aprtase การใช้

• When APRTase has reduced or nonexistent activity, adenine accumulates from other pathways.
• Since then, two categories of APRTase deficiency have been defined in humans.
• APRTase proceeds via a bi bi ordered sequential mechanism, involving the formation of a ternary complex.
• Most research on APRTase reports that Mg 2 + is essential for phosphoribosyl transfer, and this is conserved across Type I PRTases.
• In human APRTase, it is thought that adenine's N9 proton is abstracted by Glu104 to form an oxacarbenium transition state.
• Type II deficiency causes APRTase to have a reduced affinity for PRPP, resulting in a tenfold increase in the K M value.
• Although APRTase is functionally redundant in these organisms, it becomes more important during periods of rapid growth, such as embryogenesis and tumor growth.
• A diagnosis of APRTase deficiency can be made by analyzing kidney stones, measuring DHA concentrations in urine, or analyzing APRTase activity in erythrocytes.
• A diagnosis of APRTase deficiency can be made by analyzing kidney stones, measuring DHA concentrations in urine, or analyzing APRTase activity in erythrocytes.
• Since the consequences of APRTase deficiency in humans is comparatively mild and treatable, it may be possible to treat certain parasitic infections by targeting APRTase function.
• Since the consequences of APRTase deficiency in humans is comparatively mild and treatable, it may be possible to treat certain parasitic infections by targeting APRTase function.
• However, a recent effort to resolve the structure of human APRTase was unable to locate a single site for Mg 2 +, but did find evidence to suggest a Cl  " atom near Trp98.
• This functions as the nucleophile to attack the anomeric carbon of PRPP, forming AMP and displacing pyrophosphate from PRPP . The mechanism of APRTase is generally consistent with that of other PRTases, which conserve the function of displacing PRPP's ?-1-pyrophosphate using a nitrogen nucleophile, in either an S N 1 or S N 2 attack.