chymotrypsin at pH 8.0.
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PMID:Isolation and activities of the trypsin-modified Vicia angustifolia proteinase inhibitor lacking carboxyl-terminal hexapeptide. 3 67

Rosette formation with unsensitized sheep erythrocytes is a characteristic of human thymus dependent lymphocytes. Release of glycopeptides from the sheep erythrocyte by trypsin reduces rosette formation. These tryptic glycopeptides inhibit rosette formation by untrypsinized sheep erythrocytes; this suggests that rosetting is mediated by erythrocyte surface glycopeptides. To investigate the molecular nature of this interaction, we examined the abilities of various model compounds to act as haptenic inhibitors of rosette formation. Inhibition is given by glycopeptides bearing oligosaccharide units rich in sialic acid, galactose, N-acetylglucosamine, and mannose linked to asparagine residues through glycosylamine bonds. Among compounds tested, fetuin glycopeptide is most effective, but human transferrin glycopeptide and human erythrocyte glycopeptide I also inhibit rosette formation. Other compounds including human erythrocyte glycopeptide II, human IgG glycopeptide, lacto-N-neotetraose, 3'- and 6'-sialyllactose show no significant inhibition. Neither sialic acid, galactose, manose, nor N-acetyl-glucosamine alone inhibits rosette formation. Stepwise degradation of fetuin glycopeptide established the galactose residues as important determinants of inhibitory activity. Fetuin glycopeptide blocks rosette formation when added to a suspension of human lymphocytes and sheep erythrocytes or when preincubated with human lymphocytes, but not when preincubated with sheep erythrocytes. Studies of the binding of [3H] fetuin glycopeptide to normal lymphocytes demonstrate 7.5 x 10(6) saturable binding sites per cell. No saturable binding of this compound to sheep erythrocyte membranes is observed. Compared to normals, lymphocytes from patients with chronic lymphatic leukemia demonstrate decreased fetuin glycopeptide binding with a mean of 0.9 x 10(6) sites per cell. This decreased binding correlates with the impaired ability of these cells to form rosettes. The data suggest that fetuin glycopeptide inhibits rosette formation by binding to the thymus-dependent cell where competition occurs with sheep erythrocytes for specific lymphocyte surface receptors.
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PMID:Rosette formation between human lymphocytes and sheep erythrocytes. Inhibition of rosette formation by specific glycopeptides. 5 39

Cell surface protein is the major cell surface glycoprotein of chick embryo fibroblasts. We have isolated and purified this glycoprotein and find that it is an adhesive protein that increases cell-cell and cell-substratum adhesiveness in a variety cellular adhesion assays. Transformation of chick fibroblasts results in decreased quantities of CSP due primarily to a fivefold reduction in CSP biosynthesis, although increased proteolytic degradation and shedding from the cell surface also contribute. The decreased biosynthesis is apparently due to a fivefold reduction in translatable mRNA for CSP. Reconstitution of isolated purified CSP on 14 transformed cell lines from several species results in reversion to a more normal fibroblastic morphology, adhesiveness, cell surface architecture, microfilament bundle organization, motility, and alignment at confluence. Cell surface protein does not restore growth control. The effects of CSP appear to be due to at least two actions, increased cell-substratum adhesion plus altered cell-cell interactions. Untransformed chick cells treated with affinity-purified antibodies to CSP develop the rounded morphology characteristic of many transformed cells that are deficient in CSP (LETS protein). Cell surface protein is found primarily in fibrillar aggregates on the cell surface. These CSP fibrils are relatively immobile and do not affect the mobility of other cell surface components. However, CSP can be eventually redistributed to caplike structures with anti-CSP. Isolated CSP consists of highly asymmetric disulfide-linked dimers and multimers. The interchain disulfide bridges are confined to a short terminal fragment that is readily removed by trypsin. Cell surface protein and cold-insoluble globulin have similar compositions but differ in solubility and amino termini. Cell surface protein contains primarily asparagine-linked oligosaccharides that appear to be responsible for CSP's concanavalin A receptor activity. Inhibition of CSP's glycosylation by treatment with tunicamycin results in decreased CSP due to marked increases in its degradation rate, without inhibition of synthesis or secretion. Studies of this major cell surface glycoprotein have provided insight into the biochemical mechanisms of cellular adhesion, morphology, and social interaction and provide an approach to analyze the dynamics and regulation of protein synthesis, glycosylation, secretion, and turnover.
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PMID:Transformation-sensitive cell surface protein: isolation, characterization, and role in cellular morphology and adhesion. 29 64

The single polypeptide chain of about 460 amino acids of porcine pancreatic lipase (EC 3.1.1.3) has been fragmented into five peptides by cyanogen bromide cleavage [Rovery, M., Bianchetta, J. & Guidoni, A. (1973) Biochim. Biophys. Acta, 328, 391--395]. The sequence of the first three cyanogen bromide peptides (CNI, CNII, CNIII), including a total of 234 amino acids, was fully elucidated. Automatic or manual Edman degradation was performed on the different peptides. Fragmentations of the CN peptides were accomplished by digestions with trypsin (after citraconylation or 1,2-cyclohexanedione treatment), chymotrypsin and Staphylococcus aureus external protease. Hydrolysis of unreduced material by pepsin and thermolysin, performed in order to determine the S-S bridge positions, provided useful overlapping peptides. The glycan moiety of lipase is bound to Asn-166. The non-essential tyrosine specifically blocked by diisopropylphosphorofluoridate is Tyr-49 in a cluster of asparagine and glutamine residues. The existence of a highly hydrophobic sequence (206--217) at the C terminus of the CNII fragment is noteworthy.
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PMID:Porcine pancreatic lipase. Sequence of the first 234 amino acids of the peptide chain. 38 Sep 92

