title: Macroamylasemia: variable response of a 7S and a 11S macroamylase to phosphate-benzoic acid buffer during gel filtration.
abstract: During thin layer or macrocolumn gel filtration with Sephadex G 200, a 7S macroamylase dissociated completely to normal-sized amylase when the eluant was phosphate-benzoic acid buffer. In contrast a 11S macroamylase was not affected by the buffer and amylase activity was associated with 11S proteins. Since phosphate-benzoic acid buffer is used in a thin layer screening method described by Peeters et al. (9), some macroamylases may go undetected. After treatment of the 7S macroamylase with phosphate-benzoic acid buffer, the amylase-free 7S proteins obtained formed macroamylase with added pancreatic amylase. This indicates that the buffer did not inhibit the activity of the macroamylase, but caused a dissociation of the macroamylase during gel filtration. The difference in the effect of phosphate-benzoic acid buffer on the two types of macroamylases may be attributed to the difference in affinity of binding proteins for the amylase molecule.
mesh_terms: D000681:Amylases / Q000097:blood* / Q000494:pharmacology / Q000652:urine; D001565:Benzoates / Q000494:pharmacology; D002021:Buffers; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel / Q000379:methods; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D008832:Microchemistry; D008875:Middle Aged; D010195:Pancreatitis / Q000097:blood / Q000201:enzymology; D010710:Phosphates / Q000494:pharmacology
chemical_list: D001565:Benzoates; D002021:Buffers; D046911:Macromolecular Substances; D010710:Phosphates; D000681:Amylases; C001663:macroamylase