Molecular target size of an l-glutamate receptor from the cockroach central nervous system

Abstract

l-Glutamate binding to cockroach central nervous system (CNS) membranes is unaffected by freeze-drying and subsequent rehydration. The dissociation constant is similarly unaltered by irradiation at a dose of 3 Mrad which affects only the number of biologically active binding sites. A molecular weight estimate for this insect CNS l-glutamate receptor was performed using irradiation inactivation analysis. By this method a molecular target size of approximately 77.8 kDa was determined. This figure is in agreement with the molecular weight found by other authors for l-glutamate binding sites in the rat brain.