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)

Insoluble elastin from copper-deficient animals has an amino acid composition intermediate between mature elastin and salt-soluble elastin (a higher lysine content and correspondingly low number of cross-links relative to the normal protein) and is solubilized by successive treatment with trypsin and chymotrypsin at 4 and 37 degrees C. Small amounts of B3H4 (11 mg--2 g of elastin) reduced allysine, allysine aldol, dehydronorleucine, and dehydromerodesmosine in insoluble elastin from copper-deficient pig aorta. In contrast, desmosine and isodesmosine were reduced only when a large excess of reductant (400 mg borohydride) was included in the reaction mixture. Reduction studies indicated that lysinonorleucine and merodesmosine were present in their dehydro forms to a greater extent in copper-deficient pig elastin than in normal elastin. After reduction with borohydride approximately 35% of the reduced form of the insoluble elastin remained insoluble after digestion with trypsin and chymotrypsin. A peptide containing the aldehyde oxidation product of lysine (allysine) and demonstrating an enrichment in glutamic acid was purified from the reduced form of copper-deficient pig elastin and partially sequenced. Its sequence (Gly-Ala-Glu-allysine-(Glu)...) and amino acid composition suggest: (1) clustering of glutamic acid residues in the elastin molecule, and (2) that allysine residues are not restricted to the alanine-enriched sites described for other elastin cross-links. Insoluble elastin from copper-deficient animals promises to be a useful tool for elastin sequence studies.
...
PMID:Characterization of insoluble elastin from copper-deficient pigs. Its usefulness in elastin sequence studies. 42 11

The inactive 50,000-dalton fragment of human plasma alpha1-proteinase inhibitor resulting from limited proteolysis of the inhibitor by Crotalus adamanteus proteinase II has been isolated and partially characterized. The amino acid composition of the inactivated inhibitor indicates the loss of a peptide fragment from the intact inhibitor. Both intact and inactivated inhibitor contain COOH-terminal lysine. However, the NH2 terminus of the intact inhibitor is Glx, whereas that of inactivated inhibitor is methionine. NH2-terminal analysis of the inactive inhibitor fragment revealed the following sequence: -Met-Phe-Leu-Glu-Ala-Ile-Pro-Met-Ser-Ile-Pro-Pro-Gln-Val-Lys-Phe-Asn. The data show that the venom proteinase has inactivated alpha1- proteinase inhibitor by cleavage of a single bond which differs from that reported for trypsin or papain.
...
PMID:Characterization of the inactive fragment resulting from limited proteolysis of human alpha1-proteinase inhibitor by Crotalus adamanteus proteinase II. 44 52

The primary structure of the membrane-binding segment of rabbit cytochrome b5 has been determined. This segment, prepared by trypsin digestion of the intact protein, consists of 43 amino acid residues and corresponds to the COOH-terminal end (residues 91-133) of the parent molecule. Deduction of the primary structure was based on automated sequence analysis of the whole segment as well as manual and dansyl-Edman degradations of peptide fragments produced by CNBr cleavage and partial acid hydrolysis. The sequence obtained is: Leu-Ser-Lys-Pro-Met-Glu-Thr-Leu-Ile-Thr-Thr-Val-Asn-Ser-Asn-Ser-Ser-Trp-Trp-Thr-Asn-Trp-Val-Ile-Pro-Ala-Ile-Ser-Ala-Leu-Ile-Val-Ala-Leu-Met-Tyr-Arg-Leu-Tyr-Met-Ala-Asp-Asp. This sequence is 63 to 81% homologous with respect to those determined for the membrane-binding segments of equine, porcine and bovine cytochrome b5. The interaction of this segment with phospholipid bilayer membranes is discussed, and a prediction of its secondary structure is also presented.
...
PMID:Primary structure of the membrane-binding segment of rabbit cytochrome b5. 50 May 81

