Purity >95%. There is a ninth member of the mammalian UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (ppGaNTase) family;termed ppGaNTase-T9. This enzyme is expressed in a broadly distributed manner across many adult tissues. Significant levels of 5- and 4.2-kilobase transcripts were found in rat sublingual gland;testis;small intestine;colon;and ovary;with lesser amounts in heart;brain;spleen;lung;stomach;cervix;and uterus. In situ hybridization to mouse embryos (embryonic day 14.5) revealed significant hybridization in the developing mandible;maxilla;intestine;and mesencephalic ventricle. Constructs expressing this gene transiently in COS7 cells resulted in no detectable transferase activity in vitro against a panel of unmodified peptides;including MUC5AC (GTTPSPVPTTSTTSAP) and EA2 (PTTDSTTPAPTTK).However;when incubated with MUC5AC and EA2 glycopeptides (obtained by the prior action of ppGaNTase-T1);additional incorporation of GalNAc was achieved;resulting in new hydroxyamino acid modification. The activity of this glycopeptide transferase is distinguished from that of ppGaNTase-T7 in that it forms a tetra-glycopeptide species from the MUC5AC tri-glycopeptide substrate;whereas ppGaNTase-T7 forms a hexa-glycopeptide species.