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)

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 complete amino acid sequence of the major component myoglobin from Pacific common dolphin, Delphinus delphis, was determined by the automatic Edman degradation of several large peptides obtained by specific cleavages of the protein. More than 80% of the covalent structure was established by the degradation of the apomyoglobin and five peptides from: (1) cyanogen bromide cleavage at the two methionine residues, (2) trypsin cleavage of the acetimidated apomyoglobin at the three arginine residues, and (3) 2-p-nitrophenylsulfenyl-3-methyl-3'-bromoindolenine cleavage at the two tryptophan residues. The rest of the sequence was determined by use of the peptides prepared from further digestion of the central cyanogen bromide peptide with staphylococcal protease and trypsin. The primary structure of this myoglobin proved identical with that from the Atlantic bottlenosed dolphin, Tursiops truncatus, but showed four substitutions with respect to the sequence reported for the Black Sea dolphin which has also been given the designation Delphinus delphis.
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PMID:Complete primary structure of the major component myoglobin of Pacific common dolphin (Delphinus delphis). 91 8

The statistical availability of tryptophan and tyrosine residues with one ring face fully exposed to solvent was examined for two serine proteases and their derivatives by investigating the formation of charge transfer (CT) complexes between the aromatic donor residues of the protein and the acceptor 1-methylnicotinamide chloride. The availability of the ring face of one of the two exposed tryptophan residues in trypsin has been previously shown to be pH dependent and to parallel the acid side of the pH-activity profile of the enzyme. The present results indicate that, in diisopropylphosphoryl-trypsin (DIP-trypsin), this residue [which was identified as Trp-215 in native trypsin (chymotrypsin numbering)] is locked in a relatively rigid, pH-independent conformation with one ring face rotated out toward the solvent. In the zymogen and DIP-zymogen, the ring face is essentially unavailable. Chymotrypsin, like trypsin, has a pH-depent tryptophan residue available for complexation with the CT acceptor, but unlike trypsin, the pH dependence is apparently associated with dimerization of the enzyme. These and other data suggest this residue is the same as in the homologous trypsin structure, i.e., Trp 215, and that the ring face is mostly buried in the zymogen. Comparison of the crystal structure models of chymotrypsin and chymotrypsinogen shows that, as the specificity pocket opens up from its collapsed structure upon zymogen activation, the ring face of Trp-215 moves out and rotates relative to the surface of the enzyme in such a fashion as to become more accessible to solvent. These observations are in accord with the present CT results and provide additional support for the assignment of changes in Trp-215 availability to parallel changes in the conformation of the specificity pocket of these serine proteases. The present investigation also shows that, although a tryptophan ring face is partly exposed in DIP-chymotrypsin, its statistical availability more closely resembles that of the zymogen than the native enzyme. The reverse appears to be true for DIP-trypsin, which suggests the possibility that the specificity pocket in DIP-chymotrypsin may be partially collapsed while the catalytic residues are frozen in the conformation of the acyl-enzyme.
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PMID:Flexibility in the specificity site of serine proteases. 94 68

Five proteinase inhibitors which all inhibit the activity of bovine trypsin [EC 3.4.21.4] were isolated from African Elapid venoms of Hemachatus haemachatus (HHV, Ringhal's cobra) and Naja nivea (NNV, Cape cobra). All the inhibitors were essentially homogeneous by polyacrylamide gel electrophoresis in the presence or absence of sodium dodecylsulfate. Amino acid analysis and terminal analysis also supported their chemical homogeneities, except for one of the two inhibitors from Hemachatus haemachatus venom. The isolated inhibitors had a molecular weight of about 6,500, consisting of 52 to 57 amino acid residues, and they were all devoid of tryptophan. However, their amino acid compositions differed from each other. One of the three inhibitors isolated from Naja nivea venom, designated NNV inhibitor Ia, was unique, in that 4 half-cystinyl residues per mole fof the polypeptide were present, whereas all the others contained six residues. Of the isolated proteinase inhibitors, the complete amino acid sequences of two major inhibitors were established by manual and automatic Edman degradations and standard enzymatic techniques. Each of the inhibitors, designated HHV inhibitor II and NNV inhibitor II, consisted of 57 amino acid with arginine and glycine at the NH2- and COOH-termini, respectively. Both contained six half-cystines in disulfide linkages, and their overall amino acid sequences were similar, showing 91% homology. The two inhibitors differed in sequence by only five amino acid replacements, Asp-3 to Arg; Tyr-17 to Arg; Leu-25 to Arg; Gln-32 to Glu; and Arg-52 to His, in the 57 residue peptide chain. Comparing the amino acid sequences of these two cobra venom inhibitors with those of Russell's viper venom inhibitor II and bovine pancreatic trypsin inhibitor (BPTI), about 50% homology was found in their sequences. The 6 half-cystinyl residues of these inhibitors were in the same linear positions. Moreover, the regions which are structurally and functionally important in the well-known BPTI molecule were found with extremely high sequence homology in the cobra venom inhibitors. These findings strongly suggest that the cobra venom inhibitors as well as Russell's viper inhibitor II have very similar conformations to that established for BPTI.
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PMID:Snake venom proteinase inhibitors. III. Isolation of five polypeptide inhibitors from the venoms of Hemachatus haemachatus (Ringhal's corbra) and Naja nivea (Cape cobra) and the complete amino acid sequences of two of them. 95 Mar 37

