AffiASSAY® Sialyltransferase Activity Assay Kit (Fluorometric)

Overview

Sialyltransferases (ST, Galactosyldiacylglycerol alpha-2,3-sialyltransferase; 2.4.99.5) belong to the glycosyltransferase family and are expressed in a variety of organisms from bacteria to higher mammals. Previously, it was believed to be not expressed in plants, but sialyltransferase like proteins have been recently identified in rice. STs catalyze the transfer of sialic acid (a kind of N-acetylneuraminic acid) from CMP-Neu5Ac moieties to sugar molecules on the terminal regions of glycolipids and glycoproteins. In higher animals, terminal sialic acid residue-containing glycoconjugates have various important functions including modulation of the immune system, brain development, etc. In bacteria, they play a role in virulence and are present on the bacterial surface to protect them from the immune system. AffiGEN’s Sialyltransferase Activity Assay Kit is a simple, two-step plate based assay that measures the fluorescent product at Ex/Em = 410/470 nm. The assay consists of three enzymatic steps leading to the generation of ammonia. Ammonia then reacts with the detection reagent to form a fluorescent product measured at Ex/Em = 410/470 nm. The kit can detect activity from both α-1,6 and α-2,6 sialyltransferases and can measure as low as 20 μU ST activity under assay conditions.