Fluorescent Temporin B Derivative and its Binding to Liposomes |
| |
Authors: | Rohit Sood Yegor Domanov Paavo K J Kinnunen |
| |
Institution: | (1) Helsinki Biophysics and Biomembrane Group, Medical Biochemistry, Institute of Biomedicine, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Helsinki, FIN-00014, Finland |
| |
Abstract: | Temporins are short (10–13 amino acids) and linear antimicrobial peptides first isolated from the skin of the European red
frog, Rana temporaria, and are effective against Gram-positive bacteria and Candida albicans. Similarly to other antimicrobial peptides, the association of temporins to lipid membranes has been concluded to underlie
their antimicrobial effects. Accordingly, a detailed understanding of their interactions with phospholipids is needed. We
conjugated a fluorophore (Texas Red) to a Cys containing derivative of temporin B (temB) and investigated its binding to liposomes
by fluorescence spectroscopy. Circular dichroic spectra for the Cys-mutant recorded in the absence and in the presence of
phospholipids were essentially similar to those for temB. A blue shift in the emission spectra and diminished quenching by
ferrocyanide (FCN) of Texas Red labeled temporin B (TRC-temB) were seen in the presence of liposomes. Both of these changes
can be attributed to the insertion of the Texas Red into the hydrophobic region of the bilayer. Resonance energy transfer,
steady state anisotropy, and fluorescence lifetimes further demonstrate the interaction of TRC-temB with liposomes to be enhanced
by negatively charged phospholipids. Instead, cholesterol attenuates the association of TRC-temB with membranes. The interactions
between TRC-temB and liposomes of varying negative surface charge are driven by electrostatics as well as hydrophobicity.
Similarly to native temporin B also TRC-temB forms amyloid type fibers in the presence of negatively charged liposomes. This
property is likely to relate to the cytotoxic activity of this peptide. |
| |
Keywords: | Antimicrobial peptides Texas Red Liposomes Hydrophobicity Fluorescence spectroscopy |
本文献已被 PubMed SpringerLink 等数据库收录! |
|