The Rideal Conference on Catalysis began yesterday in Cardiff, UK, and has got off to a great start!
Cynthia Friend gave an interesting plenary talk on the catalytic processes in fundamental surface chemistry – highlighting her recent PCCP Perspective article:
The mystery of gold’s chemical activity: local bonding, morphology and reactivity of atomic oxygen
T. A. Baker, Xiaoying Liu and Cynthia M. Friend
Phys. Chem. Chem. Phys., 2011, 13, 34-46
DOI: 10.1039/C0CP01514H, Perspective
Researchers at Rensselaer Polytechnic Institute Discover New Method To Boost Enzymatic Activity
Proteins are critically important to life and the human body. They are also among the most complex molecules in nature, and there is much we still don’t know or understand about them.
One key challenge is the stability of enzymes, a particular type of protein that speeds up, or catalyzes, chemical reactions. Taken out of their natural environment in the cell or body, enzymes can quickly lose their shape and denature. Everyday examples of enzymes denaturing include milk going sour, or eggs turning solid when boiled.
Rensselaer researchers confined lysozyme and other enzymes inside carefully engineered nanoscale holes. Instead of denaturing, these embedded enzymes mostly retained their 3-D structure and exhibited a significant increase in activity. Copyright Rensselaer Polytechnic Institute
Rensselaer Polytechnic Institute Professor Marc-Olivier Coppens has developed a new technique for boosting the stability of enzymes, making them useful under a much broader range of conditions. Coppens confined lysozyme and other enzymes inside carefully engineered nanoscale holes, or nanopores. Instead of denaturing, these embedded enzymes mostly retained their 3-D structure and exhibited a significant increase in activity.
Read full press release: http://news.rpi.edu/update.do?artcenterkey=2851
Read the PCCP paper:
Effects of surface curvature and surface chemistry on the structure and activity of proteins adsorbed in nanopores
Lung-Ching Sang and Marc-Olivier Coppens
Phys. Chem. Chem. Phys., 2011, 13, 6689-6698
Graphene oxide, dispersed in water, can be electrochemically reduced to thin conductive graphene films by adjusting the conductivity of the suspension, say scientists from Australia.
Read this HOT PCCP paper today:
Direct electro-deposition of graphene from aqueous suspensions
M Hilder et al. Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/c1cp20173e
Read this ‘HOT’ PCCP Perspctive review article just published:
Multiscale modeling of soft matter: scaling of dynamics
Dominik Fritz, Konstantin Koschke, Vagelis A. Harmandaris, Nico F. A. van der Vegt and Kurt Kremer
Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/C1CP20247B
This feature article discusses how multiscale simulations combining atomistic and coarse-grained representations require an understanding of how time scales on the two resolution levels are connected.
This article is part of the forthcoming PCCP themed issue on Multiscale Modeling, Guest Edited by Matthias Bickelhaupt, Peter Bolhuis and Lucas Visscher. Look out for the Multiscale Modeling issue coming in May 2011 – sign-up to the PCCP e-alert to recieve it direct to your inbox!
The Perspective article which was a joint collaboration by PNNS and the University of California, Irvine reviews the use of high resolution mass spectrometry (HR-MS) for studying the fundamental chemistry of organic aerosols.
Read the full PhysOrg.com article: Molecular-level analysis of organic particles put in perspective
This Perspective article also featured on the cover of PCCP issue 9!
Full PCCP article:
Molecular chemistry of organic aerosols through the application of high resolution mass spectrometry
Sergey A. Nizkorodov, Julia Laskin and Alexander Laskin
Phys. Chem. Chem. Phys., 2011, 13, 3612-3629
DOI: 10.1039/C0CP02032J
Paul Popelier and his team have used quantum chemical topology (QCT) to reveal the dynamics of atom–atom interactions in a liquid.
Liquid mixtures, such as ethanol–water and methanol–water, are useful for research into molecular studies of the hydrophobic effect, which governs biological structures and plays a role in protein folding. Also, in the case of ethanol, its specific use as a bio-fuel creates an interest in understanding its interaction with water.
