| Abstract: | ABSTRACT Serum albumins are known to catalyze the hydrolysis of aryl esters. Both human and bovine albumins are active against Naphthol AS acetate, resulting in a fluorescence excited at 320 nm and monitored at 500 nm. HSA was more active than BSA. At pH 8.0 the reaction is activated by cetyltrimethylammonium bromide. Other esterases in serum require either calcium or a higher pH for activity. The assay is conducted with albumin diluted to about 10?7 M or less, thus dissociating many potentially interfering ligands. Palmitic acid did not interfere. The interference by bilirubin is minimized by using highly dilute albumin. The present method gives results with serum which correlate well with the widely used Bromcresol Green method. Limit of detection for HSA is 14 picomoles. |
