Stereospecific d-Glucokinase of Aerobacter aerogenes

Glucokinase from Entamoeba histolytica and Related Organisms*

“…Its glucose Km is two orders of magnitude smaller than that reported byWalker (1963) for liver glucokinase. Unlike the glucokinase of Aerobacter aerogenes reported byKamel et al (1966) the amebal enzyme does not require the glucose configuration at carbon 2 and its inhibition by ADP is an order of magnitude greater than that of this bacterial enzyme. Unlike the glucokinase from Brevibac-…”

“…Of particular interest are the low apparent inhibition constants of AMP and ADP found for the amebal glucokinase. Product inhibition by ADP had been noted for glucokinases or hexokinases by Asensio (1960), Kamel et al (1966), Saito (1965, Salas et al (1965), Grossbard and Schimke (1966), and Seed and Baquero (1965), but only the first three investigations reported strictly competitive kinetics vs. ATP. In the case of the amebal enzyme the inhibition by ADP was competitive and greater than that reported for the other enzymes.…”

Glucokinase of Dictyostelium discoideum

“…The glucokinase of D. discoideum is unable to catalyze the phosphorylation of mannose, fructose, or 2-deoxyglucose, nor is the phosphorylation of glucose inhibited by these sugars. In these properties the enzyme resembles the glucokinase from Aerobacter aerogenes (Kamel et al, 1966) and differs from the multiple substrate hexokinases of yeast and mammals (Crane, 1962). The slime mold appears to have only one enzyme able to phosphorylate glucose at the terminal (C-6) carbon.…”