High-performance liquid chromatographic method for determination of hypusine and deoxyhypusine.

A selective and sensitive reversed-phase high-performance liquid chromatographic method is described for the determination of the amino acid hypusine which occurs ubiquitously in mammalian cells and for the simultaneous measurement of its immediate precursor deoxyhypusine. These amino acids, after their ion-exchange separation from the bulk of other amino acids in protein hydrolysates, are derivatized with o-phthalaldehyde and the fluorescent derivatives are separated by reverse-phase liquid chromatography. The sensitivity of this method allows detection of less than 5 pmol of each of these unusual amino acids. The method is applied to the determination of hypusine and deoxyhypusine in acid hydrolysates of cultured cells and tissues.