Ultrasonic study of melittin effects on phospholipid model membranes.
AUTOR(ES)
Colotto, A
RESUMO
Low dose effects of melittin on dilute suspensions of dipalmitoylphosphatidylcholine multilamellar vesicles are investigated by studying the acoustic properties of the system. The temperature dependencies of sound velocity and absorption have been measured at 7.2 MHz in the temperature range of 20-55 degrees C, for different peptide/lipid molar ratios, R. The most pronounced effects were observed at R = 5 x 10(-3), in the vicinity of the pretransition, with a simultaneous increase in sound absorption and velocity. This indicates that melittin affects the polar head group region of the bilayer resulting in a decrease in mobility of the polar head groups. A nonmonotonic dependence of the main transition temperature, with an initial decrease followed by an increase as melittin is added, is interpreted as a consequence of a destabilizing action of the interfaces between mellitin-affected clusters and the unaffected phase.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1225977Documentos Relacionados
- Measured effects of diacylglycerol on structural and elastic properties of phospholipid membranes.
- Adsorption of ruthenium red to phospholipid membranes.
- Effects of size of macrocyclic polyamides on their rate of diffusion in model membranes.
- Cytoskeletal protein binding kinetics at planar phospholipid membranes.
- Differential effects of cholesterol and lanosterol on artificial membranes.