Assay of rat brain sialyltransferase activities on thin-layer plate

A modified method for measuring the activities of glycosyltransferases using highperformance thin-layer chromatographic (HPTLC) plates is described. In this method a mixture of glycosphingolipid acceptors were chromatographed on a silica gel coated plate and were incubated with the enzyme solution and an appropriate radio-active sugar nucleotide donor. Following incubation, the plate was washed with a buffer and the radiolabeled reaction products on the plate were scrapped off and the radioactivities determined using a liquid scintillation counter. Alternatively, the plate could be exposed to an X-ray film to reveal the radioactive products. This method was used to assay the activities of rat brain cytidine 5’-monophosphate-N-acetylneuraminic acid: LacCer-, GM3-, GM1-, or GD3-sialyltransferases. We found that this method was sensitive, fast and reliable and was capable of assaying.