The developmentally regulated avian Ch21 lipocalin is an extracellular fatty acid-binding protein

44Citations
Citations of this article
27Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

Ch21, a developmentally regulated extracellular protein expressed in chick embryos and in cultured chondrocytes, was expressed in the baculovirus system, and the recombinant protein was purified to homogeneity by gel-filtration chromatography. Separation of two isoforms was achieved on an ion-exchange column. Previous work had shown that Ch21 belongs to the superfamily of lipocalins, which are transport proteins for small hydrophobic molecules. Studies were performed to identify the Ch21 ligand. By analysis of recombinant Ch21 on native polyacrylamide gel electrophoresis and by Lipidex assay, the binding of fatty acid to the protein was shown and a preferential binding of long-chain unsaturated fatty acids was observed. Both isoforms had the same behavior. The binding was saturable. Stoichiometry was about 0.7 mol of ligand/mol of protein. The protein binds the ligand in its monomeric form. Calculated dissociation constants were 2 x 10 -7 M for unsaturated fatty acids and 5 x 10 -7 M for stearic acid. The binding was specific; other hydrophobic molecules, as retinoic acid, progesterone, prostaglandins, and long-chain alcohols and aldehydes did not bind to the protein. Short-chain fatty acids did not bind to the protein. Ch21, also present in chicken serum, represents the first extracellular protein able to selectively bind and transport fatty acid in extracellular fluids and serum. We propose to rename the Ch21 protein as extracellular fatty acid-binding protein (Ex-FABP).

Cite

CITATION STYLE

APA

Cancedda, F. D., Malpeli, M., Gentili, C., Marzo, V. D., Bet, P., Carlevaro, M., … Cancedda, R. (1996). The developmentally regulated avian Ch21 lipocalin is an extracellular fatty acid-binding protein. Journal of Biological Chemistry, 271(33), 20163–20169. https://doi.org/10.1074/jbc.271.33.20163

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free