I'm specifically interested in the reaction as it occurs in EMIT assays. Does H+ stay in solution, hence the need for precise buffering, or is it released as gas?
Hi there,
The oligomerization state of an enzyme has absolutely no effect on the equation of the chemical reaction (which can actually occur in absence of enzyme). So 2 protons are produced per molecule of G6P, they are used to reduce the NADP+ into NADPH+H+which is the cofactor for the reaction. But no release of free H+ which is solvated into H3O+ (leading to the acidification of the aqueous phase).
Hydrogen in gaseous form is diatomic (H2). H+ is also called the proton. In water, it is hydrated to H3O+, as Dominique Liger said. The concentration of H+ (or H3O+) is what is being measured when one measures the pH of a solution.
Buffering is required for enzyme reactions because the activity of enzymes depend on the pH of the medium. They usually exhibit an optimal pH.
this link is useful
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3325335/
regards
Enzyme multiplied immunoassay technique EMIT is a homogenous competitive immunoassay where the antigen is labeled with glucose 6-phosphate dehydrogenase as Dominque liger said the protons are produced per molecule of G6P, they are used to reduce the NADP+ into NADPH+H+which is the cofactor for the reaction. But no release of free H+ which is solvated into H3O+ leading to the acidification of the aqueous phase .Good luck
The enzyme acts at optimum pH and the activity does not change at pH equal to buffers pKa+1 and pKa-1. In the reaction catalysed catalysed by Glucose -6- phosphate dehydrogenase the NADP is coenzyme and reduced to NADPH +H. There is no as such release of hydrogen ions .
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