We present in this paper the sequence of the heme-binding domain of chicken sulfite oxidase which can be obtained by chymotryptic digestion of the native enzyme. The results of an automatic degradation have been reported previously. In the present work peptides were obtained from the heme-binding domain by digestion with trypsin, chymotrypsin and Staphylococcus aureus V8 protease; they were manually sequenced by the dansyl/Edman procedure. The evidence thus obtained is sufficient to completely establish the order of the 97 residues. In addition, two rounds of Edman degradation on sulfite oxidase itself allowed us to identify the same two residues, H-Ala-Pro, present at the N-terminus of the heme-binding domain; this result suggests that the latter constitutes the amino-terminal end of the sulfite oxidase peptide chain. The data presented here confirm the strong similarity between sulfite oxidase and microsomal cytochrome b5 already suggested by our first results. A sequence alignment is proposed for the two proteins. Inspection of the calf liver cytochrome b5 three-dimensional model together with the alignment suggests a similar overall structure for sulfite oxidase core with a limited number of backbone modifications. Our results point to a common evolutionary origin for sulfite oxidase core and microsomal cytochrome b5.
...
PMID:Amino acid sequence of the 'b5-like' heme-binding domain from chicken sulfite oxidase. 51 Feb 90

Alanine-neochymotrypsinogen was prepared by incubating 20 parts bovine pancreas chymotrypsinogen A with one part alpha-chymotrypsin in a solution containing 1 M (NH4)2SO4, 0.1 M sodium acetate, 0.05 M Tris buffer (pH 8.0) and 0.5 mg/ml soybean trypsin inhibitor. Optimal yields of NH2-terminal alanine were obtained after 60 h incubation at 4 degrees C. Ala-neochymotrypsinogen was isolated from the reaction mixture by affinity chromatography and ion-exchange chromatography on carboxymethyl-cellulose. As expected, the purified preparation was enzymatically inactive and, compared to chymotrypsinogen, had one additional NH2-terminal group identified as alanine. Ala-neochymotrypsinogen was activated by incubating with trypsin at a zymogen : trypsin ratio of 30 : 1 in 0.1 M phosphate buffer, pH 7.6 at 4 degrees C for 1 h. The fully active, stable species was identified as alpha-chymotrypsin.
...
PMID:On the activation of bovine chymotrypsinogen A. Preparation of alanine-neochymotrypsinogen and its activation to alpha-chymotrypsin. 56 99

Insulin hexamethyl ester was digested by trypsin. The resulting desoctapeptide-(B23 - 30)-insulin pentamethyl ester was purified. This compound was digested by carboxypeptidase B to remove the arginine residue B22 at the end of the B chain. Then the N-terminal amino groups of the remaining desnonapeptide-(B22 - 30)-insulin pentamethyl ester were protected with the Boc residue. The free carboxyl group of the glutamic acid residue B21 of this product was coupled to the following synthetic tetrapeptide esters: Arg-Gly-Phe-Phe-OMe, Lys(Boc)-Gly-Phe-Phe-OMe, Orn(Boc)-Gly-Phe-Phe-OMe, Cit-Gly-Phe-Phe-OMe, Ala-Gly-Phe-Phe-OMe and Gly-Gly-Phe-Phe-OMe. The syntheses of these peptide esters are described. After removal of all protecting groups, despentapeptide-insulin (B22-Arg) and analogues of this product with variation in position B22 could be obtained. They were purified by column chromatography. The biological activities of these components were determined by the mouse fall test. In the case of despentapeptide insulin (C-terminus Arg-Gly-Phe-Phe), the activity rose to the expected value of 34%. The insulin variants with amino acid residues other than arginine in position B22 had much lower activities: with lysine 13%, with ornithine 12%, with citrulline 9%, with alanine 8% and with glycine 6%. Desnonapeptide-insulin by itself posses an activity of 3%. These results demonstrate once more the essential nature of arginine residue B22 for insulin activity.
...
PMID:Structure and activity of insulin, XV[1-5]. Further evidence for the importance of arginine residue B22 in the activity of insulin. Semisyntheses of despentapeptide-(B23 - 30)-insulins varied in B22 using desnonapeptide-(B22 - 30)-insulin and tetrapeptides. 59 Sep 40

