PURIFICATION AND PROPERTIES OF FRUCTOSE DIPHOSPHATE ALDOLASE FROM FUSARIUM OXYSPORUMF. LYCOPERSICI

Abstract

Fructose-1,6-diphosphate (FDP) aldolase obtained from crude extracts of the mycelium of Fusarium lycopersici was purified approximately 35-fold. The properties of the enzyme indicate that it resembles the FDP aldolase commonly found in yeast and bacteria rather than that found in animals or plants. The inhibitory action of p-hydroxymercuribenzoate, N-ethylmaleimide, and iodosobenzoate suggests that a sulfhydryl group may be involved in an active site. The inhibitions caused by methylene blue in the presence of light and of diazosulfanilic acid suggest that histidine and (or) tyrosine residues may also be involved in the active site. The importance of this site has been established by demonstrating that fructose diphosphate and D-glyceraldehyde-3-phosphate prevent inactivation by diazosulfanilic acid whereas dihydroxyacetone phosphate is without effect.