Title
Structural Studies of a Lipid-Binding Peptide from Tunicate Hemocytes with Anti-Biofilm Activity
Author
Osmar N. Silva, Eliane S. F. Alves, César de la Fuente-Núñez, Suzana M. Ribeiro, Santi M. Mandal, Diana Gaspar, Ana S. Veiga, Miguel A. R. B. Castanho, Cesar A. S. Andrade, Jessica M. Nascimento, Isabel C. M. Fensterseifer, William F. Porto, Jose R. Correa, Robert. E. W. Hancock, Suresh Korpole, Aline L. Oliveira, Luciano M. Liao, Octavio L. Franco
Year
2016
Journal
Scientific Reports
Abstract
Clavanins is a class of peptides (23aa) histidine-rich, free of post-translational modifications. Clavanins have been studied largely for their ability to disrupt bacterial membranes. In the present study, the interaction of clavanin A with membranes was assessed by dynamic light scattering, zeta potential and permeabilization assays. We observed through those assays that clavanin A lysis bacterial cells at concentrations corresponding to its MIC. Further, the structure and function of clavanin A was investigated. To better understand how clavanin interacted with bacteria, its NMR structure was elucidated. The solution state NMR structure of clavanin A in the presence of TFE-d3 indicated an α-helical conformation. Secondary structures, based on circular dichroism measurements in anionic sodium dodecyl sulfate (SDS) and TFE (2,2,2-trifluorethanol), in silico lipid-peptide docking and molecular simulations with lipids DPPC and DOPC revealed that clavanin A can adopt a variety of folds, possibly influencing its different functions. Microcalorimetry assays revealed that clavanin A was capable of discriminating between different lipids. Finally, clavanin A was found to eradicate bacterial biofilms representing a previously unrecognized function.
Full Article
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Ligand binding, Biochemistry