A New Class of Conformationally Rigid Analogues of 4-Amino-5-halopentanoic Acids, Potent Inactivators of γ-Aminobutyric Acid Aminotransferase
作者:Jian Qiu、Richard B. Silverman
DOI:10.1021/jm9904755
日期:2000.2.1
Inactivation leads to covalent attachment of 2 equiv of inactivator after gel filtration; upon urea denaturation, 1 equiv of radioactivity remains bound to the enzyme. This suggests that, unlike the open-chain anlogue, the conformationally rigid analogue becomes, at least partially, attached to an active-site residue. It appears that the conformational constraint has a larger effect on inactivators that
最近,我们发现(Qiu,J .; Pingsterhaus,JM; Silverman,RBJ Med。Chem。1999,42,4725-4728),GABA氨基转移酶(GABA-AT)灭活剂vigabatrin的构象刚性类似物不是GABA-灭活剂。在。为了确定这是否是GABA-AT灭活剂的普遍现象,合成了其他GABA-AT灭活剂的几种单和二卤素取代的构象刚性类似物(7-15),即4-氨基-5-卤代戊酸。潜在的GABA-AT灭活剂。其中四个(+)-7,(-)-9,(+)-10和(+)-15是灭活剂,尽管不如相应的开链类似物有效。氟和溴取代的类似物的最大失活速率常数k(inact)是可比的,表明CX键的断裂不是决定速率的。与该观察结果一致的发现是,[3-(2)H] -10对3.3的失活表现出氘同位素效应,这表明CH键的裂解是决定速率的步骤。氟化类似物7灭活GABA-AT的速率是相应的开链类