Photoinduced processes in nucleic acids and proteins: concluding remarks
Light induced charge and energy transport in nucleic acids and proteins is the basis of fundamental biological processes such as photosynthesis, vision, DNA-photostability, DNA-photodamage and photosensing.
Paper
Spiers Memorial Lecture
This review gives an overview of the impact of structure on the understanding of photoinduced processes in macromolecules, focusing on systems presented at this Faraday Discussion meeting.
Computational studies on ground and excited state charge transfer properties of peptidomimetics
Charge transfers during excitation and hole migration dynamics after immediate ionization for various terminal group containing ureido-peptides are studied.
The role of water molecules in phototransduction of retinal proteins and G protein-coupled receptors
Water molecules play a critical role during activation of GPCRs, one of the most important class of signalling proteins.
Effect of point mutations on the ultrafast photo-isomerization of Anabaena sensory rhodopsin
Tuning excited state potentials and dynamics of a retinal protein through point mutations.
Protein charge transfer absorption spectra: an intrinsic probe to monitor structural and oligomeric transitions in proteins
The utility of ProCharTS as an intrinsic spectral probe to track protein aggregation and monitor conformational changes is reported.
Photochemical relaxation pathways of S6-methylthioinosine and O6-methylguanosine in solution
The excited-state dynamics of two byproducts resulting from enzymatic reactions of prodrugs in cells and from the interaction of alkylating agents with cellular DNA have been investigated.
Probing the excited state dynamics of Venus: origin of dual-emission in fluorescent proteins
We present studies on a yellow fluorescent protein variant, Venus, and investigate the photophysics behind the dual emission upon UV excitation in fluorescent proteins.
Excited-state dynamics of mononucleotides and DNA strands in a deep eutectic solvent
The photophysics of several mono- and oligonucleotides were investigated in a deep eutectic solvent for the first time.
A QM/MM study of the initial excited state dynamics of green-absorbing proteorhodopsin
Simulations of the photoisomerization in the green-absorbing proteorhodopsin show aborted bicycle pedal mechanism and interaction with tyrosine 200.
Direct observation of the external force mediated conformational dynamics of an IHF bound Holliday junction
We have investigated the isomerization dynamics and plausible energy landscape of 4-way Holliday junctions (4WHJs) bound to integration host factor (IHF, a DNA binding protein), considering the effect of applied external force, by single-molecule FRET methods.
Optically sensing phospholipid induced coil–helix transitions in the phosphoinositide-binding motif of gelsolin
A FRET-based probe reveals that coil–helix transitions in the phospholipid binding sequence of gelsolin occur at physiological phosphatidylinositol-4,5-bisphosphate concentrations.
Paper
Engineered photoproteins that give rise to photosynthetically-incompetent bacteria are effective as photovoltaic materials for biohybrid photoelectrochemical cells
We address concerns that PufX-deficient RCLH1 complexes from photosynthetically-incompetent bacteria may not be suitable as photovoltaic materials for incorporation into biohybrid photoelectrochemical cells.
Optical backbone-sidechain charge transfer transitions in proteins sensitive to secondary structure and modifications
We report the UV-vis absorption originating from protein backbone-sidechain charge transfer transitions in charged amino acids with anionic and cationic sidechains.
Photoinduced formation mechanism of the thymine–thymine (6–4) adduct in DNA; a QM(CASPT2//CASSCF):MM(AMBER) study
Out-of-plane puckering of the C4′ atom forming a new CC bond seems essential for oxetane formation.
Two-dimensional electronic spectroscopy as a tool for tracking molecular conformations in DNA/RNA aggregates
A computational strategy to simulate two-dimensional electronic spectra (2DES) is introduced, which allows characterising ground state conformations of flexible nucleobase aggregates that play a crucial role in nucleic acid photochemistry.
Paper
Adaptation of Rhodopseudomonas acidophila strain 7050 to growth at different light intensities: what are the benefits to changing the type of LH2?
Femto-second time resolved absorption has been used to investigate how the energy transfer properties in the membranes of high-light and low-light adapted cells change as the composition of the LH2 complexes varies.
Exploring oligomeric state of the serotonin1A receptor utilizing photobleaching image correlation spectroscopy: implications for receptor function
Photobleaching image correlation spectroscopy (pbICS) reveals that membrane cholesterol modulates the oligomeric state of the serotonin1A receptor.
Chiral self-assembly of fullerene clusters on CT-DNA templates
Fullerene nanoclusters with a unique cluster size (3–5 nm) interact with DNA forming chiral assemblies, thus perturbing the highly networked structure of CT-DNA.
Photoactivated proton coupled electron transfer in DNA: insights from quantum mechanical calculations
The energetics of the two main proton coupled electron transfer processes that could occur in DNA are determined by means of time dependent-DFT calculations, using the M052X functional and the polarizable continuum model to include solvent effect.
Mechanistic insights into photoinduced damage of DNA and RNA nucleobases in the gas phase and in bulk solution
The mechanistic details of well-known photohydrate lesions are explored using state-of-the-art computational methods.
Adenine radicals generated in alternating AT duplexes by direct absorption of low-energy UV radiation
The absorption of single photons at 266 nm by alternating adenine–thymine duplexes generates, with similar probabilities, both adenine radicals and adenine–thymine photoadducts.
Gold nanorods decorated with a cancer drug for multimodal imaging and therapy
Drug conjugated gold nanorods for combined imaging and chemo-thermal therapy were evaluated using fluorescence and Raman techniques.
Fluorescent excimers and exciplexes of the purine base derivative 8-phenylethynyl-guanine in DNA hairpins
We characterize the ground- and excited-state electronic interactions between nucleobase analog 8-(4′-phenylethynyl)deoxyguanosine, EG, with natural nucleobases and 7-deazaguanine, as well as between adjacent EG base analogs.
Light induced charge and energy transport in nucleic acids and proteins: general discussion
Light induced damage and repair in nucleic acids and proteins: general discussion
Photocrosslinking between nucleic acids and proteins: general discussion
Bionanophotonics: general discussion
About this collection
We are delighted to share with you a selection of the papers which will be presented at our Faraday Discussion on Photoinduced Processes in Nucleic Acids and Proteins taking place in Kerala, India in January 2018. More information about the event may be found here: http://rsc.li/fd2018. Additional articles will be added to the collection as they are published. The final versions of all the articles presented and a record of the live discussions will be published after the event.
Light induced chemical and physical processes in small organic-/inorganic-/bio-molecules have been a subject of experimental and theoretical research for several decades. Recent advances in high resolution spatio-temporal techniques have offered detailed understanding of excited state processes in small molecules. In sharp contrast, however, information on electronic processes in biomolecules such as isolated proteins and DNA (and their complexes) is still in its infancy. Though extremely complicated to uncover, knowledge of photo-excited state processes of such biomolecules in the cellular/biological context is the eventual goal of scientists working in these areas.
Photochemical and photophysical processes in biomolecules are intimately involved in a multitude of functional processes, that include vision, photosynthesis, molecular recognition, gene replication, etc., and can be utilized in areas such as photodynamic therapy. Such processes in DNA are also of interest to both the biological and materials communities as memory devices and structural building blocks. Malign consequences of mis-function in higher life forms can include blindness (retinal pigmentosa), as well as photomutation leading, in DNA, to the primary cause of various types of cancer which (when light induced) can lead to melanomas.