Ishikawa T
Department of Biochemistry, Osaka University Medical School, Japan.
FEBS Lett. 1989 Mar 27;246(1-2):177-80. doi: 10.1016/0014-5793(89)80278-9.
Sarcolemmal vesicles prepared from rat heart exhibited ATP-dependent uptake of S-(2,4-dinitrophenyl)glutathione (DNP-SG), which obeyed Michaelis-Menten kinetics with an apparent Km of 21 microM for DNP-SG and a Vmax of 0.27 nmol.10 min-1.mg protein-1. Several model glutathione S-conjugates inhibited DNP-SG uptake, but leukotriene C4 inhibited uptake much more significantly even at lower concentrations (competitive inhibition, Ki = 1.5 microM). However, leukotrienes D4 and E4, which lack the gamma-glutamyl moiety, were less effective. The results suggest that the ATP-dependent transport system has a high affinity for leukotriene C4, and may be responsible for the translocation of this compound.
从大鼠心脏制备的肌膜囊泡表现出对S-(2,4-二硝基苯基)谷胱甘肽(DNP-SG)的ATP依赖性摄取，其遵循米氏动力学，对DNP-SG的表观Km为21μM，Vmax为0.27 nmol·10 min-1·mg蛋白-1。几种谷胱甘肽S-缀合物模型抑制DNP-SG摄取，但白三烯C4即使在较低浓度下也能更显著地抑制摄取(竞争性抑制，Ki = 1.5μM)。然而，缺乏γ-谷氨酰部分的白三烯D4和E4效果较差。结果表明，ATP依赖性转运系统对白三烯C4具有高亲和力，可能负责该化合物的转运。
