An immunochemical study of monkey ( Macaca mulatta) brain cortex grey matter soluble proteins

Abstract

Grey matter dissected from perfused Rhesus monkey brain cortex was extracted for soluble proteins (MTB) by a mild procedure involving homogenization of grey matter with 5 m M sodium phosphate buffer, pH 7·2, and high speed centrifugation at 80, 730 g. Antibodies to MTB were raised in albino rabbits by injecting an emulsion of MTB complexed with methylated bovine serum albumin and Freund's complete adjuvant. A minimum of nine antigens were shared by monkey serum, liver, lungs, spleen and kidneys. Using anti-MTB antiserum absorbed successively with monkey serum and organ soluble proteins, five of the nine antigens were shown to be monkey brain specific by immunoelectrophoresis. These antigens have mobilities of serum α and β globulins. No difference with regard to the regional (occipital, sensory and motor cortex) distribution of the specific antigens was noticed in monkey brain cortex. The specific antigens were distributed in four relatively basic fractions on DEAE cellulose columns and separated by stepwise elution with sodium phosphate buffer-NaCl mixture of increasing salt concentration and reducing pH. The DEAE fraction were shown to be heterogenous by analytical ultracentrifugation, immunoelectrophoresis and disc electrophoresis methods.