| Autor: |
Takikawa, Shin-Ichiro, Curtius, Hans-Christoph, Redweik, Udo, Leimbacher, Walter, Ghisla, Sandro |
| Předmět: |
|
| Zdroj: |
European Journal of Biochemistry; 12/1/86, Vol. 161 Issue 2, p295-302, 8p |
| Abstrakt: |
6-Pyruvoyl-tetrahydropterin synthase, which catalyzes the first step in th conversion of 7,8-dihydroneopterin triphosphate to tetrahydrobiopterin, was purified approximately 140,000-fold to apparent homogeneity from human liver. The molecular mass of the enzyme is estimated to be 83 kDa. 7,8-Dihydroneopterin triphosphate was a substrate of the enzyme in the presence of Mg2+, and the pH optimum of the reaction was 7.5 in Tris HCl buffer. The Km value for 7,8-dihydroneopterin triphosphate was 10 µM. The product of this enzymatic reaction was the presumed intermediate 6-puruvoyl-tetrahydropterin. This latter compound was converted to tetrahydrobiopterin in the presence of NADPH and partially purified sepiapterin reductase from human liver. The conditions and the effect of N-acetylserotonin on this reaction, and on the formation of the intermediates 6-(1'-hydroxy-2'-oxopropyl)-tetrahydropterin and 6-(1' oxo-2'-hydroxypropyl)-tetrahydropterin have been studied. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
