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: Tze-Hsiang Chien, Ya-Ling Chiang, Chin-Pei Chen, Petra Henklein, Karen Hänel, Ing-Shouh Hwang, Dieter Willbold, Wolfgang B Fischer
• Journal: Biopolymers (Biopolymers) Vol. 99 Issue 9 Pg. 628-35 (Sep 2013) ISSN: 1097-0282 [Electronic] United States
• PMID: 23483519 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Wiley Periodicals, Inc.

Chemical References

• Ion Channels
• Lipid Bilayers

Topics

• Amino Acid Sequence
• Ion Channels
• Lipid Bilayers (metabolism)
• Severe acute respiratory syndrome-related coronavirus