Cation-stimulated ATPase activity in purified plasma membranes from tobacco hornworm midgut.
Cation-stimulated ATPase activity in purified plasma membranes from tobacco hornworm midgut.
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烟草天蛾中肠纯化质膜中阳离子刺激的 ATP 酶活性。
DOI:
10.1016/0005-2736(86)90356-1
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发表时间:
1986
期刊:
影响因子:
--
通讯作者:
Harvey,WR
中科院分区:
文献类型:
--
作者:
Wieczorek,H;Wolfersberger,MG;Cioffi,M;Harvey,WR
Purified goblet cell apical membranes fromManduca sextalarval midgut exhibit a specific ATPase activity approx. 20-fold higher than that in the 100 000 ×gpellet of a midgut homogenate. The already substantial ATPase activity in this plasma membrane segment is doubled in the presence of 20–50 mM KCl. At ATP concentrations ranging from 0.1 to 3.0 mM, the presence of 20 mM KCl leads to a 10-fold increase in the enzyme's affinity for ATP. ATPase activity is greatest at a pH of approx. 8. In addition to ATP, GTP serves as a substrate, but CTP, ADP, AMP andp-nitrophenyl phosphate do not. Either Mg2+or Mn2+is required for activity and cannot be replaced by Ca2+or Zn2+. The ATPase activity of goblet cell apical membranes is inhibited by neither the typical (Na++ K+)-ATPase inhibitors, ouabain and orthovanadate, nor by the typical mitochondrial F1F0-ATPase inhibitors, azide and oligomycin. Although 1.5 μM DCCD is ineffective, 150 μM DCCD leads to total inhibition of ATPase activity. The ATPase activity of goblet cell apical membranes is stimulated not only by K+, but also, in order of decreasing effectiveness, by Rb+, Li+, Na+and even Mg2+. Replacement of Cl−by Br−, F−and HCO3−has less influence than variation of the cations. However, replacement of Cl−by NO3−inhibits strongly this ATPase activity. The ATPase activity described above is characteristic of the alkali metal ion pump containing apical membranes of goblet cells and is not enhanced to a similar degree in other purified midgut epithelial cell plasma membrane segments. Its localization, its broad cation specificity and its insensitivity to ouabain all mimic properties of active ion transport by the lepidopteran midgut and suggest this ATPase as a possible key component of the lepidopteran electrogenic alkali metal ion pump.
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DOI:
--
发表时间:
1982
期刊:
The Journal of biological chemistry
影响因子:
--
作者:
Gluck,S;Kelly,S;Al-Awqati,Q
通讯作者:
Al-Awqati,Q
影响因子:
4.8
作者:
M. Gustin;D. Goodman
通讯作者:
D. Goodman
影响因子:
3.5
作者:
L. Lichko;L. Okorokov
通讯作者:
L. Okorokov
DOI:
10.1016/0020-1790(84)90090-8
发表时间:
1984
期刊:
Insect Biochemistry
影响因子:
--
作者:
L. Deaton
通讯作者:
L. Deaton
影响因子:
2.9
作者:
R. Adolfsen;E. Moudrianakis
通讯作者:
E. Moudrianakis