| 2 | Author
| Michaela Dane, Kerstin Steinert, Kordula Esser, Susanne Bickel-Sandkötter, Francisco Rodriguez-Valera | Requires cookie* | | Title
| Properties of the Plasma Membrane ATPases of the Halophilic Archaebacteria Haloferax mediterranei and Haloferax volcanii  | | | Abstract
| Both, Haloferax mediterranei and Haloferax volcanii membranes contain ATPases which are capable of hydrolyzing ATP in presence of Mg2+ or M n2+. The ATPases require high con centrations of NaCl, a pH value of 9, and high temperatures up to 60 °C. Free manganese ions inhibited the enzyme activity of either ATPase. The ATPases of H f. mediterranei and H f. vol canii, respectively, show different sensitivities to inhibitors of ATP hydrolysis. ATP hydrolysis of isolated H f. mediterranei ATPase was inhibited by N aN 3, which was reported to be specific for F-ATPases, by nitrate and N-ethylmaleimide (NEM), which are specific inhibitors of V-ATPases. ATP hydrolysis of H aloferax mediterranei membranes was not inhibited by DCCD , but [14C]DCCD was bound to a 14 kDa peptide of the isolated, partially purified en zyme. Furthermore, the ATPase was inactivated by preincubation with 7-chloro-4-nitro-benzofurazan (NBD-C1). The ATPase activity of H f. volcanii membranes was inhibited by NEM but not by nitrate and N aN 3. SDS gel electrophoresis of the partially purified enzyme of Haloferax mediterranei showed putative ATPase subunits of 53. and 7.5 kDa. Immunoblots showed cross reactivity between a 53 kDa peptide and anti-$ (chloro plast F(), as well as between 53, 50 and 47 kDa peptides and an ATPase antibody of Methano-sarcina barkeri. The results will be discussed in context with the placement of the archaebac-terial ATPases (A-ATPases) between F-and V-ATPases. | | |
Reference
| Z. Naturforsch. 47c, 835—844 (1992); received June 29/September 10 1992 | | |
Published
| 1992 | | |
Keywords
| Archaebacteria, Plasma Membrane, ATPase, Subunits, ATP Hydrolysis, Inhibition | | |
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| default:Reihe_C/47/ZNC-1992-47c-0835.pdf | | | Identifier
| ZNC-1992-47c-0835 | | | Volume
| 47 | |
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