Assay of Arginyltransferase Activity by a Fluorescent HPLC Method

Syntheses of fluorescent substrate and product for arginyltransferase, N-aspartyl-4-dansylamidobutylamine (Asp4DNS) and N-arginylaspartyl-4-dansylamidobutylamine (ArgAsp4DNS), 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 Asp4DNS, 4DNS, and ArgAsp4DNS (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.