ST3Gal1, soluble fragment, Human Recombinant

ST3Gal1 catalyzes transfer of the sialic acid Neu5Ac from CMP-Neu5Ac (cytidine 5'-monophosphono-N-acetylneuraminic acid) to Galβ1, 3GalNAc on glycoproteins or glycolipids in an α2, 3 linkage. It is a type II transmembrane protein that is normally localized to the golgi, but can be cleaved to yield a soluble product. Sialylation of the core-1 structure (Galβ1, 3GalNAc-O-Ser/Thr) by ST3Gal1 prevents formation of the core-2 structure (GlcNAcβ1, 6(Galβ1, 3)GalNAc-Ser/Thr). On CD8+ T-cells this prevents induction of either apoptosis or differentiation into memory cells. Overexpression of ST3Gal1 in breast cancer cells correlated with the presence of the core-1 based marker SM3, whereas healthy cells displayed a higher ratio of core-2 based epitopes. Overexpression of ST3Gal1 in colorectal carcinoma was found to be related to poor patient survival.