AFFINITY ELECTROPHORETIC DETECTION OF PRIMARY AMINO-GROUPS IN NUCLEIC-ACIDS - APPLICATION TO MODIFIED BASES OF TRANSFER-RNA AND TO AMINOCYLATION

Thiolation of primary amino groups in tRNA with the heterobifunctional reagent N-succinimidyl 3-(2-pyridyldithio)propionate gives rise to species which are retarded during electrophoresis in organomercury-containing polyacrylamide gels. Since such amino groups occur, as far as is known, only as part of the modified bases 3-(3-amino-3-carboxypropyl)uridine and N-2-(5-amino-5-carboxypentyl)cytidine or as the α-amino group of aminoacylated tRNAs, this extention of the principle of affinity electrophoresis can be used for the detection and analysis of a specific functional group in both single tRNA species and in a mixed population. The strength of the interaction may be quantified and provides information on the chemical environment/conformation of the derivatized bases. © 1992.