Faculty Collaboration Database

Apolipoprotein A-I alpha -helices 7 and 8 modulate high density lipoprotein subclass distribution. J Biol Chem 2002 Mar 22;277(12):9645-54

Date

12/18/2001

Pubmed ID

11744719

DOI

10.1074/jbc.M107883200

Scopus ID

2-s2.0-0037155808 (requires institutional sign-in at Scopus site)   37 Citations

Abstract

Mice have a monodisperse high density lipoprotein (HDL) profile, whereas humans have two major subfractions designated HDL(2) and HDL(3). Human apoA-I transgenic mice exhibit a human-like HDL profile, indicating that the amino acid sequence of apoA-I is a determinant of the HDL profile. Comparison of the primary sequence of mouse and human apoA-I and the previously designated "hinge" domain of apoA-I led us to hypothesize that alpha-helices 7 and 8 (7/8) are determinants of HDL subclass distribution. The following proteins were expressed in Escherichia coli: human apoA-I, T7-hAI; mouse apoA-I, T7-mAI; chimeric human apoA-I containing murine helices 7/8 in place of human helices 7/8, T7-hAI(m7/8); and the reciprocal chimera, T7-mAI(h7/8). The recombinant proteins were examined for their association with human plasma HDL subclasses. The results demonstrated that T7-hAI bound HDL(2) and HDL(3) equally well, whereas T7-mAI bound to HDL(2) preferentially. T7-hAI(m7/8) behaved like T7-mAI, and T7-mAI(h7/8) behaved like T7-hAI. Thus, alpha-helices 7/8 are strong contributors to the pattern of HDL subclass association. Self-association, alpha-helicity, cholesterol efflux, and lecithin-cholesterol acyltransferase activity of the recombinant proteins were also assessed. Human apoA-I self-associates more and activates human lecithin-cholesterol acyltransferase better than mouse apoA-I. These differential characteristics of human and mouse apoA-I are not dependent on helices 7/8.

Author List

Reschly EJ, Sorci-Thomas MG, Davidson WS, Meredith SC, Reardon CA, Getz GS

Author

Mary Sorci Thomas PhD Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Amino Acid Sequence
Animals
Apolipoprotein A-I
Blotting, Western
Cholesterol
Cholesterol, HDL
Circular Dichroism
Cross-Linking Reagents
DNA, Complementary
Dose-Response Relationship, Drug
Electrophoresis, Polyacrylamide Gel
Escherichia coli
Humans
Kinetics
Lipoproteins, HDL
Mice
Molecular Sequence Data
Protein Binding
Protein Conformation
Protein Structure, Secondary
Recombinant Fusion Proteins
Recombinant Proteins
Sequence Homology, Amino Acid