active and allosteric sites

[briteyellowness]

the description says:

in one patient with recurrent gout, excreted uric acid levels were found to be three times normal levels. the patient's red blood cells exhibited markedly increased levels of 5-PRPP. Assays revealed that the patient had normal levels of PRPP synthase, but the enzyme activity was three times normal levels in cultured cells. The pH optimum and enzyme activity of the purified enzyme were normal.

how do i know that the increased levels of uric acid is a mutation that affects the allosteric site of PRPP synthetase and not the active site?

[sdekivit]

if there was an enhancement in the active site, the mutation must be in the gene for the enzyme. Since the enzyme is just normal (when purified the effect is normal), the effect must be allosteric.

When the active site of the enzyme is affected, the purified enzyme would also have an increased activity.

[briteyellowness]

what does it mean when the enzyme was purified?

[mith]

separated from the mix.