title: Vitamin B12-binding proteins in human gastric mucosa. General pattern and demonstration of intrinsic factor isoproteins typical of mucosa.
abstract: Extracts of human stomach mucosa were shown to contain immunoreactive intrinsic factor and small amounts of R protein and transcobalamin II. In gel filtration the mucosal vitamin B12-intrinsic factor complex behaved as though its molecular weight were smaller than the corresponding complex in gastric juice. In isoelectric focusing both the gastric juice and mucosal vitamin B12-intrinsic factor complexes resolved into numerous isoproteins. These findings were verified by DEAE-cellulose chromatography. The mucosal intrinsic factor isoprotein pattern contained, in addition to the isoproteins found in gastric juice, components with higher isoelectric points -- that is, pH 5.73-6.64.
mesh_terms: D001798:Blood Proteins; D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D005750:Gastric Juice / Q000032:analysis; D005753:Gastric Mucosa / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007437:Intrinsic Factor / Q000032:analysis*; D007525:Isoelectric Focusing; D011506:Proteins / Q000032:analysis*; D014155:Transcobalamins / Q000032:analysis; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D001798:Blood Proteins; D011506:Proteins; D014155:Transcobalamins; D007437:Intrinsic Factor; D014805:Vitamin B 12