[Hydrogen peroxide for disulfide bridge formation in the synthesis of peptides with the sequence of the immunodominant epitope of HIV gp41 glycoprotein].

A simple, rapid, and highly efficient method for intramolecular disulfide formation in tryptophan-containing peptides using hydrogen peroxide was elaborated. Solid phase synthesis of the peptide fragment corresponding to 601-617 sequence of transmembrane gp41 glycoprotein of HIV-1 was performed by Fmoc-technique. Coupling of Fmoc-Asn-OH by DCC-HOBt method was shown to be accompanied by a side reaction of dehydration of asparagine amide function with the formation of side product (22%) containing 3-cyanoalanine residue. This side reaction was not observed, when Fmoc-Asn-OH was coupled in the form of its p-nitrophenyl ester and with HOBt as a catalyst.