The primary structure of human erythrocyte carbonic anhydrase C has been determined. The single polypeptide chain contains 259 amino acid residues devoid of disulfide bridges. The experimental approach has involved restriction of the action of trypsin to arginyl bonds by amidination of the lysyl side chains. The six tryptic fragments obtained have been separated and sequenced by manual techniques. During the sequence work on human carbonic anhydrase C, 3 very easily deamidated asparagine residues were noted, all occurring in -Asn-Gly- sequences. The deamidation which takes place even under normal conditions of peptide preparation seems to be associated with a beta-aspartyl shift. A few minor differences existing between our structure and the results from another laboratory are discussed. A brief comparison is made with the primary structures of other carbonic anhydrases with regard to the function of some amino acid residues in the active site of the enzymes.
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PMID:Primary structure of human carbonic anhydrase C. 82 50

Two isoinhibitors (II and III-B) have been isolated from kidney bean (Phaseolus vulgaris L.) in a highly purified state. Both were active against trypsin and chymotrypsin to the same extent. Their amino acid composition is characterized by a high content of half-cystine, aspartic acid (or asparagine) and serine, by the absence of valine, methionine and tryptophan. Glycine and serine were N-terminal in II and III-B respectively. Both isoinhibitors have C-terminal leucine.
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PMID:[Isolation and properties of trypsin isoinhibitors from kidney beans]. 90 94

The membrane penicillinase of Bacillus licheniformis 749/C is a phospholipoprotein carrying extra residues of asparagine or aspartate, serine, glutamine or glutamate and glycine not present in the exoenzyme (Yamamoto, S., and Lampen, J.O. (1976) J. Biol. Chem. 251, 4095-4101). Cleavage of the membrane enzyme with trypsin yielded a phospholipipopeptide and a hydrophilic penicillinase differing from exopenicillinase only by the absence of the NH2-terminal lysine residue. Phosphatidylserine was isolated from a pronase digest of the phospholipopeptide. The partial sequence of the phospholipopeptide is: phosphatidylserine-(Ser3, Glx5, Asx7, Gly5)-Asp-Gin-Ser-Lys-COOH with the lysine being the NH2-terminal residue of the usual exoenzyme. The fatty acids present in the membrane enzyme and in the phospholipopeptide had essentially the same composition (predominantly n-16:0, ante iso-17:0, n-18:0, and n-18:1). These acids were also found in the total membrane lipids, although in very different proportions; thus, the phosphatidic acid residue of the phosphatidylserine is probably formed by the usual synthetic pathway for membrane phospholipids, but some special feature of the process affects the nature of the component fatty acids.
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PMID:The hydrophobic membrane penicillinase of Bacillus licheniformis 749/C. Characterization of the hydrophilic enzyme and phospholipopeptide produced by trypsin cleavage. 93 23

Commercially available Tos-PheCH2Cl-treated or untreated bovine trypsin (EC 3.4.21.4) is shown to catalyse minor tryptic hydrolysis at the carboxyl side of asparagine residues in globin chains. This activity is not removed by the purification of enzyme, using CM-cellulose chromatography and subsequent affinity chromatography on trypsin inhibitor columns, neither is it inhibited by Tos-PheCH2Cl treatment of the CM-cellulose purified enzyme. It is suggested that the ability to hydrolyse globin chains at asparagine residues may represent an inherent feature of the trypsin molecule.
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PMID:Tryptic hydrolysis at asparagine residues in globin chains. 94 49

The beta-chain of fibrin was cleaved with trypsin or cyanogen bromide. Carbohydrate containing fragments were isolated by affinity chromatography on concanavalin A-agarose. The fragments were analysed for amino acid sequence and for amino and carbohydrate composition. The sequence of 21 amino acid residues around the carbohydrate attachment point was determined. The carbohydrate carrying amino acid was identified as aspartic acid/asparagine.
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PMID:Carbohydrate linkage site in the beta-chain of human fibrin. 100 28

Four isoperoxidases of turnip root and isoperoxidase C of horseradish root were digested with trypsin, and their peptide maps, prepared by high-voltage paper electrophoresis, were compared. All five tryptic digests were completely soluble at pH 8. The maps were developed with a variety of general and specific reagents: ninhydrin, histidine, tyrosine, tryptophan and arginine reagents. Cystine peptides and cysteic acid derivatives have also been characterized. All detected half-cystine residues seemed engaged in disulfide bridges. For each individual peroxidase the number of specifically staining peptides agreed very well with the amino acid composition. The two most acidic peroxidases of turnip, P1 and P2, only differ significantly in one peptide. The P2 gene is tentatively proposed to have developed from the P1 gene by a single base mutation, changing an asparagine residue to alysine residue. A less acidic turnip peroxidase, P3, is distinct, although related to peroxidases P1 and P2. Horseradish isoperoxidase C also belongs to this group which appears to be closely related in the amino acid sequences around four disulfide bridges. Peroxidase P7 differs from this group, at least around two of its disulfide bridges, and therefore, may differ from the other four in parts of its three dimensional structure. Sequences of particular importance to peroxidase function must be present in all peroxidases. From the peptide mapping studies we only find two highly homologous sequences present in all five examined peroxidases. Both contain histidine. This finding corroborates previous suggestions of two histidine sequences near the peroxidase heme prosthetic group. The rules applied in relating peptides of different proteins are outlined, and the sources of errors in mapping of glycoproteins of high carbohydrate content (about 20%) are discussed in detail.
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PMID:Similarities and differences of five peroxidases from turnip and horseradish. Peptide mapping studies on glycoproteins. 117 50


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