PCCP Blog

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

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

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