The occurrence of a trypsin inhibitor in brain

Abstract
The tryptic hydrolysis of benzoyl-DL-argininyl-[beta]-naphthylamide is inhibited by homogenates of human and ox brain. The inhibitor is associated primarily with the membranous portion of the particulate matter, and is not found in the 90,000 g supernatant fraction. The reaction of the inhibitor with trypsin is rapid. The inhibitor is heat-stable.