title: The insertion of pig microvillus aminopeptidase into the membrane as probed by [125I]iodonaphthylazide.
abstract: The insertion of pig intestinal microvillus aminopeptidase (EC 3.4.11.2) into the membrane was studied by the hydrophobic photolabel [125I]iodonaphthylazide. The aminopeptidase was either labelled in the microvillus membrane and purified, or labelled after detergent solubilization and purification in a buffer containing Triton X-100, and then isolated from the reaction mixture. Of the three subunits A (Mr 162000), B (Mr 123000) and C (Mr 62000) of the aminopeptidase, A and B, but not C contained radioactivity, indicating that both subunit A and B carry anchoring peptide. The radioactivity when released from the subunits by trypsin treatment was connected to low-molecular-weight material.
mesh_terms: D000626:Aminopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001386:Azides; D002462:Cell Membrane / Q000201:enzymology*; D007421:Intestine, Small / Q000201:enzymology*; D046911:Macromolecular Substances; D008871:Microvilli / Q000201:enzymology*; D008970:Molecular Weight; D009281:Naphthalenes; D013552:Swine
chemical_list: D001386:Azides; D046911:Macromolecular Substances; D009281:Naphthalenes; C015298:iodonaphthylazide; D000626:Aminopeptidases