These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Urea-induced unfolding of Na,K-ATPase as evaluated by electron paramagnetic resonance spectroscopy. Author: Babavali M, Esmann M, Fedosova NU, Marsh D. Journal: Biochemistry; 2009 Sep 29; 48(38):9022-30. PubMed ID: 19694490. Abstract: Urea-induced unfolding of Na,K-ATPase from pig kidney and from shark salt gland was studied by electron paramagnetic resonance (EPR) spectroscopy of a nitroxyl derivative of maleimide covalently attached to sulfhydryl groups which are essential for activity. Urea-induced structural changes lead to the inhibition of Na,K-ATPase activity. Structural changes detected by EPR are reversible over the whole range of urea concentrations (0-8 M), although activity loss is always irreversible. The structure of the cytoplasmic domain is more accessible and more susceptible to perturbations than is the transmembrane sector of the Na,K-ATPase and thus is more sensitive to denaturant. Conformational changes at the active thiol groups of these enzymes indeed take place before unfolding of the enzyme as a whole, together with enzyme inactivation. Na,K-ATPase from pig kidney is more stable not only to thermal denaturation but also to urea-induced denaturation than is the Na,K-ATPase from shark salt gland. Susceptibility of the latter could arise from the nonhomologous regions in the cytoplasmic domain.[Abstract] [Full Text] [Related] [New Search]