Determining the availability of activated amino acids for solid phase peptide synthesis

Data concerning the reaction characteristics of each amino acid are of fundamental importance for providing optimum reaction conditions and high yields during polypeptide synthesis. Loss of activated amino acid as a function of time would have a pronounced effect on the efficiency of synthesis. An assay procedure is described which quantitatively determines the availability of DCC activated amino acids as a function of preincubation time. The assay was employed to follow the inactivation of t-BOC.Leu(DCC) and indicated a significant loss of activated amino acid.