title: Alcalase-catalysed synthesis of the precursor tetrapeptide N-benzoylarginylglycylaspartylserinamide (Bz-RGDS-NH2) of the cell-adhesion peptide arginylglycylaspartylserine (RGDS).
abstract: In the present study, a precursor tetrapeptide Bz-RGDS-NH2 (N-benzoylarginylglycylaspartylserinamide) of cell-adhesion peptide RGDS (arginylglycylaspartylserine) was synthesized by a novel route. First of all, the precursor tripeptide GDS-NH2 (glycylaspartylserinamide) was synthesized by a chemical method only using aspartic acid and serine at gram scale in four steps. The linkage of the fourth amino acid Bz-Arg-OEt (N-benzoyl-L-arginine ethyl ester) to GDS-NH2 was completed by an enzymatic method under kinetic control in water-miscible organic media. An industrial alkaline protease, Alcalase, with a wide substrate specificity, was used as the catalyst. The effects of organic solvents, pH value, reaction temperature, water content and molar ratio of substrates on the yield of Bz-RGDS-NH2 synthesis were examined. The optimum reaction conditions were found to be pH 10.0, 35 degrees C, 8 h, in an acetonitrile/(Na2CO3/NaHCO3) buffer system (93:7, v/v) with a maximal yield of 65.2%. We found that secondary hydrolysis of the peptide product did not take place in these water-miscible organic solvents.
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University, Changchun 130021, People's Republic of China.
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Huang
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.forename: Yu
authors.initials: Y
authors.lastname: Cai
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Gui
authors.initials: G
authors.lastname: Gao
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Wu
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Xue-Zhong
authors.initials: XZ
authors.lastname: Zhang
mesh_terms: D002384:Catalysis; D002448:Cell Adhesion; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism*; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013379:Substrate Specificity; D013381:Subtilisins / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C533921:N-benzoylarginylglycylaspartylserinamide; D009842:Oligopeptides; D012997:Solvents; D014867:Water; C046617:arginyl-glycyl-aspartyl-serine; D013381:Subtilisins