Amino acid activation with adenosine 5′-phosphorimidazolide

Summary

Amino acids are activated by reaction with adenosine 5′-phosphorimidazolide in aqueous imidazole buffers. If adenosine 5′-(O-methylphosphate), an analogue of the 3′-terminus of t-RNA is present, 2′(3′)-O-aminoacyladenosine 5′-(O-methylphosphate) is formed. Fifteen percent of this compound accumulated at pH 5.8, but less was formed at higher pHs. The highest efficiency of utilization of ImpA attained in our experiments was about 24%. Analogous reactions occured with several other amino acids, including a number that have functional side-chains.