山莨若碱通过膜脂影响兔肾(Na~++K~+)-ATP酶的构象及活性

研究了山莨菪碱对处于不同脂双层的兔肾外髓质(Na~++K~+)-ATP酶活性的影响,结果表明山莨菪碱对(Na~++K~+)-ATP酶的抑制作用与该酶所处的脂环境密切相关,如对去脂后的酶活性无明显影响,而对重组于酸性磷脂脂质体的酶比对重组于中性磷脂脂质体的酶有更大的抑制作用。园二色性实验表明,山莨菪碱使带349个界面脂分子的(Na~++K~+)-ATP酶二级结构发生明显变化,而对带189个界面脂分子的酶无明显作用。另外利用差示量热扫描研究表明山莨菪碱对酸性磷脂和中性磷脂脂质体或脂酶体相变行为有不同的影响。

EFFECT OF ANISODAMINE ON CONFORMATION AND ACTIVITY OF RABBIT KIDNEY(Na~(+) + K~(+)) - ATPase THROUGH INTERACTING WITH MEMRBANE

(Na++ K+)-ATPase purified from rabbit kidney outer medulla was incorporated into various phospholipid liposomes. Effect of anisodamine on the activity of reconstituted (Na++ K+ ) - ATPase has been studied. Results showed that the inhibition of anisodamine on the activities of (Na+ + K+) - ATPase are related closely to the phospholipids. No significant effect was observed on the activity of delipided (Na++ K+) - ATPase. Moreover the inhibition of anisodamine on the activity of (Na++ K + ) - ATPase reconstituted into acid phospholipid liposomes is stronger than that in neutral phospholipid liposomes. The CD experiments showed that anisodamine can change the secondary structure of (Na++K + ) - ATPase with 349 annular phospholipids, but cann't change that of (Na+ + K+) - ATPase with 189 annular phospholipids. Different effects of anisodamine on the phase behavior of acid and neutral phospholipid liposomes have been studied with DSC.