Chemo-enzymatic synthesis of the tripeptide RGD in organic solvents

摘要

Arg-Gly-Asp(RGD), a characteristic tripeptide sequence within fibronectin has been attracting much attention of investigators since it was proved to be a recognition site for cellular adhesion, spreading and motility of cells. RGD and some synthetic RGD-containing peptides as competitive, reversible inhibitors for fibronectin binding have been used to study adhesive interaction between cells and inhibit tumor metastasis and platelet aggregation. Many hydrophobic small peptides were synthesized in high yield using proteases. However, because of the low solubility of hydrophilic amino acids in organic solvents, the synthesis of hydrophilic amino acid-containing peptides generally proceeds in a rather low yield. RGD tripeptide contains two hydrophilic amino acids (Arg and Asp) and a neutral one. A new strategy to solve the problem posed above for synthesis of RGD was taken in this study. Chemo-enzymatic synthesis of the tripeptide RGD was conducted in this study. First of all, free dipeptide, Gly-Asp was synthesized by a novel chemical method only using glycine. Then, RGD tripeptide was synthesized by an enzymatic method in organic solvents with reasonable vield.