We have synthesized a peptide-based supramolecular building block consisting of a cyclic Arg-Gly-Asp (cRGD) peptide segment and a beta-sheet-forming peptide segment. The block peptide was shown to self-assemble into a cRGD-coated nanoribbon structure, as revealed by circular dichroism (CD), dynamic light scattering (DLS), and transmission electron microscopy (TEM) studies. We have shown that th...

We report a pH-dependent conformational transition in short, defined homopolymeric deoxyadenosines (dA(15)) from a single helical structure with stacked nucleobases at neutral pH to a double-helical, parallel-stranded duplex held together by AH(+)-H(+)A base pairs at acidic pH. Using native PAGE, 2D NMR, circular dichroism (CD) and fluorescence spectroscopy, we have characterized the two differ...

We present the software CDpal that is used to analyze thermal and chemical denaturation data to obtain information on protein stability. The software uses standard assumptions and equations applied to two-state and various types of three-state denaturation models in order to determine thermodynamic parameters. It can analyze denaturation monitored by both circular dichroism and fluorescence spe...

We investigate the thermal denaturation of human serum albumin and the associated solvation using terahertz (THz) spectroscopy in aqueous buffer solution. Far- and near-ultraviolet circular dichroism spectroscopy reveal that the protein undergoes a native (N) to extended (E) state transition at temperature ≤55°C with a marginal change in the secondary and tertiary structure. At 70°C, the protei...

A curated library of circular dichroism spectra of 23 G-quadruplexes of known structure was built and analyzed. The goal of this study was to use this reference library to develop an algorithm to derive quantitative estimates of the secondary structure content of quadruplexes from their experimental CD spectra. Principal component analysis and singular value decomposition were used to character...

yfdX proteins are ubiquitously present in a large number of virulent bacteria. A member of this family of protein in E. coli is known to be up-regulated by the multidrug response regulator. Their abundance in such bacteria suggests some important yet unidentified functional role of this protein. Here, we study the thermal response and stability of yfdX protein STY3178 from Salmonella Typhi usin...

Novel copper(II) coordination compounds with chiral macrocyclic imine ligands derived from R-/S-camphor were asymmetrically synthesized and characterized with the aid of chiroptical spectroscopies. Crystal structures of both enantiomers were determined by single crystal X-ray diffraction analysis. Circular dichroism (CD) spectra were analyzed using a simplified exciton model as well as quantum ...

Stopped-flow circular dichroism and fluorescence spectroscopy are used to characterize the assembly of complexes consisting of plasmid DNA bound to the cationic lipids dimethyldioctadecylammonium bromide and 1, 2-dioleoyl- 3-trimethylammonium-propane and a series of polyamidoamine dendrimers. The kinetics of complexation determined from the stopped-flow circular dichroism measurements suggests ...

The suitability of synchrotron radiation circular dichroism spectroscopy (SRCD) for studying interactions between the tricyclic peptide inhibitor siamycin I and the intact FsrC membrane sensor kinase in detergent micelles has been established. In the present study, tertiary structural changes demonstrate that inhibitor binding occurs at a different, non-overlapping site to the native ligand, GBAP.

Using terahertz time domain spectroscopy we demonstrate tunable polarization rotation and circular dichroism in intrinsically non-chiral planar terahertz metamaterials without twofold rotational symmetry. The observed effect is due to extrinsic chirality arising from the mutual orientation of the metamaterial plane and the propagation direction of the incident terahertz wave.