Tsim K W, Cheng C H
Mol Cell Endocrinol. 1984 Nov;38(1):61-6. doi: 10.1016/0303-7207(84)90145-x.
Incorporation of p-chloromercuribenzene sulphonate (PCMBS) (1mM) in the assay medium for rat hepatic lactogenic receptor produced complete inhibition of binding of [125I]oPRL to the membrane. However, the presence of the thiol-reactive agent produced no effect on the binding of [125I]bGH to rat hepatic somatogenic receptor. Pretreatment of rat hepatic membrane with PCMBS inhibited the binding of [125I]oPRL but not that of [125I]bGH. The lactogenic receptor binding inhibition by PCMBS pretreatment was both concentration- and time-dependent, with complete inhibition at 0.5 mM for 60 min at 0 degrees C. Scatchard analysis of [125I]oPRL binding to membrane at 50% inhibition by PCMBS (0.11 mM) revealed that the binding capacity was decreased rather than the binding affinity. Furthermore, the inhibition of lactogenic receptor binding by PCMBS could be reversed by dithioerythritol (DTE) treatment. Following 80% inhibition by 0.2 mM PCMBS, full recovery of receptor binding was achieved at 6 mM DTE for 60 min at 0 degrees C. The 'recovered' membrane showed no difference from the control membrane in terms of binding capacity and affinity.
在用于大鼠肝脏催乳素受体的测定培养基中加入对氯汞苯磺酸盐（PCMBS）（1mM）可完全抑制[125I]oPRL与膜的结合。然而，这种硫醇反应性试剂的存在对[125I]bGH与大鼠肝脏生长激素受体的结合没有影响。用PCMBS预处理大鼠肝膜可抑制[125I]oPRL的结合，但不抑制[125I]bGH的结合。PCMBS预处理对催乳素受体结合的抑制作用具有浓度和时间依赖性，在0℃下0.5mM处理60分钟可完全抑制。对在PCMBS（0.11mM）抑制50%时[125I]oPRL与膜的结合进行Scatchard分析表明，结合能力降低而非结合亲和力降低。此外，PCMBS对催乳素受体结合的抑制作用可通过二硫苏糖醇（DTE）处理逆转。在0.2mM PCMBS抑制80%后，在0℃下6mM DTE处理60分钟可使受体结合完全恢复。“恢复”的膜在结合能力和亲和力方面与对照膜没有差异。
