Vijay Pande, Doctoral Dissertation Advisor (AC)
Training and Validation of a Liquid-Crystalline Phospholipid Bilayer Force Field
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
2016; 12 (12): 5960-5967
We present a united-atom model (gb-fb15) for the molecular dynamics simulation of hydrated liquid-crystalline dipalmitoylphosphatidylcholine (DPPC) phospholipid bilayers. This model was constructed through the parameter-space minimization of a regularized least-squares objective function via the ForceBalance method. The objective function was computed using a training set of experimental bilayer area per lipid and deuterium order parameter. This model was validated by comparison to experimental volume per lipid, X-ray scattering form factor, thermal area expansivity, area compressibility modulus, and lipid lateral diffusion coefficient. These comparisons demonstrate that gb-fb15 is robust to temperature variation and an improvement over the original model for both the training and validation properties.
View details for DOI 10.1021/acs.jctc.6b00801
View details for Web of Science ID 000389866500025
View details for PubMedID 27786477
Non-invasive determination of the complete elastic moduli of spider silks
2013; 12 (3): 262-267
Spider silks possess nature's most exceptional mechanical properties, with unrivalled extensibility and high tensile strength. Unfortunately, our understanding of silks is limited because the complete elastic response has never been measured-leaving a stark lack of essential fundamental information. Using non-invasive, non-destructive Brillouin light scattering, we obtain the entire stiffness tensors (revealing negative Poisson's ratios), refractive indices, and longitudinal and transverse sound velocities for major and minor ampullate spider silks: Argiope aurantia, Latrodectus hesperus, Nephila clavipes, Peucetia viridans. These results completely quantify the linear elastic response for all possible deformation modes, information unobtainable with traditional stress-strain tests. For completeness, we apply the principles of Brillouin imaging to spatially map the elastic stiffnesses on a spider web without deforming or disrupting the web in a non-invasive, non-contact measurement, finding variation among discrete fibres, junctions and glue spots. Finally, we provide the stiffness changes that occur with supercontraction.
View details for DOI 10.1038/NMAT3549
View details for Web of Science ID 000315707200026
View details for PubMedID 23353627
- Shear-induced rigidity in spider silk glands APPLIED PHYSICS LETTERS 2012; 101 (10)