title: Metal-replacement studies in Bacillus stearothermophilus aldolase and a comparison of the mechanisms of class I and class II aldolases.
abstract: A comparison of the product-inhibition patterns during cleavage of D-fructose 1,6-diphosphate by aldolases from yeast, rabbit muscle and Bacillus stearothermophilus shows an ordered reaction sequence for all three enzymes, with dihydroxyacetone phosphate the last-leaving product. Addition of Zn2+, Co2+, Fe2+, Mn2+ or Cd2+ ions to the inactive apo-(Bacillus stearothermophilus aldolase) restores activity to different extents, whereas Ni2+, Mg2+ or Cu2+ ions have no effect. The cleavage activity of this aldolase is not enhanced by added K+ ion. The effects of metal replacement on thermal stability, Km and Vmax. are given and the possible role of the metal is discussed in the light of these results.
mesh_terms: D000818:Animals; D001051:Apoenzymes; D002104:Cadmium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D008345:Manganese / Q000494:pharmacology; D009132:Muscles / Q000201:enzymology; D011817:Rabbits; D013696:Temperature; D015003:Yeasts / Q000201:enzymology; D015032:Zinc / Q000494:pharmacology
chemical_list: D001051:Apoenzymes; D002413:Cations, Divalent; D002104:Cadmium; D003035:Cobalt; D008345:Manganese; D005634:Fructose-Bisphosphate Aldolase; D015032:Zinc