Characterization of posttranslational modifications of human A33 antigen, a novel palmitoylated surface glycoprotein of human gastrointestinal epithelium

Ritter, G; Cohen, LS; Nice, EC; Catimel, B; Burgess, AW; Moritz, RL; Ji, H; Heath, JK; White, SJ; Welt, S; Old, LJ; Simpson, RJ

Author(s): Ritter, G; Cohen, LS; Nice, EC; Catimel, B; Burgess, AW; Moritz, RL; Ji, H; Heath, JK; White, SJ; Welt, S; Old, LJ; Simpson, RJ;
Details: Publication Year 1997-07-30,Volume 236,Issue #3,Page 682-686
Journal Title: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Publication Type: Journal Article
Abstract: Monoclonal antibody (mAb) A33 recognizes a differentiation antigen (A33) expressed in normal human gastrointestinal epithelium and in 95% of human colon cancers. Murine mAb A33 shows specific targeting of colon cancer in humans and a humanized A33 antibody is currently being evaluated in the clinic. The cDNA far the human A33 antigen has recently been cloned, and sequence comparison indicated that the A33 antigen is a novel human cell surface molecule of the immunoglobulin superfamily. Because mAb A33 recognizes a conformational epitope, only a partial characterization of the A33 antigen has been carried out to date. In this report we show that the A33 antigen is (I) N-glycosylated, containing approximately 8 K of N-linked carbohydrate and there is no evidence for O-glycosylation, sialylation or glycophosphatidylinositol, and (ii) S-acylated in vitro, incorporating [H-3] palmitic acid linked through a hydroxylamine-sensitive thioester bond. The S-palmitoylation may be involved in regulating the internalization process initiated by binding of mAb A33 to cell surface A33 antigen. (C) 1997 Academic Press.
Publisher: ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS
Keywords: COLON-CANCER; RECEPTOR; IDENTIFICATION; PROTEINS
Publisher's Version: https://doi.org/10.1006/bbrc.1997.6966
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 1997-07-30 12:00:00