Assay of Arginyltransferase Activity by a Fluorescent HPLC Method

Syntheses of fluorescent substrate and product for arginyltransferase, N-aspartyl-N'-dansylamido-1,4-butanediamine (Asp-4DNS), and N-arginylaspartyl-N'-dansylamido-1,4-butanediamine (ArgAsp-4DNS), respectively, including their precursor 4-dansylamidobutylamine (4DNS), are described. Then, HPLC conditions are summarized for a baseline separation of the three compounds in 10 min. The present method, which permits the simultaneous determination of Asp-4DNS, 4DNS, and ArgAsp-4DNS (in eluting order), is advantageous in measuring arginyltransferase activity and detecting the unfavorable enzyme(s) in 105,000 × g supernatant of tissues to ensure accurate determination.