Deuterium Magic Angle Spinning NMR Used to Study the Dynamics of Peptides Adsorbed onto Polystyrene and Functionalized Polystyrene Surfaces.
Deuterium Magic Angle Spinning NMR Used to Study the Dynamics of Peptides Adsorbed onto Polystyrene and Functionalized Polystyrene Surfaces.
J Phys Chem B. 2011 Jun 8;
Authors: Breen NF, Li K, Olsen GL, Drobny GP
LK?14 is a 14 amino acid peptide which displays a periodic alternation of leucine and lysine amino acids. This "hydrophobic periodicity" has been found to result in an ?-helical secondary structure at air-water interfaces and on both polar and non-polar solid polymer surfaces. In this paper the dynamics of LK?14 peptides, selectively deuterated at a single leucine and adsorbed onto polystyrene and carboxylated polystyrene beads, are studied using 2H Magic Angle Spinning (MAS) solid state NMR over a 100 degree temperature range. We first demonstrate the sensitivity enhancement possible with 2H MAS techniques, which in turn enables us to obtain high quality 2H NMR spectra for selectively deuterated peptides adsorbed onto solid polymer surfaces. An extensive literature shows that the dynamics of leucine side chains are sensitive to the local structural environment of the protein. Therefore the degree to which the dynamics of leucine side chains and the backbone of the peptide LK?14 are influenced by surface proximity and surface chemistry is studied as a function of temperature with 2H MAS NMR. It is found that the dynamics of the leucine side chains in LK?14 depend strongly upon the orientation of the polymer on the surface, which in turn depends on whether the LK?14 peptide adsorbs onto a polar or non-polar surface. 2H MAS line shapes therefore permit probes of surface orientation over a wide temperature range.
PMID: 21650191 [PubMed - as supplied by publisher]
Source:
PubMed