Overview:
RET or ret proto-oncogene is a member of the cadherin superfamily that encodes one of the receptor tyrosine kinases, which are cell-surface molecules that transduce signals for cell growth and differentiation. RET can undergo oncogenic activation in vivo and in vitro by cytogenetic rearrangement (1). Mutations in the RET gene are associated with the disorders multiple endocrine neoplasia, type IIA, multiple endocrine neoplasia, type IIB, Hirschsprung disease, and medullary thyroid carcinoma. RET signaling pathway, by regulating the development of both the nervous and lymphoid system in the gut, plays a key role in the molecular mechanisms that orchestrate intestine organogenesis (2).
Gene Aliases:
PTC, RET51, CDHF12, CDHR16, RET-ELE1, MTC1, HSCR1, MEN2A, MEN2B
Genbank Number:
NM_020630
References:
1.Grieco, M. et.al: PTC is a novel rearranged form of the ret proto-oncogene and is frequently detected in vivo in human thyroid papillary carcinomas. Cell 60: 557-563, 1990.2.Veiga-Fernandes, H. et.al: Tyrosine kinase receptors RET is a key regulator of Peyer's patch organogenesis. Nature 446: 547-551, 2007.
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1.对于抑制剂筛选工作（求ic50）是不是体系内酶与底物的量（底物应该是过量的）对实验结果影响不大。
2.如果要求算Km值，是不是需要知道反应产物的绝对量。反应时间文献上都是5分钟，反应速度就用反应产物量除以反应时间即可。
3.酶是进口分装的，规格5U，一次用不完，用PBS稀释后如何保存
谢谢
1、测定酶比活力：底物需要过量么？测定时间多长？是否可以加入过量的底物，然后测定3min吸光度的增加值，从吸光度的变化值计算比活力。
2、在酶抑制剂筛选的过程中，是否需要保证底物过量？还是要水浴一定时间让反应完全？我看到文献说用终浓度为0.1μmol/mL的底物，终浓度为45U/ml的酶，我想问，假设总体积为1ml，那么终浓度为45U/ml的酶岂不是每分钟能转化4.8μmol的底物？那么0.1μmol/mL的底物不就几秒钟就反应完了？那么怎么测定初速度？
《血管紧张素转换酶抑制剂在心血管病中应用的中国专家共识》.PDF(242.69k)
2、可逆抑制剂：包括
a、竞争性抑制剂，抑制剂与底物竞争性结合酶反应中心，使Km增大，而Vmax不变 b、非竞争性抑制剂，酶与抑制剂结合后还能与底物结合，但活性降低，使Vmax减小，而Km不变
c、反竞争性抑制剂，酶只能与底物结合后才能与抑制剂结合，Vmax与Km都减小
可逆抑制剂可用透析等方法除去，使酶恢复作用
