Walters J R, Howard A, Charpin M V, Gniecko K C, Brodin P, Thulin E, Forsén S
Gastroenterology Unit, United Medical School, London, U.K.
Biochem Biophys Res Commun. 1990 Jul 31;170(2):603-8. doi: 10.1016/0006-291x(90)92134-l.
Calcium transport by the Ca2(+)-pumping ATPase in rat duodenal basolateral-enriched membrane vesicles was stimulated by synthetic calbindin-D9k in a similar fashion to the purified natural protein. In order to elucidate the mechanism of this effect, various synthetic mutant proteins were studied. Proteins with modifications to the N-terminal Ca2(+)-binding domain, or to a cluster of negatively-charged surface residues had altered Ca2(+)-binding but these changes did not affect the stimulation of vesicular Ca2+ transport. It appears that these domains are not essential for the interaction between calbindin-D9k and the intestinal basolateral Ca2(+)-pump.
大鼠十二指肠富含基底外侧膜囊泡中Ca2(+)-泵ATP酶的钙转运，受到合成钙结合蛋白-D9k的刺激，其方式与纯化的天然蛋白相似。为了阐明这种效应的机制，研究了各种合成突变蛋白。对N端Ca2(+)-结合结构域或一组带负电荷的表面残基进行修饰的蛋白，其Ca2(+)-结合发生了改变，但这些变化并不影响囊泡Ca2+转运的刺激作用。看来这些结构域对于钙结合蛋白-D9k与肠道基底外侧Ca2(+)-泵之间的相互作用并非必不可少。
