Interactions of very long-chain saturated fatty acids with serum albumin

Journal of Lipid Research

Stephen Curry¹  Donghui Qin²  Robert Bittman²  Ji-Kyung Choi³  Jet Ho³  James A. Hamilton⁴ 

[1] Biophysics Section, Blackett Laboratory, Imperial College of Science, Technology, and Medicine, London SW7 2BW United Kingdom;Department of Chemistry and Biochemistry, Queens College of the City University of New York, Flushing, NY 11367;Department of Physiology and Biophysics, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118;To whom correspondence should be addressed.;

关键词: fatty acid transport;    lipid-protein interactions;    13C-NMR spectroscopy;    adrenoleukodystrophy;   

DOI  :  

来源: DOAJ

【 摘 要 】

The remarkable binding properties of serum albumin have been investigated extensively, but little is known about an important class of fatty acids, the very long-chain saturated fatty acids (VLCFA; >18 carbons). Although VLCFA are metabolized efficiently in normal individuals, they are markers for and possibly causative agents of several peroxisomal disorders. We studied the binding of [13C]carboxyl-enriched arachidic (C20:0), behenic (C22:0), lignoceric (C24:0), and hexacosanoic (C26:0) acids to bovine serum albumin (BSA) by 13C-NMR spectroscopy. For each VLCFA, the NMR spectra showed multiple signals at chemical shifts previously identified for long-chain fatty acids (12–18 carbons), suggesting stabilization of binding by similar, if not identical, interactions of the fatty acid carboxyl anion with basic amino acid residues. The maximal binding (mol of VLCFA/mol of BSA) and the number of observed binding sites decreased with increasing chain length, from 4–5 for C20:0, 3–4 for C22:0, and 2 for C24:0; we validated our previous conclusion that BSA has only one site for C26:0 (Ho, J. K., H. Moser, Y. Kishimoto, and J. A. Hamilton. 1995. J. Clin. Invest. 96: 1455–1463). Analysis of chemical shifts suggested that the highest affinity sites for VLCFA are low affinity sites for long-chain fatty acids. In competition experiments with 13C-labeled C22:0 (3 mol/mol of BSA) and unlabeled oleic acid, C22:0 bound to BSA in the presence of up to 4 mol of oleic acid/mol of BSA, but 1 mol was shifted into a different site.Our studies suggest that albumin has adequate binding capacity for the low plasma levels of VLCFA with 20 to 26 carbons, but the protein may not be able to bind longer chain VLCFA.

【 授权许可】

Unknown