Evidence of enrichment in glycine receptors of crude synaptic membranes from rat spinal cord following Triton X-100 treatment

Abstract

Treatment of synaptic membranes from rat brainstem and spinal cord with the nonionic detergent Triton X-100 at 1–10 μl/mg protein caused a marked increase in glycine receptor ( 3H)strychnine binding expressed per mg of residual membrane protein. The effect was maximal (220±6% of control) at 5 μl Triton/mg protein, while higher concentrations caused progressive loss of strychnine binding ability of membranes (27±6% at 25 μl Triton/mg protein). The increase in strychnine binding caused by low Triton X-100 reflected an increase in membrane B max, the k D being unaffected by the treatment. The affinity of glycine analogues for receptor sites was not appreciably affected by the detergent either. The findings suggest an enrichment of the synaptic membrane preparation in glycine receptors, caused by the solubilization by Triton of membrane constituents not related to the receptor sites.