title: Integration of a two-phase partition method into proteomics research on rat liver plasma membrane proteins.
abstract: To comprehensively identify proteins of the rat liver plasma membrane (PM), we have adopted a proteomics strategy that utilizes sucrose density centrifugation in conjunction with aqueous two-phase partition for plasma membrane isolation, followed by SDS-PAGE, mass spectrometry and bioinformatics. Western blot analysis showed that this method results in highly purified plasma membrane fractions, which is a key to successful plasma membrane proteomics. The PM proteins were separated by SDS-PAGE and digested with trypsin. Through nano-ESI-LC MS/MS analysis we identified 428 rat liver membrane proteins, of which 304 had a gene ontology (GO) annotation indicating a cellular component, and 204 (67%) of the latter were known integral membrane proteins or membrane-associated proteins. In addition to proteins known to be associated with the plasma membrane, several hypothetical proteins have also been identified. This study not only provides a tool to study plasma membrane proteins with low levels of contamination, but also provides a data set for proteins of high to moderate abundance in rat liver plasma membranes, thus allowing for more comprehensive characterization of membrane proteins and a better understanding of membrane dynamics.
authors.affiliation: Key Laboratory of Protein Chemistry and Developmental Biology of Education Committee, College of Life Sciences, Hunan Normal University, Changsha, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Cao
authors.forename: Xuanwen
authors.initials: X
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Xia
authors.initials: X
authors.lastname: Peng
authors.forename: Weijun
authors.initials: W
authors.lastname: Hu
authors.forename: Xianchun
authors.initials: X
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.forename: Jingyun
authors.initials: J
authors.lastname: Xie
authors.forename: Songping
authors.initials: S
authors.lastname: Liang
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D005786:Gene Expression Regulation; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D051381:Rats; D015398:Signal Transduction / Q000502:physiology
chemical_list: D008565:Membrane Proteins