124882-74-2Relevant articles and documents
Action of Serine Carboxypeptidases on Endopeptidase Substrates, N-Acyldipeptideamides
Kunugi, Shigeru,Tanabe, Kazuo,Yamashita, Kouji,Fukuda, Mitsuhiro
, p. 1399 - 1402 (1987)
Action patterns of two serine carboxypeptidases, one from yeast (Y) and the other from wheat bran (W), on N--(Fua-)-dipeptideamide substrates were examined by HPLC and amino acid analysis.In the reaction of the wheat enzyme the substrates were hydrolyzed to Fua-amino acid and no sufficient amount of Fua-dipeptides were detected on HPLC in the product mixtures.Very few or no free amino acids were observed by amino acid analysis.This indicates that the wheat enzyme exhibited carboxamidopeptidase activity on these substrates.On the contrary, carboxypeptidase Y gave Fua-amino acids and Fua-dipeptides as products, depending on the structure of the substrates.Accordingly, liberations of free amino acids were detected in some cases.This result shows that the yeast enzyme acts on some of the substrates in a two step manner: First by amidase and second by a carboxypeptidase activity.Based on these results the substrate binding mechanisms of these enzymes are discussed.
Mechanism of Dipeptidyl Carboxypeptidase Activity of Thermolysin
Fukuda, Mitsuhiro,Kunugi, Shigeru
, p. 2965 - 2970 (1984)
Steady state and presteady state kinetic analyses were performed for thermolysin-catalysed hydrolysis of chromophoric tripeptide substrates with free carboxyl terminal.The pH dependence of kcat showed fairly higher pKa (ca.7) than that of the second-order rate parameter (kcat/Km)(ca.5) and the pH-dependence of Km resembled that of Ki for N-blocked dipeptidyl inhibitor observed before (S.Kunigi et al.Eur.J.Biochem. 124, 157 (1982)).These findings indicated that the reaction with this type of substrate involves a nonproductive binding mode.In a presteady state kinetic study by stopped-flow method, a burst process of 10-20 ms order was observed before the linear steady state at a relatively low pH and temperature.This process showed moderate pH dependence.Considering these experimental results coupled with those accumulated so far on this enzyme, a unified mechanism including a nonproductive binding and an isomerization process in prior to the cleavage of the peptide bond was proposed for the dipeptidyl carboxypeptidase activity of this enzyme.
METABOLISM AND EXCRETION OF FURFURAL IN THE RAT AND MOUSE
Parkash, M. K.,Caldwell, J.
, p. 887 - 896 (1994)
The fate of furfural (2-furancarboxaldehyde) was investigated in male and female Fischer 344 (F344) rats given single oral doses of 1, 10 and 60 mg/kg and male and female CD1 mice given 1, 20 and 200 mg/kg furfural. There was a very high recovery (more than 90 percent of dose) of radioactivity in all dose groups in 72 hr. The major route of elimination was by the urine, with much smaller amounts present in the faeces and exhaled as 14CO2. The residue in the carcass after 72 hr was less than 1 percent of the administered dose. Furoylglycine and furanacryloylglycine were identified as the major urinary metabolites by high-performance thin-layer chromatography, radio-HPLC, gas chromatography-mass spectrometry and 1H-nuclear magnetic resonance spectroscopy, by comparison with synthetic reference compounds. There were only subtle differences in the metabolic profile as a function of dose size, sex and species. An additional minor polar metabolite was excreted by male rats and mice, and the parent acids of the glycine conjugates were excreted at the higher doses. The results are discussed in terms of the participation of xenobiotics in the chain elongation reactions of fatty acid biosynthesis.
