Quantitative enzymatic hydrolysis of tRNAs: reversed-phase high-performance liquid chromatography of tRNA nucleosides.

A rapid quantitative method for enzymatic hydrolysis of microgram amounts of tRNA has been developed, specifically to take full advantage of our precise, accurate, and selective reversed-phase high-performance liquid chromatographic (HPLC) system for separation and measurement of the major and modified nucleosides in tRNA. After study of several enzyme systems, nuclease P1 and bacterial alkaline phosphatase were selected and the hydrolysis parameters were systematically studied. Optimized hydrolysis conditions give quantitative hydrolysis in 2 h and this short incubation time prevents loss of unstable nucleosides. The chromatographic system can tolerate relatively high levels of protein in the sample allowing high enzyme--substrate ratios and direct injection of hydrolysates. This enzymatic hydrolysis--HPLC method is the best described to date for quantitative determination of the nucleoside composition of tRNAs and has already provided important information for investigation of the role of modification in the function of RNAs.