A Nobel Prize (2013) was given to Martin Karplus, Michael Levitt and Ari Warshel for "the development of multiscale models for complex chemical systems".
Molecular properties in complex, non-periodic environments are an extremely important part of our life - in biochemistry, in liquid catalysis, in gas-phase catalytic processes, etc.
Current work in the group aims to connect to nuclear magnetic resonance spectroscopies and long-lived nuclear spin states in small molecules, together with the group of Thomas Theis at North Carolina Stare University.
- Zijian Zhou, Jin Yu, Johannes F. P. Colell, Raul Laasner, Angus W. J. Logan, Danila A. Barskiy, Roman V. Shchepin, Eduard Y. Chekmenev, Volker Blum, Warren S. Warren, and Thomas Theis,
Long-Lived 13C2 Nuclear Spin States Hyperpolarized by Parahydrogen in Reversible Exchange at Micro-Tesla Fields,
The Journal of Physical Chemistry Letters 8, 3008-3014 (2017). DOI:10.1021/acs.jpclett.7b00987 .
- T. Theis, G. Ortiz, A. Logan, K. Claytor, Y. Feng, W. Huhn, V. Blum, S. J. Malcolmson, E. Chekmenev, Q. Wang, and W. Warren,
Direct and Cost-Efficient Hyperpolarization of Long-lived Nuclear Spin States on Universal 15N2-Diazirine Molecular Tags
Science Advances 2, e1501438 (2016), DOI: 10.1126/sciadv.1501438 .
The focus in our group is to make the accuracy of direct quantum-mechanical treatments available to predict the function of complex molecules in "real" environments. This is a long-term challenge. In fact, there is more than one challenge.
First, there is the issue of length-, time-, and ensemble average scales for a proper statistical treatment based on quantum mechanical techniques (e.g., density functional theory).
Second, there is the issue of being "accurate enough". The fast, empirical multiscale models (force fields) that are so successfully developed by the community around Karplus, Levitt, Warshel and others cleary have their accuracy limits (they are, after all, empirical). However, a much more expensive "first-principles" approach should deserve its name to be worth the money.
We are therefore working to ensure this accuracy for specific systems for which accurate, reliable experimental reference data exist. Some important background work includes:
- Matti Ropo, Volker Blum, and Carsten Baldauf, Trends for isolated amino acids and dipeptides: Conformation, divalent ion binding, and remarkable similarity of binding to calcium and lead , Scientific Reports 6, 35772 (2016). DOI: 10.1038/srep35772
- Matti Ropo, Markus Schneider, Carsten Baldauf, and Volker Blum,
First-principles data set of 45,892 isolated and cation-coordinated conformers of 20 proteinogenic amino acids
Scientific Data 3, 160009 (2016).
This is, essentially, a complete conformational space study of the 20 most important amino acids and their dipeptides, intended as a long-term "data mine" for spectroscopic studies, benchmark studies, empirical potential generation, etc. We were particularly interested in including the interaction with divalent cations, which, in our view, can be among the more problematic aspects when modeling specific amino acid - cation interactions with empirical potential models. All the amino acid conformations included in this study can be viewed and retrieved in the Berlin ab-initio amino acid DB. In addition, the entire data set is permanently stored and available via a DOI at the NoMaD Data Repository at http://dx.doi.org/10.17172/NOMAD/20150526220502.
- Benchmarking density functionals that open a path to large systems with improved accuracy,
Mariana Rossi, Sucismita Chutia, Matthias Scheffler, and Volker Blum,
Validation Challenge of Density-Functional Theory for Peptides - Example of Ac-Phe-Ala5-LysH+
The Journal of Physical Chemistry A 118 (35), 7349–7359 (2014).
See also Dave Bowler's recent blog entry, also found on Computational Chemistry Highlights.
- Cations and peptides,
C. Baldauf, K. Pagel, S. Warnke, G. von Helden, B. Koksch, V. Blum, M. Scheffler
How Cations Change Peptide Structure
Chemistry - a European Journal 19, 11224-11234 (2013).
- Benchmarking the peptide-water interaction,
S. Chutia, M. Rossi and V. Blum,
Water Adsorption at Two Unsolvated Peptides with a Protonated Lysine Residue: From Self-Solvation to Solvation
The Journal of Physical Chemistry B 116, 14788-14804 (2012).
- Simulations to help understand the basic spectroscopic signature of the classic local "Zundel" vs. "Eigen" structure formed by water molecules around protons:
N. Heine, M. R. Fagiani, M. Rossi, T. Wende, G. Berden, V. Blum and K. R. Asmis
Isomer-Selective Detection of Hydrogen-Bond Vibrations in the Protonated Water Hexamer
Journal of the American Chemical Society 135, 8266-8273 (2013).
There is a host of interesting, societally relevant (even transformative) challenges where a first-principles based understanding of processes at the atomic scale may help guide the development of better macroscopic processes: In life sciences, in energy research, chemical catalysis etc.
The real value of "first-principles" approaches, where they become applicable, is that they promise a real, unbiased and predictive understanding beyond a phenomenologial description. With this understanding, a real, direct interaction with experiment to help focus and improve specific processes is possible. This is our long-term vision for the field.