title: The influence of two-dimensional organization on peptide conformation.
abstract: Molecular crowding plays a significant role in regulating molecular conformation in cellular environments. It is also likely to be important wherever high molecular densities are required, for example in surface-phase studies, in which molecular densities generally far exceed those observed in solution. Using on-surface circular dichroism (CD) spectroscopy, we have investigated the structure of a synthetic peptide assembled into a highly packed monolayer. The immobilized peptide undergoes a structural transition between α-helical and random coil conformation upon changes in pH and ionic concentration, but critically the threshold for conformational change is altered dramatically by molecular crowding within the peptide monolayer. This study highlights the often overlooked role molecular crowding plays in regulating molecular structure and function in surface-phase studies of biological molecules.
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT (UK).
authors.forename: Simon J
authors.initials: SJ
authors.lastname: White
authors.forename: Steven D
authors.initials: SD
authors.lastname: Johnson
authors.forename: Mark A
authors.initials: MA
authors.lastname: Sellick
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bronowska
authors.forename: Peter G
authors.initials: PG
authors.lastname: Stockley
authors.forename: Christoph
authors.initials: C
authors.lastname: Wälti
mesh_terms: D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D055767:Immobilized Proteins / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D009994:Osmolar Concentration; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D055767:Immobilized Proteins; D010455:Peptides
keywords: circular dichroism; coiled coil; molecular crowding; peptide conformation; surface analysis