title: Bulk properties of the lipid bilayer are not essential for the thermal stability of Na,K-ATPase from shark rectal gland or pig kidney.
abstract: The thermal stability of Na,K-ATPase from pig kidney is markedly greater than that of Na,K-ATPase from shark salt glands. The role of the lipid bilayer is studied by solubilisation of the membrane-bound enzyme in the nonionic detergent octaethyleneglycoldodecylmonoether (C(12)E(8)), addition of excess dioleylphosphatidylcholine (DOPC) or palmitoyloleylphosphatidylcholine (POPC) and reconstitution of membranes by removal of detergent. At 54°C the reconstituted enzymatically active pig enzyme retains a high thermal stability, and reconstituted shark enzyme retains a low thermal stability, even with a 9-fold excess of DOPC. This result suggests that the origin of the difference in thermal stability is not related to bulk lipid properties of the native membranes.
authors.affiliation: Department of Physiology and Biophysics, Aarhus University, Ole Worms Allé 6, DK-8000 Aarhus, Denmark.
authors.forename: Aida S
authors.initials: AS
authors.lastname: Hansen
authors.forename: Kristian L
authors.initials: KL
authors.lastname: Kraglund
authors.forename: Natalya U
authors.initials: NU
authors.lastname: Fedosova
authors.forename: Mikael
authors.initials: M
authors.lastname: Esmann
mesh_terms: D000818:Animals; D004795:Enzyme Stability; D006358:Hot Temperature; D007668:Kidney / Q000201:enzymology*; D008051:Lipid Bilayers / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D012491:Salt Gland / Q000201:enzymology*; D012754:Sharks; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry*; D013552:Swine
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D000254:Sodium-Potassium-Exchanging ATPase; C017251:1,2-oleoylphosphatidylcholine