Of four glycoproteins isolated from guinea pig testes, two were aspermatogenic (types I and IV) and two (types II and III) were inactive. The glycoproteins were rich in carbohydrate, varying from 41.5% to 49.5% carbohydrate by weight. Each glycoprotein had a unique amino acid composition, but in general low levels of tyrosine, tryptophan, and basic amino acids were found along with relatively high contents of serine, threonine, glutamic acid, and proline. Types I and IV glycoproteins were remarkably stable; their aspermatogenic activity was not affected by urea, trypsin, or heating at 100 degrees C in water or in 1 M HCl for 15 min. Carbohydrate analysis revealed little difference in the monosaccharide compositions of types I and IV glycoproteins, except that only the type I contained sialic acid. In contrast, types II and III glycoproteins lacked sialicacid and fucose and contained much less mannose. Both N-acetylglucosamine and N-acetylgalactosamine were present in all four glycoproteins, and they dominated in the types II and III. Fucose and at least 20-25% of the galactose appeared to occupy terminal positions in type IV glycoprotein as shown by their release after 15 min hydrolysis in 1 M HCl. All of the glycoproteins contained a relatively high percentage of galactose by weight, from 12.6 to 19.3%. The molecular weights of the glycoproteins were estimated by sodium dodecyl sulfate gel electrophoresis to be 47000, 105000 and 18000 respectively for the types I, II, and IV; type III glycoprotein showed two major bands, with molecular weights of 41500 and 22800. All the above molecular weight values are probably overestimated because of high carbohydrate content. The molecular weight of type IV glycoprotein was found to be 13000 by ultracentrifugation; a corrected value of 29000 was calculated for type I glycoprotein.
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PMID:Experimental allergic aspermatogenic orchitis. IV. Chemical properties of sperm glycoproteins isolated from guinea pig testes. 95 93

1. The preliminary phytochemical screening of the two seeds established the presence of carbohydrates and/or glycosides, flavnoids, unsaturated sterols and/or triterpenes, saponins, trypsin inhibitors and haemagglutinins. In addition, it established the absence of cardenolides, tannins, alkaloids and oxidase enzyme. 2. Certain pharmacopoeial constants, including moisture, ash, acid-insoluble ash, water-soluble ash and crude fibre were determined. 3. The two seeds were subjected to successive extractions with different organic solvents such as petroleum ether (50-70 degrees C), diethyl ether, chloroform and ethyl alcohol. The successive yields of extractives were determined. Examination of the crude extracts showed that petroleum ether extract contained sterols and/or triterpenes, while ether, chloroform, and ethyl alcohol extracts contained reducing substances. 4. General analysis of the two seeds for proteins, fats, carbohydrates, fibre and ash contents were carried out and the results were given in g/100 g dry seeds. Pigeon pea contained 25.2 g protein, 170 mg calcium and 8.9 mg iron. The protein content of kidney bean was 23 g, while calcium and iron contents were 134 mg and 8.02 mg respectively. 5. Extractions of the proteins using different solvents such as cold water, hot water, saline buffer pH 7 and sodium hydroxide was the best extractant. 6. The amino-acid content of the two seeds, whether raw or cooked, showed that they were deficient in methionine, cystine and tryptophan. Other essential amino acids were present in amounts higher than that given by the FAO provisional pattern. 7. Cooking the seeds by the popular methods used in the country resulted in an increase in the amounts of the amino acids, threonine, leucine and isoleucine, while the other amino acids present remained unchanged or decreased. It was also observed that cooking the seeds destroyed the trypsin inhibitors and haemagglutinins found in the two seeds.
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PMID:Phytochemical and nutritional studies on pigeon pea and kidney bean cultivated in Egypt. 96 10

