Interaction of chlorambucil with tRNA

Abstract
Preincubation of purified mixed tRNAs from Escherichia coli K12-MO with 2.94 mM chlorambucil (CAB [an antitumor and immunosuppressant agent]) for 2 h at 37.degree. C results in the inhibition of the capacity of mixed tRNA to accept alanine, arginine, asparagine, aspartic acid, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine and valine by 100, 71, 100, 100, 100, 95, 32, 88, 36, 26, 96, 78, 44, 31, 34, 98, 38 and 17%, respectively. Preincubation of tRNA with 0.75 mM and 0.29 mM CAB inhibited aminoacylation by aspartic acid to the extent of 69 and 17% respectively. CAB has no apparent effect upon the capacity of ATP to function in the formation of aminoacylated tRNALeu.