M. Kunitz isolated crystalline inorganic pyrophosphatase from yeast and characterized its catalytic activity in a 1952 study. The purified protein accelerated hydrolysis of pyrophosphate to separate phosphate units. By testing a purified preparation, the experiment could connect a reaction to a particular enzyme rather than merely observing that an unfractionated biological extract changed its reaction substrate.[ref]
Crystalline inorganic pyrophosphatase isolated from baker's yeast by M. Kunitz. abstract, isolation and catalytic specificity
A revealing result was the requirement for activating metal ions, including magnesium. The reaction rate also depended on pH, temperature and the amounts of enzyme and reaction substrate. Related organic phosphate compounds were not equivalent substrates for this preparation. Thus a shared chemical linkage does not guarantee recognition by the same enzyme. As a simple assay illustration, complete cleavage of 10 micromolar pyrophosphate produces 20 micromolar additional phosphate units. Measuring that increase requires subtracting any phosphate already present; measuring an initial reaction rate further requires a time interval before substantial substrate depletion.[ref]
Crystalline inorganic pyrophosphatase isolated from baker's yeast by M. Kunitz. abstract, activating ions, rate dependence and tested organic compounds
Articles by others on the same topic
There are currently no matching articles.