Modulation of the conductance of a 2,2'-bipyridine-functionalized peptidic ion channel by Ni2+.

ABSTRACT: An alpha-helical amphipathic peptide with the sequence H2N-(LSSLLSL)3-CONH2 was obtained by solid phase synthesis and a 2,2'-bipyridine was coupled to its N-terminus, which allows complexation of Ni2+. Complexation of the 2,2'-bipyridine residues was proven by UV/Vis spectroscopy. The peptide helices were inserted into lipid bilayers (nano black lipid membranes, nano-BLMs) that suspend the pores of porous alumina substrates with a pore diameter of 60 nm by applying a potential difference. From single channel recordings, we were able to distinguish four distinct conductance states, which we attribute to an increasing number of peptide helices participating in the conducting helix bundle. Addition of Ni2+ in micromolar concentrations altered the conductance behaviour of the formed ion channe

SUBMITTER: Pilz CS 

PROVIDER: S-EPMC2480505 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature