The structure and assembly model of the third transmembrane domain of Slc11a1 in SDS micelles revealed by NMR study of the Leu-substituted peptide
Article first published online: 3 NOV 2011
Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Journal of Peptide Science
Volume 18, Issue 1, pages 45–51, January 2012
How to Cite
Xiao, S., Yang, L. and Li, F. (2012), The structure and assembly model of the third transmembrane domain of Slc11a1 in SDS micelles revealed by NMR study of the Leu-substituted peptide. J. Peptide Sci., 18: 45–51. doi: 10.1002/psc.1414
- Issue published online: 26 DEC 2011
- Article first published online: 3 NOV 2011
- Manuscript Accepted: 3 AUG 2011
- Manuscript Revised: 18 JUL 2011
- Manuscript Received: 10 JUN 2011
- National Natural Science Foundation of China. Grant Numbers: NSFC 20973083, 20934002
Slc11a1 is an integral membrane protein with 12 putative transmembrane domains (TMDs) and functions as a pH-coupled divalent metal cation transporter. The conservation of three negatively charged residues in the TMD3 of Slc11 protein family implies the important role of this domain in the function of the proteins. However, aggregation of the transmembrane peptide in micelles prevents structural study of the peptide in these membrane-mimetic environments by NMR spectroscopy. Here, we characterized the structure, position, and assembly model of Slc11a1-TMD3 (Lys128-Ile151) in SDS micelles by the NMR study of its Leu-substituted peptide. It was found that the two-site substitutions of Ala for Leu residues at positions 136 and 140 of TMD3 disrupt the aggregation without altering the secondary structure of the peptide. The Leu-substituted peptide folds as an α-helix spanning from Leu133 to Gly144 and embedded in the micelles. A Leu zipper is suggested to account for the self-assembly of the wild-type peptide in SDS micelles. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.