SOLUBILIZATION OF [S-35] LANTHIONINE KETIMINE BINDING-SITES FROM BOVINE BRAIN

Lanthionine ketimine (LK) binding sites were solubilized from bovine b rain membranes using 3-[(3-cholamidopropyl)dimethylammonio]-1 (CHAPS) and Triton X-100. 10 mM CHAPS in 0.5 M potassium phosphate, pH 7.0, co ntaining 20% glycerol was selected to solubilize LK binding entities. Some properties of CHAPS-solubilized LK binding sites have been studie d. The CHAPS-solubilized preparation appeared to contain a homogenous population of binding sites for [(35)]LK. Binding properties indicated that the solubilized binding sites were similar to the membrane-bound sites. [S-35]LK specific binding was inhibited by other structurally related ketimines obtaining a similar rank order of inhibition for the soluble and the membrane-bound preparations. The successful solubiliz ation of [S-35]LK binding sites is a useful starting point for the pur ification of this binding protein.