Reversible change in light scattering following formation of ADP-sensitive phosphoenzyme in Na+,K+-ATPase modified with N-[p-(2-benzimidazolyl)phenyl]maleimide.
Reversible change in light scattering following formation of ADP-sensitive phosphoenzyme in Na+,K+-ATPase modified with N-[p-(2-benzimidazolyl)phenyl]maleimide.
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在用 N-[对-(2-苯并咪唑基)苯基]马来酰亚胺修饰的 Na,K-ATP 酶中形成 ADP 敏感磷酸酶后，光散射发生可逆变化。
DOI：
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发表时间：
1986
影响因子：
4.8
通讯作者：
S. Iida
中科院分区：
文献类型：
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作者：
K. Taniguchi;K. Suzuki;T. Sasaki;H. Shimokobe;S. Iida
当用N-[p-（2-苯并咪唑基）苯基]马来酰亚胺修饰的猪肾Na+，K+-ATP酶制剂在2 M Na+和Mg 2+存在下被ATP磷酸化形成ADP敏感性磷酸酶（E1 P）时，观察到光散射增加（3.5 +/- 0.2%），其具有负荧光强度（-1.5 +/- 0.3%）。添加K+或哇巴因E1 P减少光散射的情况下观察到的ATP的原始水平。停流测量表明，伴随E1 P形成的荧光变化（t1/2 = 0.1 s）发生在光散射变化（t1/2 = 1 s）之前。寡霉素对散射增加率影响不大，但能减弱K+对E1 P的影响，使光散射减弱，荧光增强。向K+敏感性磷酸酶（E2 P）中加入2 M Na+立即降低荧光（t1/2 = 0.02 s）以形成E1 P，随后光散射缓慢增加（t1/2 = 0.25 s）。寡霉素降低上述变化的速率，伴随着E2 P向E1 P的转变。这些数据表明，在ATP水解过程中，E1 P的种类先于E2 P的形成顺序出现。
An increase in light scattering (3.5 +/- 0.2%) was observed when pig kidney Na+,K+-ATPase preparations modified with N-[p-(2-benzimidazolyl)phenyl] maleimide were phosphorylated by ATP in the presence of 2 M Na+ with Mg2+ to form ADP-sensitive phosphoenzyme (E1P), which had a negative fluorescence intensity (-1.5 +/- 0.3%). Addition of K+ or ouabain to E1P reduced the light scattering to the original level observed in the absence of ATP. Stopped flow measurements showed that the fluorescence change accompanying the E1P formation (t1/2 = 0.1 s) occurred preceding the light-scattering change (t1/2 = 1 s). Oligomycin affected the rate of the scattering increase little, but it diminished the effect of K+ on E1P to reduce the light scattering and increase the fluorescence. The addition of 2 M Na+ to K+-sensitive phosphoenzyme (E2P) immediately decreased the fluorescence (t1/2 = 0.02 s) to form E1P which was followed by a slow increase in the light scattering (t1/2 = 0.25 s). Oligomycin reduced both rates of the above changes accompanying the transition of E2P to E1P. The data suggest the sequential appearance of species of E1P that precede E2P formation during the hydrolysis of ATP.