5ukw
From Proteopedia
Crystal structure of human Glucose 6-phosphate Dehydrogenase mutant (A277C) complexed with G6P
Structural highlights
Disease[G6PD_HUMAN] Defects in G6PD are the cause of chronic non-spherocytic hemolytic anemia (CNSHA) [MIM:305900]. Deficiency of G6PD is associated with hemolytic anemia in two different situations. First, in areas in which malaria has been endemic, G6PD-deficiency alleles have reached high frequencies (1% to 50%) and deficient individuals, though essentially asymptomatic in the steady state, have a high risk of acute hemolytic attacks. Secondly, sporadic cases of G6PD deficiency occur at a very low frequencies, and they usually present a more severe phenotype. Several types of CNSHA are recognized. Class-I variants are associated with severe NSHA; class-II have an activity <10% of normal; class-III have an activity of 10% to 60% of normal; class-IV have near normal activity.[1] Function[G6PD_HUMAN] Produces pentose sugars for nucleic acid synthesis and main producer of NADPH reducing power. Publication Abstract from PubMedGlucose-6-phosphate dehydrogenase (G6PDH) catalyzes the oxidation of glucose-6-phoshate to 6-phospho-gluconolactone with the concomitant reduction of NADP+ to NADPH. In solution, the recombinant human G6PDH is known to be active as dimers and tetramers. To distinguish between the kinetic properties of dimers and tetramers of the G6PDH is not trivial. Steady-state kinetic experiments are often performed at low enzyme concentrations, which favor the dimeric state. The present work describes two novel human G6PDH mutants, one that creates four disulfide bonds among apposing dimers, resulting in a 'cross-linked' tetramer, and another that prevents the dimer to dimer association. The functional and structural characterizations of such mutants indicate the tetramer as the most active form of human G6PDH. Mutations in the tetramer interface of human glucose-6-phosphate dehydrogenase reveals kinetic differences between oligomeric states.,Ranzani AT, Cordeiro AT FEBS Lett. 2017 Mar 30. doi: 10.1002/1873-3468.12638. PMID:28370139[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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