Searching for enzyme using NAD(P)H and ADP ---> NAD(P)+ and ATP

pgegen at rnaworld.bio.ukans.edu pgegen at rnaworld.bio.ukans.edu
Tue Jan 16 13:48:24 EST 1996


In <tyr-2-1301961731540001 at duckter.glaxo.med.ualberta.ca>, tyr-2 at bones.biochem.ualberta.ca (Karl Fischer) writes:
>  I am searching
>> for a *single* enzyme which catalyzes a reaction ultimately converting
>> ADP to ATP (presumably using NAD(P)H.
>
>David,
>
>According to the volume of Stryer's Biochemistry I have before me,
>nucleoside diphosphokinase is able to transfer the phosphoryl group from
>GTP to ADP to yield GDP and ATP.
>
>Hope this helped.
>
>Karl the hepB guy
>
>-- 
>Karl Fischer
>tyr-2 at bones.biochem.ualberta.ca

??? I'm not sure that a SINGLE enzyme can do this -- phosphotransferase enzymes typically are not also oxidoreductases. The CLASSICAL example of precisely what you want to do is to use two sequential steps of glycolysis, namely the two-enzyme system of GAPDH+PGK, which together convert GA3P + Pi + ADP + NAD(P)H <==> 3-PGA + ATP + NAD(P)+.  The two enzymes are glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase, and the reactants are glyceraldehyde-3-phosphate (GA3P) and 3-phosphoglycerate 
(3PGA). GAPDH catalyzes substrate-level phosphorylation of GA3P + Pi + NAD(P)H <==> 1,3-BPG (1,3-bisphosphoglycerate) + NAD(P)+, and PGK converts 1,3-BPG + ADP ==> 3-PGA + ATP. 
GAPDH from animal cytoplasm is (usually) strictly NADH-dependent, whereas chloroplast GAPDH is strictly dependent upon NADPH. 

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