RESUMO
Recently, well-ordered biological materials have been exploited to pattern inorganic nanoparticles into linear arrays that are of particular interest for nanoelectronic applications. In this work, a de novo designed E. coli-expressed polypeptide (previously shown to form highly rectilinear, ß-sheet-containing structures) operates as a template for divalent metal cations. EDX and TEM analysis verify the attachment of platinum ions to the histidine-rich fibril surface, which was designed specifically to facilitate attachment of chemical moieties. Following chemical reduction, TEM further confirms the formation of localized zero-valent metal aggregates with sub-nanometer interparticle spacing.
Assuntos
Materiais Biocompatíveis/síntese química , Nanotecnologia/métodos , Peptídeos/química , Platina/química , Sequência de Aminoácidos , Materiais Biocompatíveis/análise , Cátions Bivalentes/química , Escherichia coli , Histidina/química , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Peptídeos/genética , Engenharia de Proteínas , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Espectrometria por Raios XRESUMO
A de novo, genetically engineered 687 residue polypeptide expressed in E. coli has been found to form highly rectilinear, beta-sheet containing fibrillar structures. Tapping-mode atomic force microscopy, deep-UV Raman spectroscopy, and transmission electron microscopy definitively established the tendency of the fibrils to predominantly display an apparently planar bilayer or ribbon assemblage. The ordered self-assembly of designed, extremely repetitive, high molecular weight peptides is a harbinger of the utility of similar materials in nanoscience and engineering applications.
