An electrochemical investigation of sarcolipin reconstituted into a mercury-supported lipid bilayer

Lucia Becucci, Rolando Guidelli, Christine B. Karim, David D. Thomas, Gianluigi Veglia

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Sarcolipin was incorporated into a lipid bilayer anchored to a mercury electrode through a hydrophilic tetraethyleneoxy chain. The behavior of this tethered bilayer lipid membrane incorporating sarcolipin was investigated by electrochemical impedance spectroscopy and by recording charge versus time curves after potential jumps. When the transmembrane potential starts to become negative on the trans side, evidence is provided that sarcolipin aggregates into ion-conducting pores. Over the range of physiological transmembrane potentials, these pores are permeable to small inorganic anions such as chloride, phosphate, or sulfate but impermeable to inorganic cations such as Na + and K+. Only at transmembrane potentials more negative than ∼-150 mV on the trans side do sarcolipin channels allow the translocation of the latter cations. A tentative relationship between this property of sarcolipin and its regulatory function on Ca-ATPase of sarcoplasmic reticulum is proposed.

Original languageEnglish (US)
Pages (from-to)2678-2687
Number of pages10
JournalBiophysical journal
Volume93
Issue number8
DOIs
StatePublished - Oct 2007

Bibliographical note

Funding Information:
Thanks are due to Ente Cassa di Risparmio di Firenze for financial support through the PROMELAB project.

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