In:
Zeitschrift für Naturforschung C, Walter de Gruyter GmbH, Vol. 47, No. 11-12 ( 1992-12-1), p. 835-844
Abstract:
Both, Haloferax mediterranei and Haloferax volcanii membranes contain ATPases which are capable of hydrolyzing ATP in presence of Mg 2+ or Mn 2+ . The ATPases require high concentrations 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 Hf. mediterranei and Hf. volcanii, respectively, show different sensitivities to inhibitors of ATP hydrolysis. ATP hydrolysis of isolated Hf. mediterranei ATPase was inhibited by NaN 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 Haloferax mediterranei membranes was not inhibited by DCCD , but [ 14 C]DCCD was bound to a 14 kDa peptide of the isolated, partially purified enzyme. Furthermore, the ATPase was inactivated by preincubation with 7-chloro-4-nitrobenzofurazan (NBD-Cl). The ATPase activity of Hf. volcanii membranes was inhibited by NEM but not by nitrate and NaN 3 . SDS gel electrophoresis of the partially purified enzyme of Haloferax mediterranei showed putative ATPase subunits of 53.5, 49, 42, 22, 21, 14, 12, and 7.5 kDa. Immunoblots showed cross reactivity between a 53 kDa peptide and anti-β (chloroplast F 1 ), as well as between 53, 50 and 47 kDa peptides and an ATPase antibody of Methanosarcina barkeri. The results will be discussed in context with the placement of the archaebacterial ATPases (A-ATPases) between F- and V-ATPases
Type of Medium:
Online Resource
ISSN:
1865-7125
,
0939-5075
DOI:
10.1515/znc-1992-11-1209
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
1992
detail.hit.zdb_id:
2078107-6
SSG:
12
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