BF3-methanol as a cyclization/cleavage/conversion reagent for suppression of amino acid racemization in Edman sequencing and L-configuration determination method

A modified Edman procedure using phenylisothiocyanate (PITC) and boron trif luoride (BF3)-methanol for amino acid sequencing and D/L configuration dete rmination was developed. The utilization of BF3-methanol solution resulted in the direct generation of phenylthiohydantoin (PTH)-amino acids from phen ylthiocarbamoyl (PTC)-peptide excluding the extraction step after cyclizati on/cleavage reaction. B-3-methanol as a cyclization/cleavage/conversion rea gent in the Edman sequencing procedure afforded a great suppression of the racemization of liberated PTH-amino acids avoiding the extraction step. (C) 2001 Elsevier Science B.V. All rights reserved.