Ca2+ stabilization of respiratory complex I from Escherichia coli. Issue 12 (12th April 2018)

• Record Type: Journal Article
• Authors: Belevich, Galina; Belevich, Nikolai; Knuuti, Juho; Verkhovskaya, Marina
• Is Part Of: FEMS microbiology letters. Volume 365:Issue 12(2018:Jun.)
• Publication Date: 2018-04-12
• Subjects: respiratory Complex I -- enzyme stability -- role of Ca2+; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fny097
• Languages: English
• ISSNs: 0378-1097

Abstract

Abstract: Stability of the membrane-bound and purified H + -translocating NADH:ubiquinone oxidoreductase, Complex I, was studied. The loss of the enzyme activity is strongly increased by alkaline pH and dilution of the sample. Complex I inactivation is prevented specifically by a low concentration of Ca 2+ and/or an intracellular stabilization factor (ISF). The action of both, Ca 2+ and ISF, on Complex I stability is interdependent. The data are discussed in terms of a release of structural Ca 2+ as a reason for Complex I decay and an effect of ISF on the affinity and/or accessibility of Ca 2+ -binding site. Abstract : Calcium ions were found to play a role of keystone in respiratory Complex I structure and an intracellular stabilization factor secures Ca 2+ in the enzyme.