Elastin is a protein of the extracellular matrix that contributes significantly to the elasticity of connective tissues. In this study, we examine dynamical and structural modifications of aortic elastin exposed to cholesterol by NMR spectroscopic and relaxation methodologies. Macroscopic measurements are also presented and reveal that cholesterol treatment may cause a decrease in the stiffness of tissue. 2H NMR relaxation techniques revealed differences between the relative populations of water that correlate with the swelling of the tissue following cholesterol exposure. 13C magic-angle-spinning NMR spectroscopy and relaxation methods indicate that cholesterol treated aortic elastin is more mobile than control samples. Molecular dynamics simulations on a short elastin repeat VPGVG in the presence of cholesterol are used to investigate the energetic and entropic contributions to the retractive force, in comparison to the same peptide in water. Peptide stiffness is observed to reduce following cholesterol exposure due to a decrease in the entropic force.
Bibliographical noteFunding Information:
G.S.B. acknowledges support from the National Institutes of Health under award number 2SC1GM086268 . Y. Z. acknowledges support from Kenneth R. Lutchen Distinguished Fellowship from the College of Engineering, Student Research Award from the Undergraduate Research Opportunities Program (UROP) at Boston University, National Science Foundation grants CMMI 1100791 (Research Experiences for Undergraduates) and CMMI 1463390 . Collection of data at the New York Structural Biology Center was made possible by a grant from NYSTAR.This research was supported, in part, under National Science Foundation Grants CNS-0958379, CNS-0855217, ACI-1126113 and the City University of New York High Performance ComputingCenter at the College of Staten Island.
- C MAS NMR
- H NMR