MOLECULAR BIOLOGY OF THE PTERIN-DEPENDENT HYDROLASES AND ANCILLARY ENZYMES

苯丙氨酸的高水平表达（占总蛋白的25%） 缺少前七个氨基酸残基的羟化酶序列 在E.杆菌 这个克隆体的野生型 正在建设中，以便比较催化性能 和定向诱变。 部分人苯丙氨酸羟化酶cDNA克隆已被 特征和全长克隆正在追求通过 优化cDNA文库的合成。 在老鼠身上进行的扩大实验中， 在大鼠中诱导糖尿病已经结合 与胰岛素治疗，以明确定义的机制，增加 苯丙氨酸羟化酶活性和mRNA水平的变化。 人二氢蝶啶还原酶的全长编码序列 已经在细菌载体上表达，并且酶分离自 大规模培养物已被表征。 二氢蝶啶还原酶克隆已被用作探针， 确定该基因在4号染色体上的位置， 亨廷顿氏病基因座。

High level (25% of total protein) expression of a phenylalanine hydroxylase sequence lacking the first seven amino acid residues has been achieved in E. coli. A wild type version of this clone is under construction to allow comparisons of catalytic properties and directed mutagenesis. Partial human phenylalanine hydroxylase cDNA clones have been characterized and full length clones are being pursued through the synthesis of optimized cDNA libraries. Expanded experiments with rats have been conducted where chemical induction of diabetes in rats has been performed in conjunction with insulin treatment to clearly define the mechanism of increased phenylalanine hydroxylase activity and mRNA in diabetic rats. A full length coding sequence for human dihydropteridine reductase has been expressed on a bacterial vector and enzyme isolated from large scale cultures has been characterized. The dihydropteridine reductase clone has been used as a probe to identify the location of this gene on chromosome 4 near the Huntington's Disease locus.