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)

A peak of immunoreactive pancreatic elastase 2 with a molecular weight consistent with that of a complex of elastase 2 and alpha 1-protease inhibitor (also referred to as alpha 1-antitrypsin) can be detected by radioimmunoassay in normal human serum or plasma (Geokas et al., J. Biol. Chem. 252:61-67, 1977). This material has been purified by gel filtration on Sephadex G-200 and by ion-exchange chromatography on DEAE-cellulose. The alpha 1-protease inhibitor-bound immunoreactive elastase 2 has been dissociated by incubation with hydroxylamine, and the resulting immunoreactive product isolated by gel filtration on Sephadex G-100. The dissociated immunoreactive elastase 2 was shown by affinity chromatography on turkey egg white inhibitor-bound agarose, before and after activation by bovine trypsin, to consist only of proelastase 2. A second peak of immunoreactive material associated with the high molecular weight fraction of plasma has been shown to result from a specific interaction of the 125I-labeled phenylmethanesulfonyl-elastase 2 employed as tracer in the radioimmunoassay with alpha 2-macroglobulin, resulting in apparent immunoreactivity. These results demonstrate that all of the detectable immunoreactive pancreatic elastase 2 in normal human plasma is proelastase 2 bound to alpha 1-protease inhibitor.
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PMID:Demonstration of a pancreatic proelastase 2-alpha 1-protease inhibitor complex in normal human plasma. 696 39

The mechanisms by which alpha 1-antitrypsin and antithrombin III inhibit trypsin were investigated by chemical stability studies and amino acid sequence analyses of the enzyme-inhibitor complexes. One-to-one covalently linked complexes were formed between each of the inhibitors and trypsin. The complexes were stable over the course of the experiments at pH 8 or lower, and benzamidine, hydroxylamine, thiols, guanidine, or dodecyl sulfate had no apparent effect on the stability of the complexes. The complexes dissociated slowly at pH 9 or greater. Neither of the inhibitors was active after dissociation from its complex with trypsin. Sequence analysis indicated that no new amino terminus was generated when alpha 1-antitrypsin formed its complex with trypsin, but that two new amino termini were formed in approximately one-to-one ratio when the complex dissociated. This may indicate that alpha 1-antitrypsin contains two inhibitory sites for trypsin in close spatial proximity on the molecule.
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PMID:Formation and dissociation of the covalent complexes between trypsin and two homologous inhibitors, alpha 1-antitrypsin and antithrombin III. 696 18

The amino acid sequence of the sulfate-binding protein from Salmonella typhimurium LT2 was determined by automated sequenator analysis of whole protein and fragments derived by chemical and enzymatic cleavage of whole protein. The fragments were products of limited trypsin digestion at arginine, cleavage at tryptophan by BrNps-skatole and o-iodosobenzoic acid, digestion with the protease from Staphylococcus aureus V8 at Glu-X bonds, cleavage by hydroxylamine at Asn-Gly bonds, and subdigestion with trypsin, chymotrypsin, and the Staphylococcus protease. The COOH-terminal sequence was confirmed using carboxypeptidase B and amino acid analysis. The sulfate-binding protein was determined to contain a single polypeptide of 310 residues with a molecular weight of 34,667 calculated from the sequence.
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PMID:Amino acid sequence of the sulfate-binding protein from Salmonella typhimurium LT2. 698 15

The peptide alpha 1(III)-CB9 was prepared and purified from human liver, and its amino acid sequence was determined. Automated Edman degradation of the intact peptide and peptides derived from selective cleavage with hydroxylamine and digestions with trypsin, thermolysin, and Staph V8 protease enabled determination of the complete amino acid sequence. The peptide alpha 1(III)-CB9 represents the COOH terminus of the helical (pepsin-resistant) portion of type III collagen and terminates in a Cys-Cys sequence responsible for the intramolecular disulfide cross-linkages with other chains. The present work completes the entire amino acid sequence of the helical (pepsin-resistant) portion of human cirrhotic liver type III collagen consisting of peptides alpha 1-(III)-CB3-7-6-1-8-10-2-4-5-9. The COOH terminus of human liver alpha 1(III) contained two additional triplets which, together with the extra triplet at the NH2 terminus in alpha 1(III)-CB3, make the helical portion of type III collagen longer than alpha 1(I) by nine residues (three Gly-X-Y triplets). The helical region of human liver type III collagen, therefore, consists of 1023 amino acids or 341 triplets.
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PMID:Covalent structure of collagen: amino acid sequence of alpha 1(III)-CB9 from type III collagen of human liver. 701 80

