Half-of-the sites reactivity in the catalytic mechanism of yeast glyceraldehyde 3-phosphate dehydrogenase.

摘要: Abstract A half-of-the-sites effect is observed in yeast glyceraldehyde 3-phosphate dehydrogenase for the substrate phosphoglyceroyl phosphate, i.e. only two of four initially identical subunits are acylated. Excess accelerates hydrolysis enzyme both presence and absence NAD. This acceleration by excess acyl phosphate not seen with acetyl or furyl acryloyl even though a both. Both triacetyl trifuryl enzymes can be prepared from nitrophenyl esters first group accelerated these derivatives. Apparently all three cases, ligand-induced changes cause rate acylation diacyl to decreased deacylation triacyl increased. The balance rates true leads which absent pseudo-substrates. Thus, co-operativity between has an important on catalytic mechanism.