Low-affinity Na+ sites on (Na+ +K+)-ATPase modulate inhibition of Na+-ATPase activity by vanadate.
Low-affinity Na+ sites on (Na+ +K+)-ATPase modulate inhibition of Na+-ATPase activity by vanadate.
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(Na K )-ATPase 上的低亲和力 Na 位点调节钒酸盐对 Na -ATPase 活性的抑制。
DOI：
10.1016/0005-2736(82)90560-0
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
P. Hudgins
中科院分区：
文献类型：
--
作者：
G. H. Bond;P. Hudgins
Na+-ATP酶活性在低Na+浓度下对钒酸盐的抑制极其敏感，其中Na+仅占据高亲和力活化位点。Na+占据低亲和力激活位点，以逆转钒酸盐对Na+-ATP酶和（Na+，K+）-ATP酶活性的抑制。Na+的这种作用相对于钒酸盐和Mg 2+是竞争性的。酶对钒酸盐的表观亲和力被K+显着增加。K+的主要作用可能是将Na+从其激活Na+-ATP酶活性的低亲和力位点置换。
Na+-ATPase activity is extremely sensitive to inhibition by vanadate at low Na+concentrations where Na+occupies only high-affinity activation sites. Na+occupies low-affinity activation sites to reverse inhibition of Na+-ATPase and (Na+, K+)-ATPase activities by vanadate. This effect of Na+is competitive with respect to both vanadate and Mg2+. The apparent affinity of the enzyme for vanadate is markedly increased by K+. The principal effect of K+may be to displace Na+from the low-affinity sites at which it activates Na+-ATPase activity.