The enzymic hydrolysis of some proteins (insulin-B-chain-S-sulfonate, S-aminoethylated lysozyme, bovine serum albumin) by immobilized peptidolytic enzymes is reported. Sepharose-bound pronase, trypsin and a protease from Thermoactinomyces sp. (MP), the latter both cross linked by glutaric dialdehyde and an exopeptidase mixture containing Sepharose-bound leucine aminopeptidase, carboxypeptidase A and a crude preparation of prolidase were used. After enzymic hydrolysis nearly all amino acids, except proline, were recovered in a 100% yield compared to the value of an acid reference hydrolysate. Tryptophan and methionine, which are partially destroyed by acid hydrolysis in the presence of oxygen could be recovered completely.
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PMID:[Protein hydrolysis by immobilized enzymes]. 98 21

1. The proximate analysis of raw Syrian lentils (Lens esculentus), variety red chick pea (Cicer arietinum) variety balady, has been made. The protein content of the two raw seeds were 23 and 22 g% for lentils and chick peas, respectively. Ethereal extract, fiber, ash, calcium, phosphorus and iron content of the two raw seeds have been also assayed. 2. The levels of most of the amino acids were also estimated in the raw and cooked seeds. It was found that tryptophan- and sulphur-containing amino acids were the most limiting ones. Cooking the seeds by the same methods commonly used in Syria resulted in the loss of most of the amino acids, with the exception of lysine and tryptophan which were slightly increased. 3. Trypsin inhibitors and saponins were detected in the raw seeds. Haemagglutinins were present in raw lentils only. Cooking the seeds destroyed the trypsin inhibitors and haemagglutinins and did not affect the saponins. 4. The net protein utilization of whole lentils and chick peas were 38 and 53, respectively. Decortication of lentils or cooking without decortication has no effect on the NPU values. Cooking the decorticated lentil seeds raised its NPU values from 38 to 56. Cooking chick peas resulted in a slight increase in their NPU. Supplementation of the raw and treated seeds with methionine and tryptophan raised its NPU values markedly.
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PMID:Nutritive studies on some raw and prepared leguminous seeds commonly used in the Arab Republic of Syria. 102 Mar 73

A trypsin inhibitor was isolated as a homogenous protein from the seeds of guapuruvu-tree (Schizolobium parahyba (Vell.) Toledo). In addition to its strong inhibitory activity against trypsin the purified inhibitor presented a lesser activity against alpha-chymotrypsin. The purification of the protein inhibitor was achieved from the crude extract of deffated seeds through ammonium sulphate salting-out, successive chromatographies on Sephadex G-75 and DEAE-Sephadex A-50 columns followed by preparative polyacrylamide-slab electrophoresis. The following properties were presented by the purified inhibitor: molecular weight of 12,000 daltons, as estimated by gel filtration; isoelectric point at pH 5.0 - 5.2, by electrofocusing; combining molar ratio of 1:1 (mole trypsin/mole inhibitor), on the basis of inhibition assay and the molecular weight of 29,800 daltons found for the trypsin-inhibitor complex; A1%1-cm = 4.35, at 275 nm and pH 7.0. The inhibitor presents a high content of cystine (14 cystinyl residues per molecule) and is entirely devoid of methionine, tryptophan and free sulhydryl groups. The fluorescence spectra are typical for tyrosine with a strong quenching of emission indicated by the quantum yield. The circular dichroism spectra suggest a predominantly unordered structure for the inhibitor molecule.
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PMID:Isolation and some properties of a trypsin inhibitor from seeds of Schizolobium parahyba (Vell.) Toledo. 103 93

Several fragments of bovine serum albumin have been isolated following limited tryptic hydrolysis and their positions then determined in the bovine serum albumin sequence published by J. R. Brown ((1975), Fed. Proc., Fed. Am. Soc. Exp. Biol. 34, 591). When bovine serum albumin was coupled to palmityl-aminoethylamino-agarose and digested with trypsin, two fragments were obtained: (a) peptide 115-184, containing the highly aromatic disulfide loop 3 of Brown's model, and (b) a larger fragment, residues 377-581, containing disulfide loops 7-9. This fragment constitutes the third of the three domains of the albumin molecule. From bovine serum albumin digested in solution, peptide 115-184 was again obtained, as well as (c) a 39,000-dalton fragment identified as residues 198-581, loops 4-9 of the second and third domains, but with a long, tryptophan-containing segment 204-238 missing from loop 4. The ability to isolate these fragments without cleaving disulfide bridges is partial confirmation of the proposed model of bovine serum albumin as a series of nine independent loops.
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PMID:Fragments of bovine serum albumin produced by limited proteolysis. Isolation and characterization of tryptic fragments. 109 43


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