Phase separation of rat intestinal brush border membrane proteins using Triton X-114.
Rat intestinal microvillus membrane contains at least 24 polypeptides, of which 18 can be solubilized using Triton X-114 at 4 degrees C. Upon phase separation at 32 degrees C, 11 proteins separated nearly completely into the detergent-rich phase, while 9 proteins were found exclusively in the aqueous phase. Enzymes which were uniquely included in the detergent phase were alkaline phosphatase, leucine aminopeptidase, gamma-glutamyl transpeptidase, and Ca2+-Mg2+ ATPase. The proteins which were excluded from the detergent phase and found exclusively in the aqueous phase included the disaccharidases (glucoamylase, sucrase-isomaltase, trehalase, lactase) and the ileal receptor for the intrinsic factor-cobalamin complex. Integral membrane proteins can thus be separated during solubilization into two groups prior to further purification or characterization.
D000818:Animals; D004186:Disaccharidases / Q000302:isolation & purification; D007422:Intestines / Q000032:analysis*; D008565:Membrane Proteins / Q000302:isolation & purification*; D008871:Microvilli / Q000032:analysis; D008970:Molecular Weight; D017830:Octoxynol; D011092:Polyethylene Glycols; D051381:Rats; D011956:Receptors, Cell Surface / Q000302:isolation & purification; D012995:Solubility
D008565:Membrane Proteins; D011956:Receptors, Cell Surface; C029486:intrinsic factor-cobalamin receptor; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D004186:Disaccharidases