Effects of membrane channel-forming polypeptides on mitochondrial oxidative phosphorylation. A comparison of alamethicin, gramicidin A, melittin and tetraacetyl melittin

Das, MK and Basu, A and Balaram, P (1985) Effects of membrane channel-forming polypeptides on mitochondrial oxidative phosphorylation. A comparison of alamethicin, gramicidin A, melittin and tetraacetyl melittin. In: Biochemistry International, 11 (3). 357 -363.

Full text not available from this repository. (Request a copy)

Abstract

Transmembrane channel-forming polypeptides can function as uncouplers of mitochondrial oxidative phosphorylation. The observed effects are dependent on the phosphate ion (Pi) concentration in the medium. At low Pi (2.5 mM) the order of uncoupling efficiencies is gramicidin A much greater than alamethicin greater than tetraacetyl melittin greater than melittin. The remarkably high activity of gramicidin A suggests insertion of preformed channel dimers into the membrane. It is also suggested that lipid phase association of peptides is necessary in the other cases. At Pi = 100 mM inhibitory effects are observed for alamethicin and tetraacetyl melittin. Less pronounced inhibition is seen for melittin, while no such effect is noted for gramicidin A. The site of inhibition is shown to be complex IV, and the differences in the behavior of the peptides are rationalized in terms of channel structures.

Item Type:	Journal Article
Publication:	Biochemistry International
Publisher:	National Center for Biotechnology Information
Additional Information:	Copy right of this article belongs to National Center for Biotechnology Information.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	20 May 2010 06:48
Last Modified:	20 May 2010 06:48
URI:	http://eprints.iisc.ac.in/id/eprint/27193

Available Versions of this Item

• Effects of membrane channel-forming polypeptides on mitochondrial oxidative phosphorylation. A comparison of alamethicin, gramicidin A, melittin and tetraacetyl melittin. (deposited 20 May 2010 06:48) [Currently Displayed]
  • Effects of membrane channel-forming polypeptides on mitochondrial oxidative phosphorylation. A comparison of alamethicin, gramicidin A, melittin and tetraacetyl melittin. (deposited 20 May 2010 05:02)

Actions (login required)

View Item