This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Peters, J. S. Articles by Berkowitz, G. A. Search for Related Content PubMed PubMed Citation Articles by Peters, J. S. Articles by Berkowitz, G. A. Agricola Articles by Peters, J. S. Articles by Berkowitz, G. A.

Metabolism and Enzymology

Studies on the System Regulating Proton Movement across the Chloroplast Envelope ¹

Effects of ATPase Inhibitors, Mg²⁺, and an Amine Anesthetic on Stromal pH and Photosynthesis

Horticulture Department, Cook College, Rutgers, New Jersey 08903, The State University of New Jersey, New Brunswick, New Jersey 08903

Studies were undertaken to further characterize the spinach (Spinacea oleracea) chloroplast envelope system, which facilitates H⁺ movement into and out of the stroma, and, hence, modulates photosynthetic activity by regulating stromal pH. It was demonstrated that high envelope-bound Mg²⁺ causes stromal acidification and photosynthetic inhibition. High envelope-bound Mg²⁺ was also found to necessitate the activity of a digitoxinand oligomycin-sensitive ATPase for the maintenance of high stromal pH and photosynthesis in the illuminated chloroplast. In chloroplasts that had high envelope Mg²⁺ and inhibited envelope ATPase activity, 2-(diethylamino)-N-(2,6-dimethylphenyl)acetamide was found to raise stromal pH and stimulate photosynthesis. 2-(Diethylamino)-N-(2,6-dimethylphenyl)acetamide is an amine anesthetic that is known to act as a monovalent cation channel blocker in mammalian systems. We postulate that the system regulating cation and H⁺ fluxes across the plastid envelope includes a monovalent cation channel in the envelope, some degree of (envelope-bound Mg²⁺ modulated) H⁺ flux linked to monovalent cation antiport, and ATPase-dependent H⁺ efflux.

This article has been cited by other articles:

				J. Barrero-Gil, A. Rodriguez-Navarro, and B. Benito Cloning of the PpNHAD1 transporter of Physcomitrella patens, a chloroplast transporter highly conserved in photosynthetic eukaryotic organisms J. Exp. Bot., August 1, 2007; 58(11): 2839 - 2849. [Abstract] [Full Text] [PDF]

				C.-P. Song, Y. Guo, Q. Qiu, G. Lambert, D. W. Galbraith, A. Jagendorf, and J.-K. Zhu A probable Na+(K+)/H+ exchanger on the chloroplast envelope functions in pH homeostasis and chloroplast development in Arabidopsis thaliana PNAS, July 6, 2004; 101(27): 10211 - 10216. [Abstract] [Full Text] [PDF]

				B. Fuks and F. Homblé A Voltage-dependent Porin-like Channel in the Inner Envelope Membrane of Plant Chloroplasts J. Biol. Chem., April 28, 1995; 270(17): 9947 - 9952. [Abstract] [Full Text] [PDF]