Glycolysis in retinal extracts

Abstract

An aqueous extract of ox retina was prepared which on addition of adenosinetriphosphate (ATP) or adenylic acid (AA) produced lactic acid (LA) from its precursors. The amt. formed from glucose was increased by phosphate (P) and MgCl2, that from glycogen was increased by P, but not by MgCl2, and that from hexosediphosphate conversely. A dialysed ext. acting on glucose, required both and also ATP; its action on glycogen required P; hexosediphosphate required only MgCl2. AA could replace ATP as coenzyme, but the amt. of LA formed from glucose was smaller unless P was also added. Cozy-mase could not take the place of ATP or AA as coenzyme. Glycolysis of all 3 substrates was inhibited by addition of iodoacetic acid, NaF or glyceraldehyde. Carbohydrate-phosphoric esters apparently were not formed. When AA was used as coenzyme P was transferred to an easily hydro-lysed ester, probably ATP. Hexosediphosphate produced a large increase in P and some difficultly hydrolysable ester; in fluoride-poisoned extract glucose produced some of this ester but when pyruvate was added a much larger amount, approx. equivalent to the amt. of LA formed and to the decreased P.