jp6b08499_si_001.pdf (2.53 MB)
Molecular Dynamics of a Hydrated Collagen Peptide: Insights into Rotational Motion and Residence Times of Single-Water Bridges in Collagen
journal contribution
posted on 2016-11-16, 00:00 authored by Monique
C. Tourell, Konstantin I. MomotMagnetic
resonance transverse spin relaxation time constants (T2) of water protons in ordered collagenous tissues
are dependent on the orientation of the tissue relative to the static
magnetic field. This dependence is commonly referred to as the magic
angle (MA) effect and has been attributed to the restricted rotational
motion of icelike water bridges in the hydrated triple-helix collagen
molecule. Understanding of the molecular mechanism of the MA effect
is important for clinical and research applications of magnetic resonance
spectroscopy and imaging to tissues, such as articular cartilage,
tendons, and ligaments. In this work, we have used molecular dynamics
simulations to investigate the subnanosecond time scale dynamics of
single-water bridges in a model collagen peptide. We ascertain the
residence times and the patterns of restricted rotational motion of
water molecules. The key findings are strongly anisotropic rotation
patterns of water molecules at bridge sites and a dynamic, rather
than icelike, nature of the single-water bridges within the individual
triple-helix collagen molecule.