The uncatalyzed rates of enolization of dihydroxyacetone phoshate and of glyceraldehyde 3-phosphate in neutral aqueous solution. The quantitative assessment of the effectiveness of an enzyme catalyst.
By a combination of methods involving enzyme-catalyzed reactions and classical iodination techniques it has been possible to obtain all the relevant rate constants for the uncatalyzed interconversion of dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate via their common enediol intermediate. These rate constants are compared with those for the individual steps of the triosephosphate isomerase catalyzed reaction, and a quantitative picture of the effectiveness of the enzyme as a catalyst has been delineated. It is apparent that the enzyme increases the enolization rate of dihydroxyacetone phosphate by a factor of more than 10(9) over that of the uncatalyzed reaction.
D002238:Carbohydrate Epimerases / Q000378:metabolism*; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D004099:Dihydroxyacetone Phosphate / Q000378:metabolism; D005985:Glyceraldehyde / Q000031:analogs & derivatives* / Q000378:metabolism; D007536:Isomerism; D007700:Kinetics; D009943:Organophosphorus Compounds / Q000378:metabolism; D014305:Triose-Phosphate Isomerase / Q000378:metabolism*; D014306:Trioses
D009943:Organophosphorus Compounds; D014306:Trioses; D005985:Glyceraldehyde; D004099:Dihydroxyacetone Phosphate; D002238:Carbohydrate Epimerases; D014305:Triose-Phosphate Isomerase