Martínez-Farnos L, Gubert S, Bozal J
Rev Esp Fisiol. 1978 Sep;34(3):295-300.
Structural requirements of substrates and inhibitors of guinea-pig brain guanine aminohydrolase (GAH; E.C. 3.5.4.3), have been established by working with guanine analogs (8-azaguanine, 1-methylguanine, thioguanine and guanosine), purine precursors (5-aminoimidazole-4-carboxamide), purinic bases (xanthine, hypoxanthine, adenine and uric acid) and pyrimidinic bases (citosine, thymine and uracil). The need of the purine ring for the compounds to behave as substrate has been shown. The carbonyl group placed in position 6, plays an essential role in purine and pyrimidine binding to the enzymatic molecule. 5-aminoimidazole-4-carboxamide and allopurinol are enzyme inhibitors, while guanosine, thioguanine and 2,6-diaminopurine are not. Groups in positions 2, 6, 7 and 9 play a significant role in the union of the guanine molecule with guanine aminohydrolase.
通过使用鸟嘌呤类似物（8-氮杂鸟嘌呤、1-甲基鸟嘌呤、硫代鸟嘌呤和鸟苷）、嘌呤前体（5-氨基咪唑-4-甲酰胺）、嘌呤碱（黄嘌呤、次黄嘌呤、腺嘌呤和尿酸）以及嘧啶碱（胞嘧啶、胸腺嘧啶和尿嘧啶），已确定豚鼠脑鸟嘌呤氨基水解酶（GAH；E.C. 3.5.4.3）底物和抑制剂的结构要求。已表明化合物作为底物需要嘌呤环。位于6位的羰基在嘌呤和嘧啶与酶分子的结合中起重要作用。5-氨基咪唑-4-甲酰胺和别嘌呤醇是酶抑制剂，而鸟苷、硫代鸟嘌呤和2,6-二氨基嘌呤不是。2、6、7和9位的基团在鸟嘌呤分子与鸟嘌呤氨基水解酶的结合中起重要作用。
