We investigate by means of molecular dynamics simulations stretch-induced stepwise translocation of single-stranded DNA (ssDNA) through graphene nanopores. The intrinsic stepwise DNA motion, found to be largely independent of size and shape of the graphene nanopore, is brought about through alternating conformational changes between spontaneous adhesion of DNA bases to the rim of the graphene n...

Using single-molecule fluorescence microscopy and particle-tracking techniques, we elucidate the role DNA topology plays in the diffusion and conformational dynamics of crowded DNA molecules. We focus on large (115 kbp), double-stranded ring and linear DNA crowded by varying concentrations (040%) of dextran (10, 500 kDa) that mimic cellular conditions. By tracking the center-of-mass and measuri...

Single-stranded DNA (ssDNA) is characterized by high conformational flexibility that allows these molecules to adopt a variety of conformations. Here we used native polyacrylamide gel electrophoresis (PAGE), circular dichroism (CD) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy to show that cytosine methylation at CpG sites affects the conformational flexibility of short ssDNA m...

Fabricated solid-state nanopore chips are used to probe individual single stranded DNA (ssDNA) homopolymers. Based on the analysis of the current blockage caused by DNA translocation through a voltage-biased nanopore, we discovered that the hydrodynamic diameter of ssDNA homopolymer helix is comparable to that of double stranded DNA (dsDNA) helix. This proof-of-principle demonstration shows tha...

For biologically relevant macromolecules such as intrinsically disordered proteins, internal degrees of freedom that allow for shape changes have a large influence on both the motion and function compound. A detailed understanding effect flexibility is needed in order to explain their behavior. Here, we study model system freely-jointed chains three six colloidal spheres, using simulations expe...

Familial benign hypercalcemia (FBH) and neonatal hyperparathyroidism (NHPT) are disorders of calcium homeostasis that are associated with missense mutations of the calcium-sensing receptor (CaR). We have undertaken studies to characterize such CaR mutations in FBH and NHPT and to explore methods for their more rapid detection. Nine unrelated kindreds (39 affected, 32 unaffected members) with FB...

Single-stranded DNA (ssDNA) is notable for its interactions with ssDNA binding proteins (SSBs) during fundamentally important biological processes including DNA repair and replication. Previous work has begun to characterize the conformational and electrostatic properties of ssDNA in association with SSBs. However, the conformational distributions of free ssDNA have been difficult to determine....

Research on change-point detection, the classical problem of detecting abrupt changes in sequential data, has focused predominantly on datasets with a single observable. A growing number of time series datasets, however, involve many observables, often with the property that a given change typically affects only a few of the observables. We introduce a general statistical method that, given man...