Purification and properties of the phosphate eliminating enzyme involved in the biosynthesis of BH4 in man.
An enzyme catalyzing the elimination of triphosphate from 7,8-dihydroneopterin triphosphate in the presence of Mg2+ has been purified approx. 3000 fold from human liver. It has a molecular weight of approx. 63'000, a pI value of 4.4 - 4.6 and is stable at 80 degrees C for 5 min. This enzyme catalyzes the formation of tetrahydrobiopterin in the presence of sepiapterin reductase, Mg2+ and NADPH. It is thus possible, that it also catalyzes the internal oxidoreduction leading to formation of the intermediate 6-pyruvoyl-tetrahydropterin, suggesting that no further enzyme is obligatory for biosynthesis of tetrahydrobiopterin.
Heintel
D
D
Leimbacher
W
W
Redweik
U
U
Zagalak
B
B
Curtius
H C
HC
D001708:Biopterins / Q000031:analogs & derivatives / Q000096:biosynthesis*; D006801:Humans; D007526:Isoelectric Point; D008099:Liver / Q000032:analysis*; D008274:Magnesium / Q000378:metabolism; D008970:Molecular Weight; D009249:NADP / Q000378:metabolism; D019798:Neopterin / Q000031:analogs & derivatives; D011621:Pteridines / Q000096:biosynthesis* / Q000378:metabolism; D011755:Pyrophosphatases / Q000302:isolation & purification* / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
D011621:Pteridines; C013490:dihydroneopterin triphosphate; D001708:Biopterins; D009249:NADP; D019798:Neopterin; D011755:Pyrophosphatases; C023129:dihydroneopterin triphosphate pyrophosphohydrolase; C003402:sapropterin; D008274:Magnesium