This review deals with some structural features of the collagen molecules involved in the adhesion of platelets representing the initial step of hemostasis, thrombosis, and (partly) atherosclerosis. The adhesion occurs at the level of a vascular lesion or deendothelialized area, whatever the genetic type of collagen. In vitro experiments with purified collagens have shown that vascular interstitial collagens (types I and III, the latter present in subendothelium) as well as basement membrane-derived collagens (types IV and V) induce an adhesion of platelets, provided that an ordered arrangement linked to the quaternary and tertiary structures of their molecule is preserved. Whatever the quaternary structure, the important point seems to be the size of the fibers and more precisely the availability of an optimal number of adhesion sites on multimerized fibers. Various direct or indirect proofs (for example, the occurrence of the impairment of collagen multimerization on platelet adhesion/aggregation) are reviewed. Our recent studies on interstitial collagens have shown the involvement of certain specific amino-acid sequences obtained after cyanogen bromide cleavage of collagen. These are the C-terminal alpha1 (I) CB6 peptide of the alpha 1 chains of type I collagen (216 amino acids) and the central alpha1 (III) CB4 peptide from type III collagen (149 amino acids) Cleavage of this last peptide by chymotrypsin, hydroxylamine, and trypsin has suggested the possibility that a nonapeptide (sequence gly-lys-hyp-gly-glu-hyp-gly-pro-lys) is a minimum site of adhesion for platelets. This assumption has been reinforced by the fact that a synthetic nonapeptide with this sequence specifically inhibits the aggregation of platelets to collagen in vitro. The adhesion of platelets may consequently be due to the repetitive staggering of short amino acid sequences (such as this nonapeptide from type III collagen) along the rigid structure formed by a multimerized collagen fiber.
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PMID:[The adhesion of blood platelets to collagen: molecular features of collagen (author's transl)]. 702 81

The proteinaceous coat associated with the cytoplasmic side of milk lipid globule membranes (MLGM) was prepared from bovine and caprine milk by removal of membrane material with non-ionic detergent. These coat preparations, which were enriched in two major proteins, a glycoprotein of polypeptide M, 67 000 (butyrophilin) and a non-glycosylated protein of polypeptide Mr 155 000 (xanthine oxidase), contained small amounts of fatty acids which could not be removed by exhaustive extractions with organic solvents. Both butyrophilin and xanthine oxidase of bovine MLGM were excised and eluted from SDS-polyacrylamide gels and were shown to contain 1 to 2 moles of bound fatty acids per mole of protein. Palmitic, stearic and oleic acids were the predominant protein-bound fatty acids, but no specificity for binding of individual fatty acids was observed. The fatty acids were not rendered soluble in organic solvents when the protein preparations were incubated with phospholipases A or C or with trypsin. Treatment with 0.25 M NaOH at 100 degrees C for 1 h or with 1 M hydroxylamine at 4 degrees C for 16 h, however, released virtually all of the fatty acids associated with these proteins. Similar results were obtained with two major proteins, bands 3 and 4.1, or rat erythrocyte plasma membrane. By contrast, skeletal muscle actin and serum albumin had no bound fatty acids that could be released by alkali treatment. These results show that fatty acids are bound to a number of membrane-associated proteins, both glycosylated and unglycosylated, via linkages that resist purification of the proteins on SDS-polyacrylamide gel electrophoresis and are suggestive of covalent attachment of fatty acids to these proteins. The possible involvement of this acylation in processes characterized by local changes of membrane shape and plasticity is discussed.
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PMID:Tight attachment of fatty acids to proteins associated with milk lipid globule membrane. 706 4

