Kainic acid binding in human caudate nucleus: effect of Huntington's disease

Kainic acid binding was measured in crude membrane fractions prepared from postmortem human caudate tissue of control persons and patients afflicted with Huntington's disease. A significant reduction in binding sites with no change in affinity was found in the Huntington's tissue, the apparent dissociation constants (Kd) and maximal binding (Bmax) values were: 6.4 nM/119 fmol/mg protein (control) and 5.9 nM/53 fmol/mg protein (Huntington). The kainic acid binding showed a remarkable specificity for L-glutamate.