title: Assembling an ion channel: ORF 3a from SARS-CoV.
abstract: Protein 3a is a 274 amino acid polytopic channel protein with three putative transmembrane domains (TMDs) encoded by severe acute respiratory syndrome corona virus (SARS-CoV). Synthetic peptides corresponding to each of its three individual transmembrane domains (TMDs) are reconstituted into artificial lipid bilayers. Only TMD2 and TMD3 induce channel activity. Reconstitution of the peptides as TMD1 + TMD3 as well as TMD2 + TMD3 in a 1 : 1 mixture induces membrane activity for both mixtures. In a 1 : 1 : 1 mixture, channel like behavior is almost restored. Expression of full length 3a and reconstitution into artificial lipid bilayers reveal a weak cation selective (PK ≈ 2 PCl ) rectifying channel. In the presence of nonphysiological concentration of Ca-ions the channel develops channel activity.
authors.affiliation: Institute of Biophotonics, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, 112, Taiwan.
authors.forename: Tze-Hsiang
authors.initials: TH
authors.lastname: Chien
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Chiang
authors.forename: Chin-Pei
authors.initials: CP
authors.lastname: Chen
authors.forename: Petra
authors.initials: P
authors.lastname: Henklein
authors.forename: Karen
authors.initials: K
authors.lastname: Hänel
authors.forename: Ing-Shouh
authors.initials: IS
authors.lastname: Hwang
authors.forename: Dieter
authors.initials: D
authors.lastname: Willbold
authors.forename: Wolfgang B
authors.initials: WB
authors.lastname: Fischer
mesh_terms: D000595:Amino Acid Sequence; D007473:Ion Channels; D008051:Lipid Bilayers / Q000378:metabolism; D045473:Severe acute respiratory syndrome-related coronavirus
chemical_list: D007473:Ion Channels; D008051:Lipid Bilayers