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Structure and Stability of the Spinach Aquaporin SoPIP2;1 in Detergent Micelles and Lipid Membranes

Plasencia, Ines; Survery, Sabeen LU ; Ibragimova, Sania; Hansen, Jesper S.; Kjellbom, Per LU ; Helix-Nielsen, Claus; Johanson, Urban LU and Mouritsen, Ole G. (2011) In PLoS ONE 6(2).
Abstract
Background: SoPIP2;1 constitutes one of the major integral proteins in spinach leaf plasma membranes and belongs to the aquaporin family. SoPIP2;1 is a highly permeable and selective water channel that has been successfully overexpressed and purified with high yields. In order to optimize reconstitution of the purified protein into biomimetic systems, we have here for the first time characterized the structural stability of SoPIP2;1. Methodology/Principal Finding: We have characterized the protein structural stability after purification and after reconstitution into detergent micelles and proteoliposomes using circular dichroism and fluorescence spectroscopy techniques. The structure of SoPIP2;1 was analyzed either with the protein... (More)
Background: SoPIP2;1 constitutes one of the major integral proteins in spinach leaf plasma membranes and belongs to the aquaporin family. SoPIP2;1 is a highly permeable and selective water channel that has been successfully overexpressed and purified with high yields. In order to optimize reconstitution of the purified protein into biomimetic systems, we have here for the first time characterized the structural stability of SoPIP2;1. Methodology/Principal Finding: We have characterized the protein structural stability after purification and after reconstitution into detergent micelles and proteoliposomes using circular dichroism and fluorescence spectroscopy techniques. The structure of SoPIP2;1 was analyzed either with the protein solubilized with octyl-beta-D-glucopyranoside (OG) or reconstituted into lipid membranes formed by E. coli lipids, diphytanoylphosphatidylcholine (DPhPC), or reconstituted into lipid membranes formed from mixtures of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPE), 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE), 1-palmitoyl-2-oleoyl-phosphatidylserine (POPS), and ergosterol. Generally, SoPIP2;1 secondary structure was found to be predominantly a-helical in accordance with crystallographic data. The protein has a high thermal structural stability in detergent solutions, with an irreversible thermal unfolding occurring at a melting temperature of 58 degrees C. Incorporation of the protein into lipid membranes increases the structural stability as evidenced by an increased melting temperature of up to 70 degrees C. Conclusion/Significance: The results of this study provide insights into SoPIP2;1 stability in various host membranes and suggest suitable choices of detergent and lipid composition for reconstitution of SoPIP2;1 into biomimetic membranes for biotechnological applications. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS ONE
volume
6
issue
2
publisher
Public Library of Science
external identifiers
  • wos:000287367600005
  • scopus:79951926849
ISSN
1932-6203
DOI
10.1371/journal.pone.0014674
language
English
LU publication?
yes
id
f3d8759b-c31f-45d1-8433-5eefe1ffa650 (old id 1868877)
date added to LUP
2011-04-18 14:17:25
date last changed
2017-08-13 04:09:53
@article{f3d8759b-c31f-45d1-8433-5eefe1ffa650,
  abstract     = {Background: SoPIP2;1 constitutes one of the major integral proteins in spinach leaf plasma membranes and belongs to the aquaporin family. SoPIP2;1 is a highly permeable and selective water channel that has been successfully overexpressed and purified with high yields. In order to optimize reconstitution of the purified protein into biomimetic systems, we have here for the first time characterized the structural stability of SoPIP2;1. Methodology/Principal Finding: We have characterized the protein structural stability after purification and after reconstitution into detergent micelles and proteoliposomes using circular dichroism and fluorescence spectroscopy techniques. The structure of SoPIP2;1 was analyzed either with the protein solubilized with octyl-beta-D-glucopyranoside (OG) or reconstituted into lipid membranes formed by E. coli lipids, diphytanoylphosphatidylcholine (DPhPC), or reconstituted into lipid membranes formed from mixtures of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPE), 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE), 1-palmitoyl-2-oleoyl-phosphatidylserine (POPS), and ergosterol. Generally, SoPIP2;1 secondary structure was found to be predominantly a-helical in accordance with crystallographic data. The protein has a high thermal structural stability in detergent solutions, with an irreversible thermal unfolding occurring at a melting temperature of 58 degrees C. Incorporation of the protein into lipid membranes increases the structural stability as evidenced by an increased melting temperature of up to 70 degrees C. Conclusion/Significance: The results of this study provide insights into SoPIP2;1 stability in various host membranes and suggest suitable choices of detergent and lipid composition for reconstitution of SoPIP2;1 into biomimetic membranes for biotechnological applications.},
  author       = {Plasencia, Ines and Survery, Sabeen and Ibragimova, Sania and Hansen, Jesper S. and Kjellbom, Per and Helix-Nielsen, Claus and Johanson, Urban and Mouritsen, Ole G.},
  issn         = {1932-6203},
  language     = {eng},
  number       = {2},
  publisher    = {Public Library of Science},
  series       = {PLoS ONE},
  title        = {Structure and Stability of the Spinach Aquaporin SoPIP2;1 in Detergent Micelles and Lipid Membranes},
  url          = {http://dx.doi.org/10.1371/journal.pone.0014674},
  volume       = {6},
  year         = {2011},
}