Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1992 Jun;99(2):553–560. doi: 10.1104/pp.99.2.553

K+ Stimulation of ATPase Activity Associated with the Chloroplast Inner Envelope 1

Weihua Wu 1,2, Gerald A Berkowitz 1
PMCID: PMC1080499  PMID: 16668922

Abstract

Studies were conducted to characterize ATPase activity associated with purified chloroplast inner envelope preparations from spinach (Spinacea oleracea L.) plants. Comparison of free Mg2+ and Mg·ATP complex effects on ATPase activity revealed that any Mg2+ stimulation of activity was likely a function of the use of the Mg·ATP complex as a substrate by the enzyme; free Mg2+ may be inhibitory. In contrast, a marked (one- to twofold) stimulation of ATPase activity was noted in the presence of K+. This stimulation had a pH optimum of approximately pH 8.0, the same pH optimum found for enzyme activity in the absence of K+. K+ stimulation of enzyme activity did not follow simple Michaelis-Menton kinetics. Rather, K+ effects were consistent with a negative cooperativity-type binding of the cation to the enzyme, with the Km increasing at increasing substrate. Of the total ATPase activity associated with the chloroplast inner envelope, the K+-stimulated component was most sensitive to the inhibitors oligomycin and vanadate. It was concluded that K+ effects on this chloroplast envelope ATPase were similar to this cation's effects on other transport ATPases (such as the plasmalemma H+-ATPase). Such ATPases are thought to be indirectly involved in active K+ uptake, which can be facilitated by ATPase-dependent generation of an electrical driving force. Thus, K+ effects on the chloroplast enzyme in vitro were found to be consistent with the hypothesized role of this envelope ATPase in facilitating active cation transport in vivo.

Full text

PDF
553

Images in this article

556Figure 3
on p.556

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Balke N. E., Hodges T. K. Plasma membrane adenosine triphosphatase of oat roots: activation and inhibition by mg and ATP. Plant Physiol. 1975 Jan;55(1):83–86. doi: 10.1104/pp.55.1.83. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Baysdorfer C., Bassham J. A. Spinach pyruvate kinase isoforms : partial purification and regulatory properties. Plant Physiol. 1984 Feb;74(2):374–379. doi: 10.1104/pp.74.2.374. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Briskin D. P., Poole R. J. Characterization of a k-stimulated adenosine triphosphatase associated with the plasma membrane of red beet. Plant Physiol. 1983 Feb;71(2):350–355. doi: 10.1104/pp.71.2.350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chang T., Penefsky H. S. Aurovertin, a fluorescent probe of conformational change in beef heart mitochondrial adenosine triphosphatase. J Biol Chem. 1973 Apr 25;248(8):2746–2754. [PubMed] [Google Scholar]
  5. Demmig B., Gimmler H. Properties of the Isolated Intact Chloroplast at Cytoplasmic K Concentrations : I. Light-Induced Cation Uptake into Intact Chloroplasts is Driven by an Electrical Potential Difference. Plant Physiol. 1983 Sep;73(1):169–174. doi: 10.1104/pp.73.1.169. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Douce R., Holtz R. B., Benson A. A. Isolation and properties of the envelope of spinach chloroplasts. J Biol Chem. 1973 Oct 25;248(20):7215–7222. [PubMed] [Google Scholar]
  7. LeBel D., Poirier G. G., Beaudoin A. R. A convenient method for the ATPase assay. Anal Biochem. 1978 Mar;85(1):86–89. doi: 10.1016/0003-2697(78)90277-4. [DOI] [PubMed] [Google Scholar]
  8. Leonard R. T., Hodges T. K. Characterization of Plasma Membrane-associated Adenosine Triphosphase Activity of Oat Roots. Plant Physiol. 1973 Jul;52(1):6–12. doi: 10.1104/pp.52.1.6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Maury W. J., Huber S. C., Moreland D. E. Effects of Magnesium on Intact Chloroplasts : II. CATION SPECIFICITY AND INVOLVEMENT OF THE ENVELOPE ATPase IN (SODIUM) POTASSIUM/PROTON EXCHANGE ACROSS THE ENVELOPE. Plant Physiol. 1981 Dec;68(6):1257–1263. doi: 10.1104/pp.68.6.1257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. McCarty D. R., Keegstra K., Selman B. R. Characterization and localization of the ATPase associated with pea chloroplast envelope membranes. Plant Physiol. 1984 Nov;76(3):584–588. doi: 10.1104/pp.76.3.584. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. McCarty D. R., Selman B. R. Partial purification of a nucleoside triphosphatase from the inner membrane of the chloroplast envelope of pea. Arch Biochem Biophys. 1986 Aug 1;248(2):523–531. doi: 10.1016/0003-9861(86)90505-9. [DOI] [PubMed] [Google Scholar]
  12. McCarty D. R., Selman B. R. Properties of a Partially Purified Nucleoside Triphosphatase (NTPase) from the Chloroplast Envelope of Pea. Plant Physiol. 1986 Apr;80(4):908–912. doi: 10.1104/pp.80.4.908. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Nørby J. G. Coupled assay of Na+,K+-ATPase activity. Methods Enzymol. 1988;156:116–119. doi: 10.1016/0076-6879(88)56014-7. [DOI] [PubMed] [Google Scholar]
  14. Peters J. S., Berkowitz G. A. Studies on the System Regulating Proton Movement across the Chloroplast Envelope : Effects of ATPase Inhibitors, Mg, and an Amine Anesthetic on Stromal pH and Photosynthesis. Plant Physiol. 1991 Apr;95(4):1229–1236. doi: 10.1104/pp.95.4.1229. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Sabnis D. D., Gordon M., Galston A. W. Localization of adenosine triphosphatase activity on the chloroplast envelope in tendrils of Pisum sativum. Plant Physiol. 1970 Jan;45(1):25–32. doi: 10.1104/pp.45.1.25. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Schwartz A., Whitmer K., Grupp G., Grupp I., Adams R. J., Lee S. W. Mechanism of action of digitalis: is the Na,K-ATPase the pharmacological receptor? Ann N Y Acad Sci. 1982;402:253–271. doi: 10.1111/j.1749-6632.1982.tb25746.x. [DOI] [PubMed] [Google Scholar]
  17. Werdan K., Heldt H. W., Milovancev M. The role of pH in the regulation of carbon fixation in the chloroplast stroma. Studies on CO2 fixation in the light and dark. Biochim Biophys Acta. 1975 Aug 11;396(2):276–292. doi: 10.1016/0005-2728(75)90041-9. [DOI] [PubMed] [Google Scholar]
  18. Wu W., Berkowitz G. A. Lidocaine and ATPase inhibitor interaction with the chloroplast envelope. Plant Physiol. 1991 Dec;97(4):1551–1557. doi: 10.1104/pp.97.4.1551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Wu W., Berkowitz G. A. Stromal pH and Photosynthesis Are Affected by Electroneutral K and H Exchange through Chloroplast Envelope Ion Channels. Plant Physiol. 1992 Feb;98(2):666–672. doi: 10.1104/pp.98.2.666. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES