TY - JOUR
T1 - G 6 PD Long Prairie
T2 - a new glucose 6 phosphate dehydrogenase mutant exhibiting normal sensitivity to inhibition by NADPH and accompanied by nonspherocytic hemolytic anemia
AU - Johnson, G. J.
AU - Kaplan, M. E.
AU - Beutler, E.
PY - 1977
Y1 - 1977
N2 - The enzymatic properties of a new glucose 6 phosphate dehydrogenase (G 6 PD) variant (G 6 PD Long Prairie) were studied in a white patient with chronic nonspherocytic hemolysis. The red cells were found to have 2.3%-7.7% normal enzymatic activity. The mutant enzyme exhibited marked heat instability, an increased pH optimum, a moderately decreased Km for G 6 P, and increased utilization of 2 deoxyglucose 6 phosphate and deamino NADP. The Km for NADP and Ki for NADPH were both normal. G 6 PD Long Prairie is an interesting new G 6 PD variant that demonstrates that chronic hemolysis can be associated with modestly decreased G 6 PD activity despite normal sensitivity to inhibition by NADPH. Although increased sensitivity to inhibition by NADPH has been postulated to decrease intracellular enzyme activity, resulting in enhanced susceptibility to hemolysis in certain G 6 PD variants with only moderately decreased enzymatic activity, an alternative mechanism of hemolysis, possibly enzyme thermolability, exists in G 6 PD Long Prairie.
AB - The enzymatic properties of a new glucose 6 phosphate dehydrogenase (G 6 PD) variant (G 6 PD Long Prairie) were studied in a white patient with chronic nonspherocytic hemolysis. The red cells were found to have 2.3%-7.7% normal enzymatic activity. The mutant enzyme exhibited marked heat instability, an increased pH optimum, a moderately decreased Km for G 6 P, and increased utilization of 2 deoxyglucose 6 phosphate and deamino NADP. The Km for NADP and Ki for NADPH were both normal. G 6 PD Long Prairie is an interesting new G 6 PD variant that demonstrates that chronic hemolysis can be associated with modestly decreased G 6 PD activity despite normal sensitivity to inhibition by NADPH. Although increased sensitivity to inhibition by NADPH has been postulated to decrease intracellular enzyme activity, resulting in enhanced susceptibility to hemolysis in certain G 6 PD variants with only moderately decreased enzymatic activity, an alternative mechanism of hemolysis, possibly enzyme thermolability, exists in G 6 PD Long Prairie.
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U2 - 10.1182/blood.v49.2.247.247
DO - 10.1182/blood.v49.2.247.247
M3 - Article
C2 - 12846
AN - SCOPUS:0017327857
SN - 0006-4971
VL - 49
SP - 247
EP - 251
JO - Blood
JF - Blood
IS - 2
ER -