Pore properties of the Golgi membrane from lactating-rat mammary gland. Effects of pH and temperature and reconstitution into phospholipid vesicles.
Golgi-membrane vesicle penetration was studied by osmotic lysis. Pronounced temperature dependence of mannitol and mannoheptitol penetration over 0-37 degrees C gave linear Arrhenius plots, with activation energies of 75 and 117 kJ/mol respectively. Glucose penetration was constant over pH 5-9, but was respectively faster and slower at higher and lower pH values. Solubilized, dialysed, heat-stable extracts of Golgi membrane were reconstituted into egg yolk phospholipid membranes with apparent recovery of specific permeability. Penetration is interpreted in terms of a pore, for which the Renkin equation predicts a radius of about 0.54 nm.
D000818:Animals; D002463:Cell Membrane Permeability; D005260:Female; D005947:Glucose / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D007774:Lactation; D007785:Lactose / Q000378:metabolism; D008081:Liposomes; D008321:Mammary Glands, Animal / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000502:physiology; D009996:Osmotic Fragility; D010743:Phospholipids / Q000378:metabolism; D018272:Porins; D011247:Pregnancy; D051381:Rats; D013696:Temperature
D008081:Liposomes; D008565:Membrane Proteins; D010743:Phospholipids; D018272:Porins; D005947:Glucose; D007785:Lactose