Congenital sucrase-isomaltase deficiency arising from cleavage and secretion of a mutant form of the enzyme
J. Clin. Invest. Ralf Jacob, et al. 106:281 doi:10.1172/JCI9677 [Go to this article.]

Figure 2
Molecular forms of SI in CSID and in normal control. Biopsy samples from a patient with CSID and a normal control were biosynthetically labeled for the indicated times with ³⁵S-methionine. (a) The specimens were homogenized, solubilized, and immunoprecipitated with monoclonal anti-SI antibodies. The immunoprecipitates were divided into two equal parts; one part was treated with Endo H and the other was not treated. Finally the samples were subjected to SDS-PAGE on 6% slab gels. Gels were analyzed by fluorography. (b) Direct comparison of Endo H–treated immunoprecipitates from the patient with CSID and the control shown in a. The additional band appearing in the CSID samples in a and b is indicated by an arrowhead. (c) The detergent extracts of the biopsy samples from the patient and the control were also immunoprecipitated with mAb’s directed against LPH and aminopeptidase N (ApN), which served as control brush border glycoproteins. The immunoprecipitates were analyzed on SDS-PAGE on 6% slab gels.