Mechanism of glyceraldehyde-3-phosphate transfer from aldolase to glyceraldehyde-3-phosphate dehydrogenase.
The catalytic interaction of glyceraldehyde-3-phosphate dehydrogenase with glyceraldehyde 3-phosphate has been examined by transient-state kinetic methods. The results confirm previous reports that the apparent Km for oxidative phosphorylation of glyceraldehyde 3-phosphate decreases at least 50-fold when the substrate is generated in a coupled reaction system through the action of aldolase on fructose 1,6-bisphosphate, but lend no support to the proposal that glyceraldehyde 3-phosphate is directly transferred between the two enzymes without prior release to the reaction medium. A theoretical analysis is presented which shows that the kinetic behaviour of the coupled two-enzyme system is compatible in all respects tested with a free-diffusion mechanism for the transfer of glyceraldehyde 3-phosphate from the producing enzyme to the consuming one.
Kvassman
J
J
Avdelningen för Biokemi, Kemicentrum, Lunds Universitet, Sweden.
Pettersson
G
G
Ryde-Pettersson
U
U
D000818:Animals; D004163:Diphosphoglyceric Acids / Q000096:biosynthesis; D004735:Energy Transfer; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D005635:Fructosediphosphates / Q000378:metabolism; D005985:Glyceraldehyde / Q000031:analogs & derivatives*; D005986:Glyceraldehyde 3-Phosphate / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D009132:Muscles / Q000201:enzymology; D009243:NAD / Q000096:biosynthesis; D010085:Oxidative Phosphorylation; D011817:Rabbits
D004163:Diphosphoglyceric Acids; D005635:Fructosediphosphates; D009243:NAD; D005986:Glyceraldehyde 3-Phosphate; C015891:glycerate 1,3-biphosphate; D005985:Glyceraldehyde; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005634:Fructose-Bisphosphate Aldolase; C029063:fructose-1,6-diphosphate