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Marine Biology

, Volume 138, Issue 2, pp 259–265 | Cite as

Activity and inhibitor sensitivity of ATPases in the hydrothermal vent tubeworm Riftia pachyptila : a comparative approach

  • S. K. Goffredi
  • J. J. Childress

Abstract

Phosphorylated ATPases may be involved in the effective pH regulation seen in the hydrothermal vent tubeworm Riftia pachyptila. R. pachyptila appears not only to have a large concentration of ATPases, but the main function of these ATPases seems to have shifted from other types of transport, such as Na+ and K+ movement, to the facilitation of H+ elimination. Plume and trophosome ATPase activity for R. pachyptila measured 646.2 ± 29.5 and 481.4 ± 32.0 μmol Pi (inorganic phosphate) g−1 wet wth−1, respectively. Plume tissue ATPase activity (both mass-specific and protein-specific) in R. pachyptila was higher (between 7% and 55%) than the activity measured in any tissue for 7 other shallow- and deep-living species, in this study. This supports the hypothesis that R. pachyptila regulates acid/base balance via high concentrations of H+-ATPases, including Na+/H+ and K+/H+ exchangers and possibly electrogenic H+-ATPases, as evidenced by a higher total ATPase concentration (646 μmol Pi g−1 wet wt h−1), lesser Na+/K+-ATPase activity (13% of the total, as compared to 20−40% found in other animals), and higher H+-ATPase activity (226–264 μmol Pi g−1wet wt h−1). Overall, R. pachyptila appears to demonstrate elevated ATPase activity, with a greater fraction of the enzymes devoted to proton elimination, in order to effectively control its extracellular pH in the face of processes acting to acidify the internal environment.

Keywords

Enzyme Inorganic Phosphate ATPase Activity Main Function Large Concentration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • S. K. Goffredi
    • 1
  • J. J. Childress
    • 2
  1. 1.Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd., Moss Landing, CA 95039, USA e-mail:goffredi@mbari.org Tel.: +1-831-7751853; Fax: +1-831-7751620US
  2. 2.Marine Science Institute and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USAUS

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