THE CONVERSION OF PHENYLALANINE TO TYROSINE

我们成功地结晶了大鼠肝脏苯丙氨酸羟基酶。我们 已经发现这种酶的目标大小是粗品中的一个单体 萃取物，但在纯化的酶中是二聚体。天然辅因子， 四氢生物蝶呤，似乎只能够抑制 酶的四聚体形式。一种酶，它参与 四氢生物蝶呤、4A-甲醇脱水酶的再生途径 已经通过制备抗体和随后的 组织特异性研究。这种酶最近被认为是这样的 实验室以及其他，将与一种新形式的 高苯丙氨酸血症。7-四氢生物蝶呤，一种新的异构体 天然辅因子，在某些特定环境中发现的相对高浓度的辅因子 高苯丙氨酸血症患者，是一种部分解偶联的辅因子 苯丙氨酸羟基酶。部分解偶联氧化 进一步研究了苯丙氨酸羟基酶催化的四氢蝶呤类化合物 显示出遵循与完全非耦合的 反应。

We have successfully crystallized rat liver phenylalanine hydroxylase. We have found that the target size of this enzyme is a monomer in the crude extract, but a dimer in the purified enzyme. The natural cofactor, tetrahydrobiopterin, appears to be capable of inhibiting only the tetrameric form of the enzyme. An enzyme that is involved in the regeneration pathway of tetrahydrobiopterin, 4A-carbinolamine dehydratase, has been further studied by the preparation of an antibody and a subsequent tissue specificity study. This enzyme has recently been suggested by this laboratory, as well as others, to be linked to a new form of hyperphenylalaninemia. 7-tetrahydrobiopterin, a novel isomer of the natural cofactor that is found in relatively high concentrations in certain hyperphenylalaninemic patients, is a partially uncoupled cofactor for phenylalanine hydroxylase. The partially uncoupled oxidation of tetrahydropterins by phenylalanine hydroxylase was further studied and shown to follow a similar mechanism to that for the fully uncoupled reaction.