Preparation and synthetic applications of N-(α,β-unsaturated acyl)-α-amino acid derivatives
Katritzky, Alan R.,Gyanda, Reena,Meher, Nabin K.,Song, Yuming
experimental part, p. 1249 - 1259 (2010/10/03)
N-(α,β-Unsaturated acyl)-α-amino acids, amides and esters are structural motifs of many biologically active natural products. An alternate and advantageous approach for the synthesis of N-(α,β-unsaturated acyl)-α-amino acid derivatives is developed via ac
Efficient peptide coupling method of conjugated carboxylic acids with methyl ester amino acids hydrochloride. Application to the synthesis of Fa-Met, an important enzymatic substrate
Michel Brunel, Jean,Salmi, Chanaz,Letourneux, Yves
, p. 217 - 220 (2007/10/03)
Benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate reagent (BOP) serves as an efficient and versatile coupling reagent for the coupling of conjugated carboxylic acid with methyl ester amino acids hydrochloride allowing the synthesis of various substituted amino acid derivatives in high chemical yields of up to 90%. The usefulness of this method is illustrated in the synthesis of Fa-Met, an important enzymatic substrate.
Protease-Catalyzed Peptide Formation under High Pressure
Kunugi, Shigeru,Tanabe, Kazuo,Yamashita, Kouji,Morikawa, Yoshio,Ito, Takanobu,et al.
, p. 514 - 518 (2007/10/02)
The effect of high pressure on peptide formation by the catalysis of carboxypeptidase Y (substitution of ester or peptide by amino acid derivative) or by thermolysin (condensation of N-acylamino acid and amino acid amide) was studied.The carboxypeptidase Y-catalyzed substitution reaction of N-phenylalanine ethyl ester with glycinamide or phenylalaninamide showed a six-fold higher total peptide yield at 200 MPa than at atmospheric pressure.In the case of the reaction of N-acyldipeptide and amino acid amide, both the peptide yield and substitution efficiency were improved at elevated pressure and the wasteful hydrolysis of the substrate was highly depressed by increasing pressure.The pressure was also effective to get rid of the substrate inhibition by the amino acid ester inthe reaction between the N-acylamino acid ester and the amino acid ester and to yield much dipeptide ester at high pressure.An improvement of the peptide yield by pressure for the reaction of thermolysin was observed in a combination of less specific substrates, N-benzyloxycarbonyl-L-aspartic acid and phenylalanine methyl ester, since the high catalytic activity of this enzyme under elevated pressure was significant only in the case that the peptide yield was kinetic-controlled.
Superactivation of thermolysin by acylation with amino acid N-hydroxysuccinimide esters.
Blumberg,Vallee
, p. 2410,2411 (2007/10/05)
Synthesis of a series of active N-hydroxysuccinimide esters of aliphatic and aromatic amino acids has yielded a new class of reagents for the covalent modification of proteolytic enzymes such as thermolysin. The activities of aliphatic acyl amino acid thermolysins are from 1.7 to 3.6 times greater than that of the native enzyme when hydrolyzing durylacryloyl-Gly-Leu-NH2, the substrate employed most widely. By comparison, the aromatic acylamino acid derivatives are "superactive," their activities being as much as 70-fold greater. Apparently, the aromatic character of the amino acid introduced is a critical variable in the determination of the functional response. The increased activity is completely restored to that of the native enzyme by deacylation with nucleophiles, such as hydroxylamine, and the rate of restoration of native activity is a function of the particular acyl group incorporated. Preliminary evidence regarding the chemical properties of the modified enzyme suggests that tyrosine, rather than lysine, histidine, or arginine, may be the residue modified. The functional consequences of successive modification with different reagents, moreover, indicate that each of them reacts with the same protein residue. The competitive inhibitors beta-phenyl-propionyl-Phe and Zn-2+ do not prevent modification with these active esters. Hence, the site(s) of their inhibitory action differ(s) from that at which modification occurs. The structure of the substrate is also a significant variable which determines the rate at which each acyl amino acid thermolysin hydrolyzes peptides. Depending on the particular substrate, the activity of aromatic derivatives can be as much as 400-fold greater than that of the native enzyme, and the resultant activity patterns can be ordered in a series characteristic for each enzyme derivative.
