Property and function of cell surface glycosyltransferases

Since a galactosyltransferase was first reported to be on the mammalian cell surface in the early 1970s, different classes of glycosyltransferase have been detected on the cell surface of various types of cell by enzymatic or immunological analysis. Although these surface enzymes are identical in catalytic property to those found in Golgi apparatus or endoplasmic reticulum where they are involved in biosynthesis of glycoconjugates, there obtained a monoclonal antibody that distinguishes these enzymes localized differently, and observed some differences in their protein chemistry and in their amounts expressed during cellular differentiation. Due to no availability of sugar donor intercellulary, the surface glycosyltransferases are participating in cellular interactions by recognizing and binding to the appropriate substrates on opposing cell surfaces and extracellular matrices, without showing any enzyme catalysis.