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Structural Studies of Lipid-free Apolipoprotein A-I


EMSL Project ID
7790

Abstract

Cholesterol is a lipid that is necessary for our body. Only those cholesterol molecules that are in excess in the peripheral cells and blood vessels are the ?bad cholesterol? and need to be transport by the HDL particles to the liver for clearance. The reverse cholesterol transport pathway or the HDL pathway is the major drug target for several major human diseases, including heart disease, diabetes and Alzheimer?s disease. Apolipoprotein A-I (apoAI) is a 243-residue exchangeable apolipoprotein which is the most abundant protein component in HDL (~70%). Depending on the extent of lipidation, apoAI displays a dramatic conformational plasticity and may adopt one of four distinct conformations, including: (1). Lipid-free apoAI conformation (for specific phospholipid-binding). (2). ApoAI on preb-HDL (for specific cholesterol-binding). (3). ApoAI on discoidal HDL (for specific LCAT activation). (4). ApoAI on spherical HDL (for specific HDL-receptor binding). The conformational plasticity indeed enables apoAI to display multiple functions which regulate/direct HDL formation, maturation, transport and metabolism. ApoAI structures at different stages will be critical for our understanding of how HDL is formed, to become mature and then transported into the liver. This knowledge is indeed necessary in designing drugs that target the clearance of the ?bad cholesterol?. This proposal is aimed at solving one of the apoAI conformations, the lipid-free apoAI conformation.

Project Details

Project type
Capability Research
Start Date
2004-06-01
End Date
2006-06-04
Status
Closed

Team

Principal Investigator

Jianjun Wang
Institution
Wayne State University

Team Members

Lei Zhao
Institution
Southern Illinois University

Related Publications

A complete NMR spectral assignment of the lipid-free mouse apolipoprotein A-I (apoAI) C-terminal truncation mutant, apoAI(1-216) Biomol NMR Assign (2007) 1:109–111 DOI 10.1007/s12104-007-9031-2
Apolipoprotein AI tertiary structures determine stability and phospholipidbinding activity of discoidal high-density lipoprotein particles of different sizes Bin Chen, Xuefeng Ren, Tracey Neville, Gray Jerome, David W. Hoyt, Daniel Sparks, Gang Ren, and Jianjun Wang Received 14 November 2008; Revised 25 February 2009; Accepted 26 February 2009 DOI: 10.1002/pro.101 Published online 16 March 2009 proteinscience.org
Chen B, X Ren, T Neville, WG Jerome, DW Hoyt, DL Sparks, G Ren, and J Wang. 2009. "Apolipoprotein AI tertiary structures determine stability and phospholipid-binding activity of discoidal high-density lipoprotein particles of different sizes." Protein Science 18(5):921-935. doi:10.1002/pro.101
Parnell JJ, SJ Callister, G Rompato, CD Nicora, L Pasa-Tolic, A Williamson, and ME Pfrender. 2011. "Time-course analysis of the Shewanella amazonensis SB2B proteome in response to osmotic shock." Proteomics 1(25):, doi:10.1038/srep00025