In order to study the mechanism of substrate binding of trypsin by affinity chromatography, we synthesized various L-arginine-terminated oligopeptides having different chain length and amino acid sequences, and immobilized them on agarose gel. The interaction of beta-trypsin with these adsorbents was studied by a quantitative affinity chromatographic procedure which gave the dissociation constant (Kd) of the trypsin-immobilized ligand complex. This procedure proved to be very useful and to give information equivalent to that obtained by kinetic procedures. The contribution of the amino acid residue at P2 of the ligands to the affinity was studied by using tripeptide (Gly-X-Arg) Sepharoses, and alanine was found to be more effective than glycine or valine. This conclusion was supported by a kinetic experiment in which Ki values of the corresponding soluble tripeptides (Ac-Gly-X-Arg) were determined. A significant decrease in Kd was observed when the ligand was elongated from dipeptide to tripeptide. However, Kd decreased only slightly when the ligand was elongated further. This suggests that a tripeptide is sufficiently long as a ligand. On the basis of these results, the mode of substrate binding of trypsin is discussed.
...
PMID:Affinity chromatography of trypsin and related enzymes. IV. Quantitative comparison of affinity adsorbents containing various arginine peptides. 59 12

Aspartate transaminase from chicken heart cytosol was immobilized covalently on activated thiol-Sepharose and digested with trypsin. After washing, the thiol-containing peptides were eluted with 2-mercaptoethanol and further purified by gel-filtration and paper chromatography. Three pure cysteinyl peptides were isolated. One of them may be represented as Ile-(Asp, Met, Cys, Gly, Leu, Thr2)-Lys; this peptide is identical to the fragment comprizing residues 387--395 in the peptide chain of aspartate transaminase from pig heart cytosol. It thus contains a cysteine residue homologous to Cys-390 of the pig heart enzyme. The second cysteinyl peptide had the following composition and partial sequence: Tyr-Phe-Val-Ser-Glu-Gly-Phe-Glu-Leu-Phe (Cys, Ala, Glu, Ser2, Phe)Lys, which corresponds to the sequence 242--258 of the pig enzyme and thus contains a cysteine residue homologous to Cys-252. The third cysteinyl peptide was similar to the tryptic peptide of the pig enzyme containing Cys-191.
...
PMID:[Thiol peptides from the aspartate transaminase of chicken heart cytosol]. 59 23

Soybean inhibitor C-II, which inhibits trypsin, alpha-chymotrypsin, and elastase, was reduced and S-carboxymethylated, and digested with trypsin. The amino acid sequences of the resulting tryptic peptides were determined by conventional methods, establishing the complete 76-amino acid sequence of the inhibitor. Inhibitor C-II was found to be homologous with soybean (Glycine max) Bowman-Birk inhibitor and more closely related to an inhibitor from garden beans (Phaseolus vulgaris). The homology with these inhibitors and the limited proteolysis of C-II indicated the reactive sites of C-II for elastase and trypsin to be alanine-22 and arginine-49, respectively. Arginine-49 was also identified as a reactive site for alpha-chymotrypsin. It was found that only a few replacements of one or two amino acid residues around the reactive sites resulted in considerable alteration of the inhibitory specificity.
...
PMID:Studies on soybean trypsin inhibitors. XI. Complete amino acid sequence of a soybean trypsin-chymotrypsin-elastase inhibitor, C-II. 59 41

The kinetic parameters Km and k cat/K m have been determined for the carboxypeptidase B (CPB, EC 3.4.12.3) catalyzed hydrolysis of benzoylglycyl-DL-homolysine and benzoylglycyl-L-homorginine. Plots of these data and those for Bz-Gly-Orn and Bz-Gly-Arg (Wolff, E. C., Schirmer, E.W. & Folk, J. E. (1962) J. Biol. Chem. 237, 3094-3099) and Bz-Gly-Lys versus the length of the side chain of the basic amino acid indicate that unlike trypsin (EC 3.4.21.4) (Seely, J. H. & Benoiton, N. L. (1970) Can. J. Biochem. 48, 1122-1131) CPB has a higher bending affinity for a guanidino group than for an amino group at the side chain of the substrate C-terminus. On the other hand, CPB is similar to trypsin (ibid) in that the best substrate would have a side chain length between those of lysine and arginine. Studies with Bz-MeGly-Lys and Bz-Ala-Lys showed that the former is very slowly hydrolyzed by CPB but that the latter is a good substrate with a high affinity for the enzyme, indicative of considerable participation of the Calpha-methyl group of alanine in the binding of the substrate to the enzyme.
...
PMID:Effect of the basic amino-acid side chain length and the penultimate residue on the hydrolysis of benzoldipeptides by carboxypeptidase B. 66 83


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

---