Composition, stability and electrolyte permeability of Golgi membranes from lactating-rat mammary gland.
1. Golgi membrane vesicles, isolated from lactating-rat mammary gland and greatly enriched in galactosyltransferase (EC 2.4.1.22), contained over 40 separate bands of protein, including some periodic acid)(Schiff-staining material and free thiol groups, when analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 2. The membrane lipids were enriched in phosphatidylcholine, phosphatidylethanolamine and unesterified cholesterol. 3. Membrane fluidity, as monitored by the fluorescence polarization of 1,6-diphenylhexa-1,3,5-triene, increased linearly over 5-37 degrees C. 4. The vesicle membranes were impermeable to lactose over a wide pH range, but admitted electrolytes of molecular weight below about 300. 5. These properties are discussed with respect to other cellular membranes and the secretion of milk products.
D000818:Animals; D002463:Cell Membrane Permeability; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006056:Golgi Apparatus / Q000032:analysis / Q000378:metabolism*; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000032:analysis / Q000378:metabolism; D007774:Lactation; D007785:Lactose / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D011247:Pregnancy; D051381:Rats; D012492:Salts / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000032:analysis
D008563:Membrane Lipids; D008565:Membrane Proteins; D012492:Salts; D013438:Sulfhydryl Compounds; D007785:Lactose