Creative Enzymes accomplished prominent achievements in enzyme activity assays in the past several years due of the establishment of standard protocols and strict quality controls. These advantages are resulted from the thorough expertise development and professional attitude. The extensive experiences accumulated from thousands of finished testing will guide to suitable approaches to activity measurement for each transferase, including polypeptide N-acetylgalactosaminyltransferase.

Polypeptide N-acetylgalactosaminyltransferase (pp-GalNAc-T, EC 2.4.1.40) catalyzes the attachment of a monosaccharide, N-acetylgalactosamine (GalNAc), to the hydroxyl group of serine or threonine residue on a target protein or polypeptide, releasing the UDP molecule. This reaction is an initiate process of the biosynthesis of the O-glycan of glycoprotein. The catalyzed reaction needs the participation of both manganese and calcium ions to act as the cofactors.

The pp-GalNAc-Ts is a large family with many isoforms. To date, 15 human pp-GalNAc-Ts, termed pp-GalNAc-T1 to pp-GalNAc-T15, have been reported. These enzymes are all type II membrane proteins with primary structures that are similar to the others in glycosyltransferases. Biochemical analyses suggest that this domain functions in the transfer of GalNAc to glycopeptide but not to peptide substrates. Due to the main functions in modulating protein processing, this enzyme has huge potentials in drug development, cancer research, and molecular biology. For drug development, this enzyme is significant for insights into O-glycosylation processing and the designation of appropriate mammalian expression systems for recombinant drug glycoproteins. For cancer research, this enzyme is a new tool for the investigation of motif peptide O-glycosylation alterations in pathological situations. For molecular biology, heterologous expression of this enzyme support the studies on in vitro glycosylation. However, the precise results of activity assays are tough tasks due to the lack of proper assay method for specific reaction conditions. Creative Enzymes has large analysis platforms which can meet all research requirements.

Figure: The crystal structure of human pp-GalNAc-T10 with UDP, GalNAc and Mn²⁺.
Reference: Kubota T et al. J Mol Biol. 2006 359(3): 708-27.

Creative Enzymes makes every effort to providing superior services for enzyme activity assays. Our core value of persisting in the best quality has never changed since the foundation of the company. In the future, Creative Enzymes will continue providing the first-in-class assays and grow together with our clients.