[Sterospecific selection of nucleophilic compounds in the chymotrypsin-catalyzed formation of the peptide bonds].
The course of stereospecific selection of nucleophilic compounds was studied in the reaction of acyl-enzymes interaction with razemic substrate-like nucleophiles, e.g. amino acid esters, by measuring optical rotation or incorporation of labelled D-compounds. It was shown that the acyl-enzymes are not responsible for the stereospecific selection of substrate-like nucleophiles. Since stereospecific selection of nucleophiles occurs in some chymotrypsin-catalyzed reactions, such selection may be produced by chymotrypsin till the formation of an acyl-enzyme compound with the substrate at the enzyme-inhibitor stage (or the Michaelis complex) with nucleophilic compounds. Even under the optimal conditions no absolute stereospecific selection of nucleophiles occurred, as was observed in case of a substrate (a donor of the acyl amino acid residue), undergoing degradation. An essential role of a specific site of nucleophile binding in the reactions of chymotrypsin-catalyzed peptide bond formation, is emphasized.
D000596:Amino Acids / Q000378:metabolism; D001665:Binding Sites; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010452:Peptide Biosynthesis; D013329:Structure-Activity Relationship
D000596:Amino Acids; D002918:Chymotrypsin
Stereospetsifichnyĭ otbor nukleofil'nykh soedineniĭ v kataliziruemykh khimotrilsinom reaktsiiakh obrazovaniia peptidnoi sviazi