FRUCTOSE 1,6 - DIPHOSPHATE UTILIZAT10N AND SOME PROPERTIES OF PYRUVATE KINASE FROM THE MUSCLE OF CONCHOLEPAS CONCHOLEPAS

Abstract

The fructose 1-6 diphosphate consumption in slices homogenized and supematants (23.000 xg and 105.000 xg) of muscle of Concholepas concholepas is studied. The final producís ofglycolisis are phosphoglycerol and pyruvate. The fluoride inhibits thc appearance of Pyruvatc and does not modify thc fructose diphosphate consumption and the phosphoglycerol production. The arsenate stimulate fructose diphosphate consumption and increases the production of phosphoglycerol and pyruvate. When thc arsenate and fluoride are simultaneously present, the inhibitory action of fluoride increase. The enzyme Pyruvate kinase (ATP Pyruvate phosphotransferase, E.C. 2.7.1.40) separated from Concholepas concholepas muscle, shows homotropic cooperativity towards the substrate phosphoenol pyruvate with an optimal pH between 7,2 and 7,7. The enzime is markedly inhibited by L phenyl alanine with modification of the valué of K0 5 and n (H ttl number) from 0,12 mM with and 1,64 to 0,4 mM and 2,6 respectivcly. The fructose diphosphate has an activating effect on the enzyme and abolish the inhibitory effect of the Phenylalanine.