The team studied the behaviour of water and ethanol molecules in terms of O-H…O, C-H…O and H…H interactions. They found that the water molecule formed one to six C-H…O and one to four O-H…O interactions as a proton acceptor.
Also, the more localised a dynamical bond critical point distribution, the higher the average electron density at its bond critical points. The formation of multiple C-H…O interactions affected the shape of the oxygen basin of the water molecule. They also found that the hydrogen atoms of water strongly preferred to form H…H interactions with ethanol’s alkyl hydrogen atoms over its hydroxyl hydrogen.
Reference:
The dynamic behavior of a liquid ethanol-water mixture: a perspective from Quantum Chemical Topology
Paul L. A. Popelier et al, Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/c0cp02869j
A recent PCCP article about a new way to use light to predict molecular crystal structure has featured in Science Daily this week.
In the paper, Timothy Korter and colleagues use low-frequency light to predict London-type dispersion forces using solid-state density functional theory.
This work also featured on the cover of issue 10 of PCCP earlier this month.
Read the Science Daily article
See the PCCP paper in full:
Application of London-type dispersion corrections to the solid-state density functional theory simulation of the terahertz spectra of crystalline pharmaceuticals
Matthew D. King, William D. Buchanan and Timothy M. Korter
Phys. Chem. Chem. Phys., 2011, 13, 4250-4259
Further understanding of the processes that occur at the interface between ionic liquids and metal surfaces has been gained following Frank Endres and colleagues study into the 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate/Au(111) interface.
STM images of the herringbone structure of the Au(111) surface.
At −1.2 V versus the Pt quasi-reference, in situ scanning tunnelling microscopy revealed that the Au(111) surface undergoes a reconstruction to to a herringbone superstructure. Atomic force microscopy showed that that multiple ion pair layers are present at the interface, which are dependent on the electrode potential. Finally, electrochemical impedance spectroscopy revealed three distinct processes at the interface, including a capacitive process occurring between −0.84 V and −1.04 V, which is slower than the electrochemical double layer formation, and is thought to be related to the herringbone reconstruction.
Read more about this hot new research here.
Rob Atkin, Natalia Borisenko, Marcel Drüschler, Sherif Zein El Abedin, Frank Endres, Robert Hayes, Benedikt Huber and Bernhard Roling
Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/C0CP02846K
US scientists have described a database of computationally predicted zeolite-like materials
Positions of Si atoms as well as unit cell, space group, density, and number of crystallographically unique atoms were explored in the construction of this database. The database contains over 2.6 M unique structures. Roughly 15% of these are within +30 kJ mol-1 Si of α-quartz, the band in which most of the known zeolites lie.
These structures have topological, geometrical, and diffraction characteristics that are similar to those of known zeolites. The database is the result of refinement by two interatomic potentials that both satisfy the Pauli exclusion principle. The database has been deposited in the publicly available PCOD database.
Read the PCCP article in full:
A Database of New Zeolite-Like Materials
R Pophale, P A Cheeseman and M W Deem
Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/ c0cp02255a
UK researchers can track the early steps of formation of peptide clumps linked to Alzheimer’s disease using the peptide’s fluorescent ability. This could help design effective therapies for the disease at an early stage.
A peptide known as beta-amyloid forms amyloid plaques that are found in Alzheimer’s disease. Scientists believe that the toxicity of the smallest peptide aggregates formed during the earliest stages of the aggregation process contribute to the neurological damage in the disease. But it’s difficult to study the earliest aggregation steps to find out why the peptide starts to clump together.
‘Fluorescence is sensitive to interactions on the Ångström to nanometre scale so it can be used to monitor processes between individual molecules at the early stages of amyloid aggregation,’ explains Rolinski.
The team measured the decay in tyrosine fluorescence at eight different peptide concentrations enabling them to detect early single peptide-peptide interactions, which are invisible in conventional fluorescence experiments. They found that the initial peptide concentration influences what conformation is adopted by individual peptides and determines the rate of their aggregation.
Read the rest of the Chemistry World story by Russell Johnson
Or read the PCCP paper in full:
Beta-amyloid oligomerisation monitored by intrinsic tyrosine fluorescence
Mariana Amaro, David J. S. Birch and Olaf J. Rolinski
Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/c0cp02652b
