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pH-Induced interfacial properties of Chaplin E from Streptomyces coelicolor
journal contributionposted on 2017-12-01, 00:00 authored by Mina Dokouhaki, Andrew Hung, Emma PrimeEmma Prime, Greg G Qiao, Li Day, Sally L Gras
Chaplin E, or Chp E, is a surface active peptide secreted by Streptomyces coelicolor that adopts different structures depending on solution pH but the effect of these structures on the interfacial properties of Chp E is not known. In experiments paired with simulations, Chp E was found to display pH-dependent interfacial assembly and surface activity. At pH 3.0, Chp E formed an ordered non-amyloidal interfacial film with high surface activity; while at pH 10.0, Chp E self-assembled into a heterogeneous film containing randomly arranged fibrils at the interface that was less surface active compared to the film formed at pH 3.0. In simulations at pH 10.0, Chp E molecules showed a higher propensity for dimerization within the solution phase, lower rate of adsorption to the interface and tighter inter-molecular associations at the interface, consistent with the lower surface activity and smaller interfacial area coverage per molecule measured at this pH compared to at pH 3.0. A model is presented for the role of Chp E in the developmental differentiation of Streptomyces coelicolor, where Chp E contributes to changes in surface tension at low pH and the formation of fibrils on the surface of aerial hyphae at high pH. Our data also suggest Chp E could be a promising surface active agent with functional activity that can be controlled by pH.
JournalColloids and surfaces B: biointerfaces
Pagination589 - 597
LocationAmsterdam, The Netherlands
Publication classificationC1 Refereed article in a scholarly journal
Copyright notice2017, Elsevier B.V.
CategoriesNo categories selected
Pressure\/area isothermSurface activityCDBAMTEMScience & TechnologyLife Sciences & BiomedicinePhysical SciencesTechnologyBiophysicsChemistry, PhysicalMaterials Science, BiomaterialsChemistryMaterials ScienceCELL-SURFACE PROTEINSCLASS-II HYDROPHOBINSAIR-WATER-INTERFACEAERIAL MORPHOGENESISAIR\/WATER INTERFACEBETA-LACTOGLOBULINMOLECULAR-DYNAMICSFORCE-FIELDFIBRILSDIFFERENTIATION