TY - JOUR
T1 - Lipid bilayer composition can influence the orientation of proteorhodopsin in artificial membranes
AU - Tunuguntla, Ramya
AU - Bangar, Mangesh
AU - Kim, Kyunghoon
AU - Stroeve, Pieter
AU - Ajo-Franklin, Caroline M.
AU - Noy, Aleksandr
PY - 2013/9/17
Y1 - 2013/9/17
N2 - 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.
AB - 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.
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U2 - 10.1016/j.bpj.2013.07.043
DO - 10.1016/j.bpj.2013.07.043
M3 - Article
C2 - 24047990
AN - SCOPUS:84884328443
VL - 105
SP - 1388
EP - 1396
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 6
ER -