Tunnicliff G, Youngs T L
Indiana University School of Medicine, Evansville 47712.
Proc Soc Exp Biol Med. 1989 Oct;192(1):11-5. doi: 10.3181/00379727-192-42947.
The nucleotide ATP was shown to be a reversible inhibitor of partially purified gamma-aminobutyrate aminotransferase isolated from mouse brain. This inhibition was of the competitive type with respect to the substrate, gamma-aminobutyric acid (Ki = 3.7 +/- 0.6 mM), but was noncompetitive with respect to both the second substrate alpha-ketoglutarate and the cofactor pyridoxal 5'-phosphate. Two analogues of ATP, ADP and GTP, also gave rise to an inhibition gamma-aminobutyrate aminotransferase that was similar to that produced by ATP. These results are consistent with the view that mouse brain gamma-aminobutyric acid aminotransferase could be under regulatory control by ATP and certain other nucleotides within the mitochondria.
已证明核苷酸ATP是从小鼠脑中分离出的部分纯化的γ-氨基丁酸转氨酶的可逆抑制剂。这种抑制作用相对于底物γ-氨基丁酸而言属于竞争性类型（Ki = 3.7 +/- 0.6 mM），但相对于第二种底物α-酮戊二酸和辅因子磷酸吡哆醛5'-磷酸而言是非竞争性的。ATP的两种类似物ADP和GTP也会对γ-氨基丁酸转氨酶产生抑制作用，其抑制作用与ATP产生的抑制作用相似。这些结果与以下观点一致，即小鼠脑γ-氨基丁酸转氨酶可能受到线粒体内ATP和某些其他核苷酸的调节控制。
