Non-equivalent cooperation between the two nucleotide-binding folds of P-glycoprotein.
Non-equivalent cooperation between the two nucleotide-binding folds of P-glycoprotein.
复制标题
P-糖蛋白的两个核苷酸结合折叠之间的非等价合作。
DOI：
10.1016/s0005-2736(98)00099-6
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
K. Ueda
中科院分区：
文献类型：
--
作者：
Y. Takada;K. Yamada;Y. Taguchi;K. Kino;M. Matsuo;S. Tucker;T. Komano;T. Amachi;K. Ueda
为了确定两个核苷酸结合折叠（NBFs）在人p -糖蛋白（一种多药物转运体）功能中的作用，我们在NBFs的Walker a （WA）基序（核心共识序列）中将关键赖氨酸残基突变为蛋氨酸，将关键半胱氨酸残基突变为丙氨酸。我们研究了这些突变对n -乙基马来酰亚胺（NEM）和ATP结合的影响，以及对钒酸盐诱导的8-叠氮-[α-32P]ATP捕获的影响。在两种NBFs中，WAlysine或NEM结合半胱氨酸的突变阻断了钒酸盐诱导的p -糖蛋白的核苷酸捕获。这些结果表明，如果一个NBF是非功能性的，即使另一个功能性的NBF含有结合的核苷酸，也不会发生ATP水解，进一步表明p -糖蛋白的两个NBF之间存在很强的协同作用。然而，我们发现在一个NBF上的NEM修饰对另一个NBF上ATP结合的影响是不相等的，这表明两个NBF在p -糖蛋白功能中的作用是不相等的。
To identify the roles of the two nucleotide-binding folds (NBFs) in the function of human P-glycoprotein, a multidrug transporter, we mutated the key lysine residues to methionines and the cysteine residues to alanines in the Walker A (WA) motifs (the core consensus sequence) in the NBFs. We examined the effects of these mutations on N-ethylmaleimide (NEM) and ATP binding, as well as on the vanadate-induced nucleotide trapping with 8-azido-[α-32P]ATP. Mutation of the WAlysine or NEM binding cysteine in either of the NBFs blocked vanadate-induced nucleotide trapping of P-glycoprotein. These results suggest that if one NBF is non-functional, there is no ATP hydrolysis even if the other functional NBF contains a bound nucleotide, further indicating the strong cooperation between the two NBFs of P-glycoprotein. However, we found that the effect of NEM modification at one NBF on ATP binding at the other NBF was not equivalent, suggesting a non-equivalency of the role of the two NBFs in P-glycoprotein function.
DOI：
10.1073/pnas.91.11.4698
发表时间：
1994-05-24
影响因子：
11.1
作者：
HWANG, TC;NAGEL, G;GADSBY, DC
通讯作者：
GADSBY, DC