Purification and characterization of the class-II D-fructose 1,6-bisphosphate aldolase from Escherichia coli (Crookes' strain)

Abstract

A new form of the class II D fructose 1,6 bisphosphate aldolase (EC 4.1.2.13) of E. coli (Crookes' strain) was isolated from an extract of glycerol bacteria. It has a higher molecular weight (approx. 80000) than previous preparations of the enzyme and closely resembles the typical class II aldolase from yeast in size and amino acid composition. On the other hand, its kinetic behaviour is not typical of a class II aldolase. The enzyme has no requirement for thiol compounds either for stability or activity, added K+ ions have no effect, and the optimum pH for the cleavage activity is unusually high. The class II enzymes from the prokaryote E. coli and the eukaryote yeast show no immunological identity. However, the similarity of their structures suggests that they have evolved from a common ancestor.