Alfred Bader Award in Bioinorganic or Bioorganic Chemistry

Melissa Kuhnell

Sponsored by Alfred Bader

Eckard Münck, currently a chemistry professor at Carnegie Mellon University, in Pittsburgh, has focused his career on the structure and function of metalloproteins-bridging physics, chemistry, and biology in the process.

The early years of Münck's career were spent establishing Fe Mössbauer spectroscopy as a key technique in the study of metalloproteins. His work showed that this method can provide unique and detailed electronic, structural, and functional information about an iron center in a protein.

He "single-handedly transformed Fe Mössbauer spectroscopy from a mostly unknown and underappreciated technique in the bioinorganic community into, arguably, the most sought-after technique for the study of iron-containing proteins, enzymes, and biomimetic compounds," says Boi-Hanh (Vincent) Huynh, physics professor at Emory University and a former research associate of Münck's.

Münck's protocol for analyzing Mössbauer spectra has become the standard worldwide, and characterization of a biological iron compound is now considered incomplete without the Mössbauer data.

After introducing the M- and P-clusters of nitrogenase through comprehensive Mössbauer studies, Münck used quantum chemical methods to provide a better understanding of the electronic structure of these clusters.

Further work on nitrogenase established the existence of the [₃Fe-4^S] cluster and showed how it could interconvert with [4Fe-4S] clusters-the first time that cluster interconversion was observed for an Fe-S cluster. This work also showed that the substrates bind to the incorporated iron, establishing that [₄Fe-4^S] clusters can function as catalytic centers.

"These studies have laid the groundwork for a burgeoning work on inorganic chemistry of cluster assembly and reactivity. Moreover, this fundamental biophysical work laid the foundations for a more recent explosion in research on the role of Fe-S cluster assembly and destruction in the control of gene expression," says Brian G. Fox, biochemistry professor at the University of Wisconsin, Madison.

Münck has also made substantial contributions to the structural understanding of oxygenase enzymes, including aromatic ring dioxygenases, methane monooxygenase, fatty acid desaturases, and synthetic complexes that mimic the active sites of these enzymes. A recent paper describes the characterization of the first Fe(V)-oxo complex.

Another accomplishment is the recognition that reduced [₃Fe-4^S] clusters contain a valence-delocalized iron pair whose magnetism is dominated by double exchange. Such pairs are also present in the three standard forms of [₄Fe-4^S] clusters.

In addition to his research achievements, Münck has educated and inspired younger bioinorganic chemists. "I can confidently attest that Eckard is an extraordinarily inspiring teacher," Huynh says. "His intense love of science and persistent quest for perfect understanding are contagious and have a profound and long-lasting effect in shaping the attitude of his associates in their pursuit of scientific inquiries."

Münck, 68, received a diploma in physics in 1964 and a Ph.D. in 1967, both from the Technical University of Darmstadt, in Germany. He then worked as a research associate, and later as a research assistant professor, in the department of physics at the University of Illinois. In 1974, Münck moved to the University of Minnesota as an associate professor of biochemistry. There, he was promoted to full professor in 1978 and served as acting director of Gray Freshwater Biological Institute from 1979 to 1981.

Since 1990, Münck has been a professor of chemistry at Carnegie Mellon. He has authored more than 200 publications and has served on the editorial boards of the Journal of Biological Chemistry, the Journal of Inorganic Biochemistry, and Inorganica Chimica Acta. In 1999, he was chair of the Gordon Conference on Metals in Biology.

The award address will be presented before the Division of Inorganic Chemistry.-Melissa Kuhnell