[55] The Chemical Preparation of Acetylaminoacyl-tRNA

This chapter describes the method for the chemical preparation of Acetylaminoacyl-tRNA that is based on the reaction between aminoacyl-tRNA and N-hydroxysuccinimide ester of acetic acid. The active ester is prepared by allowing the acetic acid to react with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide. This method was found to be a general one and has been used successfully with aliphatic carboxylic acids—for example, formic, acetic, caprylic, lauric, and palmitic acids as well as with aromatic compounds containing free carboxylic groups. It was found that when N-hydroxysuccinimide ester of [³H]acetic acid was allowed to react with deacylated tRNA, the radioactivity associated with the tRNA was equivalent to one acetyl residue per 100 molecules of tRNA.