Human milk bile-salt-stimulated lipase is extremely reactive with the monoclonal antibody 1CF11 which recognizes a human-specific carbohydrate antigen

1CF11 is a monoclonal antibody obtained after being raised in a mouse by in jection of human milli MUC1 mucin as the antigen. Its reactivity was found to be unique ill that it only reacts with a carbohydrate epitope shared by glycoproteins in human secretions, while its chemical nature is still unkno wn. Since a glycloprotein of Mr 135,000 (135K) in human milli was found to react extremely strongly with this antibody, me intended in this study to i solate the glycoprotein by: a combination of various chromatographic techni ques and identify it. It is a human milk bile-salt-stimulated lipase. By co mparison of its immunoreactivity and glycan structures so far reported with those of lactoferrin from human milk it is suggested that tile epitope rec ognized by mAb 1CFI1 could be a human-specific novel glycan.