Abstract:
:Artificial membrane systems allow researchers to study the structure and function of membrane proteins in a matrix that approximates their natural environment and to integrate these proteins in ex vivo devices such as electronic biosensors, thin-film protein arrays, or biofuel cells. Given that most membrane proteins have vectorial functions, both functional studies and applications require effective control over protein orientation within a lipid bilayer. In this work, we explored the role of the bilayer surface charge in determining transmembrane protein orientation and functionality during formation of proteoliposomes. We reconstituted a model vectorial ion pump, proteorhodopsin, in liposomes of opposite charges and varying charge densities and determined the resultant protein orientation. Antibody-binding assay and proteolysis of proteoliposomes showed physical evidence of preferential orientation, and functional assays verified the vectorial nature of ion transport in this system. Our results indicate that the manipulation of lipid composition can indeed control orientation of an asymmetrically charged membrane protein, proteorhodopsin, in liposomes.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Tunuguntla R,Bangar M,Kim K,Stroeve P,Ajo-Franklin CM,Noy Adoi
10.1016/j.bpj.2013.07.043subject
Has Abstractpub_date
2013-09-17 00:00:00pages
1388-96issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(13)00865-5journal_volume
105pub_type
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