The detailed proof of the 437-residue amino acid sequence (Mr 48,969) of porcine heart citrate synthase (EC 4.13.7) is described. The S-carboxymethylated protein has been cleaved at methionine (cyanogen bromide) and arginine (trypsin digest of citraconylated enzyme) residues to yield 14 and 17 major peptides, respectively. Peptides were initially fractionated by gel filtration, and those useful for sequence analysis were purified by high-performance liquid chromatography. Sequence analyses were performed on these primary peptides and on subpeptides generated by cleavage with the bromine adduct of 2-[(2-nitrophenyl)sulfenyl]-3-methylindole, Staphylococcus aureus V8 protease, trypsin, chymotrypsin, or acid. The overall sequence was confirmed by analyzing products of cleavage by hydroxylamine, acid, and subtilisin. A novel feature of the sequence is the identification of trimethyllysine at residue 368.
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PMID:Complete amino acid sequence of porcine heart citrate synthase. 709 27

The rigor complex of actin and trypsin-treated myosin subfragment 1 (S1) whose heavy chain was cleaved into three fragments (20K, 25K, and 50K) was cross-linked with a zero-length cross-linker, 1-ethyl-3-[3-(dimethyl-amino) propyl]carbodiimide. The cross-linking reaction generated three types of cross-linked products with apparent molecular weights of 65K, 68K, and 95K. The 65K, 68K, and 95K products were covalently linked complexes of actin-20K fragment of the S1 heavy chain, actin-alkaline light chain 1, and actin-50K fragment of the S1 heavy chain, respectively. Cross-linking sites of S1 heavy and light chains on the actin sequence have been determined by digesting the cross-linked products with cyanogen bromide or with hydroxylamine and then mapping resulting peptides on sodium dodecyl sulfate gels. The result indicates that some of the N-terminal acidic residues of actin at positions 1, 2, 3, 4, and 11 are cross-linking sites of the 20K and 50K fragments of the S1 heavy chain while some of its C-terminal acidic residues at positions 360, 362, and 363 are cross-linking sites of the alkaline light chain 1.
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PMID:Identification of myosin-binding sites on the actin sequence. 711 91

Myosin subfragment 1 (S1) was covalently labeled with a fluorescent dye, N-[7-(dimethylamino)-4-methyl-3-coumarinyl]maleimide (DACM), and then digested by trypsin to cleave S1 heavy chain into fragments. The DACM-labeled and trypsin-treated S1 was complexed with F-actin and treated with a zero-length cross-linker, 1-ethyl-3[3-(dimethylamino)propyl] carbodiimide (EDC). The cross-linking reaction generated a covalently linked complex of actin and the 20K fragment of S1 heavy chain, which exclusively incorporated the fluorescent dye, to form a fluorescent 65K cross-linked product. The 20K and 65K fluorescent peptides were isolated and purified and then subjected to cyanogen bromide and/or hydroxylamine cleavages. Mapping of fluorescent cleavage products on acrylamide gels revealed that the N-terminal 20 residues of the 20K fragment of S1 heavy chain contained a cross-linking site of actin.
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PMID:An actin-binding site on the 20K fragment of myosin subfragment 1. 713 30

Pyridoxal 5-phosphate (PLP) treated rat liver triamcinolone acetonide complex was trypsin-digested followed by hydroxylamine treatment. This complex displayed a considerable fraction of DNA binding capacity of the intact complex, which was lost if trypsin digestion had not been preceded by PLP treatment. At the same time trypsin reduced the size of the complex regardless PLP pretreatment. These findings reveal that DNA binding does not require a large complex.
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PMID:Pyridoxal 5-phosphate protection of trypsin cleavage site on the glucocorticoid receptor protein. 717 55


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