John W. Keller
Professor of Chemistry Emeritus
University of Alaska Fairbanks
John and Sue at John's retirement party (May 2012).

Interests:
Computational chemistry and biochemistry. Properties and spectroscopy of hydrogen bonded complexes. Computational approaches to cyclodextrins. Applications of computational chemistry in undergraduate instruction.

Current Research:
Computational Chemistry. My research students and I have undertaken several computational studies based on student projects in undergraduate classes. These take advantage of the excellent computational chemistry facilities in the Department of Chemistry and Biochemistry, which maintains several servers running a WebMO website, and at UAF's Arctic Region Supercomputing Center, whose Pacman cluster runs Gaussian and other programs. One ongoing project concerns the properties of a carboxylic acid "dimer", a complex of formic acid and trifluoroacetic acid whose gas-phase vibrational spectrum was obtained in our lab. These so-called bidentate complexes contain a cyclic array of hydrogen bonds and donor-accepter interactions like those found in DNA base pairs. One question that still needs to be answered is, Do the hydrogens in this complex exchange between the acids faster or slower compared to symmetric carboxylic acid complexes? And how is hydrogen transfer in this complex affected by rotation of the CF3 group? Does it speed up hydrogen transfer or slow it down?
      Non-covalent interactions like these play a significant role in determining the chemical and biochemical properties of small molecules in the atmosphere. Accurate prediction of the energy content, vibrational and rotational spectra, and geometry of small molecule-target complexes are now possible using high-level computational chemistry methods. Currently I am applying these methods to complexes of sulfur dioxide, a biologically active molecule produced in large amounts by fossil fuel combustion and volcanic emissions.

Click here for a list of: relevant publications.

Research History:
I have done a fair amount of enzymological and structural research on the bacterial vitamin B6-dependent enzyme dialkylglycine decarboxylase (E.C. 4.1.1.64). I started this project in 1976 as a post-doctoral student in Marion O'Leary's lab at the University of Wisconsin-Madison, and continued it at the University of Alaska Fairbanks. Initially I used protein extracts from Burkholderia cepacia that had been produced at the Fermentation Lab of the Department of Biochemistry in Madison. Later, in Fairbanks, we cloned and manually sequenced a 4.1-kb region of the B. cepacia genome, which allowed us to produce and purify the recombinant enzyme from small E. coli cultures. The insert contained the structural gene for dialkylglycine decarboxylase (dgdA) and a gene encoding a LysR-type cis-acting transcriptional regulatory protein (dgdR). This work resulted in publications in Biochemistry, Journal of Molecular Biology, Journal of Biological Chemistry, Biochemical and Biophysical Research Communications, Tetrahedron Letters, Journal of Chromatography, and others. Hans Jansonius and Michael Toney of the Biozentrum of the University of Basel played crucial roles solving the x-ray crystal structure of the enzyme. Michael is now at the University of California-Davis Department of Chemistry. In my lab about 50 graduate, undergraduate, and high school students  have contributed to various aspects of this research. Two U.S. patents, 5,210,025 and 5,356,796, were issued to cover expression and possible use of the genes.

Teaching:
Since I retired, I am no longer teaching. During the period 1979-2011, I taught General Chemistry (105X and 106X), Organic Chemistry (321, 322, and 324), Molecular Modeling (623), Enzymology and Bioorganic Chemistry (622), and Protein Structure and Function (654).

Address:
Department of Chemistry and Biochemistry
University of Alaska Fairbanks
900 Yukon Drive
Fairbanks, AK 99775-6160

Telephone: 907-888-7278
Fax: 907-474-5640
Email: jwkeller@alaska.edu

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