电鳐电器官膜上的高特异性、低亲和力TCP结合部位

A HIGH SPECIFICITY LOW AFFINITY TCP BINDING SITE ON THE CELL MEMBRANE OF Torpedo ELECTRIC ORGAN

本研究对电鳐电器官中的膜受体与神经性毒剂和重活化剂间的作用进行了探讨。发现在电鳐电器官中有一个高特异性、低亲和力的 2 -噻吩基 -哌啶基 -1,1-环己烷 ( TCP)结合位点 ,这个结合位点具有可饱和性。 TCP和苯环利啶 ( PCP)为同类物 ,它们作用于 TCP/ PCP同一位点。 [3H] TCP结合的 Bmax=1.16pmol/ mg protein,KD=16.13nmol/ L。有机磷毒剂能竞争性地抑制标记化合物 [3H] TCP与 TCP结合位点的结合 ,终浓度 10 - 3mol/ L的 Vx,梭曼 ,沙林及塔崩分别可产生 81% ,48% ,41%及38%的抑制。而膦酰化乙酰胆碱脂酶的四种重活化剂 HI-6、LuH6 、2 -PAM及 TMB4也对 [3H] TCP与 TCP受体的结合产生5 3%、48%、30 %及 30

In this paper, interactions between the membrane receptor of Torpedo electric organ and the organophosphorous poisons or reactivators were studied. A high specificity low affinity 2-thienyl-piperidyl-1,1-cyclohexane (TCP) saturable binding site was found at the cell membrane of Torpedo electric organ. TCP is an analog of PCP acting on a single TCP/PCP binding site. Binding of TCP showed a Bmax of 1.16 pmol/mg protein and a K D of 16.13 nmol/L. Organophosphorous poisons competitively inhibited the binding of TCP with the binding site. At final concentration of 1 mmol/L, Vx, soman,sarin and tabun caused 81%, 48%, 41% and 38% of inhibition, and the phosphonylated-acetylcholinesterase reactivators HI-6, LH 6, 2-PAM and TMB 4 caused 53%, 48%, 30% and 30% of inhibition.