Incorporation of Pure Hydrolases Isolated from Brush Border Membranes in Single-Bilayer Lecithin Vesicles

摘要: 1. Both hydrolases, sucrase-isomaltase and aminopeptidase, when in their integral form interact with lecithin to stable lipoprotein complexes. 2. In the reconstituted complex hydrophobic part of amphipathic hydrolase is incorporated bilayer. The total protein mass contact less than 5%. 3. With bilayer belongs isomaltase subunit. 4. The such that bulk not lipid surface but sitting on a stalk minimum length ~ 10 A. 5. The lipoprotein/membrane system single-bilayer vesicle (diameter 300 A) all enzyme being oriented towards external aqueous phase. 6. Lecithin forms single closed surrounding waterfilled cavity. properties — molecular packing, segmental cooperative motion, ion permeability are unchanged compared reference state pure vesicle. 7. No hydrolysis-related sugar transfer measured recon-stituted membrane system. 8. The following resemble those observed “native” brush border membranes: (1) asymmetric incorporation enzyme; (2) attachment accomplished by “anchor”, which subunit; (3) susceptibility membrane-bound hydrolases detachment papain treatment: proteins released from either indistinguishable sedimentation behavior electrophoretic mobility polyacrylamide gels.