This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2a01
From Proteopedia
|
Crystal Structure of Lipid-free Human Apolipoprotein A-I
Contents |
Overview
Despite three decades of extensive studies on human apolipoprotein A-I (apoA-I), the major protein component in high-density lipoproteins, the molecular basis for its antiatherogenic function is elusive, in part because of lack of a structure of the full-length protein. We describe here the crystal structure of lipid-free apoA-I at 2.4 A. The structure shows that apoA-I is comprised of an N-terminal four-helix bundle and two C-terminal helices. The N-terminal domain plays a prominent role in maintaining its lipid-free conformation, indicating that mutants with truncations in this region form inadequate models for explaining functional properties of apoA-I. A model for transformation of the lipid-free conformation to the high-density lipoprotein-bound form follows from an analysis of solvent-accessible hydrophobic patches on the surface of the structure and their proximity to the hydrophobic core of the four-helix bundle. The crystal structure of human apoA-I displays a hitherto-unobserved array of positively and negatively charged areas on the surface. Positioning of the charged surface patches relative to hydrophobic regions near the C terminus of the protein offers insights into its interaction with cell-surface components of the reverse cholesterol transport pathway and antiatherogenic properties of this protein. This structure provides a much-needed structural template for exploration of molecular mechanisms by which human apoA-I ameliorates atherosclerosis and inflammatory diseases.
Disease
Known diseases associated with this structure: Amyloidosis, 3 or more types OMIM:[107680], ApoA-I and apoC-III deficiency, combined OMIM:[107680], Corneal clouding, autosomal recessive OMIM:[107680], Hypertriglyceridemia, one form OMIM:[107680], Hypoalphalipoproteinemia OMIM:[107680]
About this Structure
2A01 is a Single protein structure of sequence from Homo sapiens with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of human apolipoprotein A-I: insights into its protective effect against cardiovascular diseases., Ajees AA, Anantharamaiah GM, Mishra VK, Hussain MM, Murthy HM, Proc Natl Acad Sci U S A. 2006 Feb 14;103(7):2126-31. Epub 2006 Feb 1. PMID:16452169
Page seeded by OCA on Thu Feb 21 16:22:18 2008
