Purification and Characterization of Fermodulin, An $Fe^2^+$-Dependent Inhibitor Protein of 3-Hydroxy-3-methylglutaryl-CoA Reductase

Menon, Satish A and Devi, Usha S and Ramasarma, T (1985) Purification and Characterization of Fermodulin, An $Fe^2^+$-Dependent Inhibitor Protein of 3-Hydroxy-3-methylglutaryl-CoA Reductase. In: Archives of Biochemistry and Biophysics, 239 (2). pp. 342-351.

PDF Purification_and_characterization.pdf Restricted to Registered users only Download (994kB) | Request a copy

Abstract

The activity of 3-hydroxy-3-methylglutaryl-CoA (HMGCoA) reductase of rat liver microsomes was inhibited by the addition of $FeS0_4$ and the cytosolic protein, fermodulin. Modulation of the activity was obtained only in the combined presence of $Fe^2^+$ and fermodulin. Using ammonium sulfate fractionation, heat treatment, and chromatography on CM-Sephadex and then on an $Fe^2^+$ Blue Sepharose affinity matrix, fermodulin was purified to homogeneity. The molecular weight of the purified protein, as determined by filtration through a Sephacryl S-200 column, was 58,000. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the protein resolved into two subunits of $M_r$ 43,000 and 28,000. Fermodulin showed ultraviolet absorption and fluorescence spectra typical of tryptophan-containing proteins, and addition of $FeS0_4$ quenched the fluorescence. Using the Millipore filter assay the binding of 1.6 mol $^5^5FeCl_2/mol$ fermodulin was observed in the presence of Tris-HCl buffer. The inhibitory effect of fermodulin at nonsaturating concentrations was potentiated by bicarbonate, $ATP^.Mg$, and $ADP^.Mg$.

Item Type:	Journal Article
Publication:	Archives of Biochemistry and Biophysics
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	15 Jul 2008
Last Modified:	19 Sep 2010 04:47
URI:	http://eprints.iisc.ac.in/id/eprint/14970

Actions (login required)

View Item