Abstract
Chlorella virus-encoded membrane protein Kcv represents a new class of potassium channel. This 94-amino acids miniature K+ channel consists of two trans-membrane α-helix domains intermediated by a pore domain that contains a highly conserved K+ selectivity filter. Therefore, as an archetypal K+ channel, the study of Kcv may yield valuable insights into the structure-function relationships underlying this important class of ion channel. Here, we report a series of new properties of Kcv. We first verified Kcv can be synthesized in vitro. By co-synthesis and assembly of wild-type and the tagged version of Kcv, we were able to demonstrate a tetrameric stoichiometry, a molecular structure adopted by all known K+ channels. Most notably, the tetrameric Kcv complex retains its functional integrity in SDS (strong detergent)-containing solutions, a useful feature that allows for direct purification of protein from polyacrylamide gel. Once purified, the tetramer can form single potassium-selective ion channels in a lipid bilayer with functions consistent to the heterologously expressed Kcv. These finding suggest that the synthetic Kcv can serve as a model of virus-encoded K+ channels; and its newly identified properties can be applied to the future study on structure-determined mechanisms such as K+ channel functional stoichiometry.
Original language | English (US) |
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Pages (from-to) | 1027-1034 |
Number of pages | 8 |
Journal | FEBS Letters |
Volume | 581 |
Issue number | 5 |
DOIs | |
State | Published - Mar 6 2007 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology