Immunochemical study of beta-glucuronidase inhibitor from porcine sublingual gland. Relationship between the antigenic determinant and the active site of the inhibitor.

Following removal of sialic acid by neuraminidase treatment the activity of the beta-glucuronidase inhibitor was remarkably decreased, but the antigenic determinant was not affected. A partial common antigen to the inhibitor was isolated from porcine small intestine, by successive fractionation of trypsin extraction of the latter on Sephadex G-150, DEAE-cellulose and Sepharose 4B column chromatography. The immunologic and characteristic properties of the common antigen were compared with those of the beta-glucuronidase inhibitor is not identical with its antigenic determinant.