Pore forming properties of cecropin-melittin hybrid peptide in a natural membrane.
The pore forming properties of synthetic cecropin-melittin hybrid peptide (Acetyl-KWKLFKKIGAVLKVL-CONH(2); CM15) were investigated by using photoreceptor rod outer segments (OS) isolated from frog retinae obtained by using the whole-cell configuration of the patch-clamp technique. CM15 was applied (and removed) to (from) the OS in approximately 50 ms with a computer-controlled microperfusion system. Once the main OS endogenous conductance was blocked with light, the OS membrane resistance was >or=1 G Omega, allowing high resolution, low-noise recordings. Different to alamethicines, CM15 produced voltage-independent membrane permeabilisation, repetitive peptide application caused a progressive permeabilisation increase, and no single-channel events were detected at low peptide concentrations. Collectively, these results indicate a toroidal mechanism of pore formation by CM15.
Milani
Alberto
A
Dipartimento di Biologia ed Evoluzione, Sezione di Fisiologia e Biofisica, National Institute of Neuroscience and Neuroscience Center, Università di Ferrara, Via L. Borsari 46, I-44100 Ferrara, Italy. alberto.milani@student.unife.it
Benedusi
Mascia
M
Aquila
Marco
M
Rispoli
Giorgio
G
D000595:Amino Acid Sequence; D054807:Cecropins / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry; D007700:Kinetics; D008555:Melitten / Q000737:chemistry*; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000737:chemistry*
D054807:Cecropins; D010455:Peptides; D008555:Melitten