Ahmad S, Daniel E E
Department of Biomedical Sciences, McMaster University Health Science Centre, Hamilton, Canada.
Biochem Biophys Res Commun. 1989 Nov 30;165(1):422-8. doi: 10.1016/0006-291x(89)91087-5.
We have studied the effect of sulfhydryl agents on the binding of 125I-tyr3-neurotensin to the purified plasma membranes from circular smooth muscle and on the in vitro response of circular muscle strips of canine small intestine to neurotensin. Dithiothreitol (DTT) enhanced the binding by about 80%. Cysteine (a reductant) also enhanced the binding while cystine (an oxidant) reduced the binding to the similar extent. DTT stimulated the tissue in the organ bath and abolished the stimulatory response to low concentrations of neurotensin. The stimulatory response to acetylcholine was not altered by DTT. The implications of the role of disulfide bridges in the neurotensin response is discussed.
我们研究了巯基试剂对125I-酪氨酰3-神经降压素与环形平滑肌纯化质膜结合的影响，以及对犬小肠环形肌条对神经降压素的体外反应的影响。二硫苏糖醇（DTT）使结合增强了约80%。半胱氨酸（一种还原剂）也增强了结合，而胱氨酸（一种氧化剂）则使结合降低了相似程度。DTT在器官浴中刺激组织，并消除了对低浓度神经降压素的刺激反应。DTT未改变对乙酰胆碱的刺激反应。讨论了二硫键在神经降压素反应中的作用的意义。
