October 2011

Chris Raetz (1946—2011)

Retrospective_Raetz_ChrisWith Chris Raetz’s passing, the scientific world lost a polymath, and I lost my oldest friend.

We met as freshmen at Yale University, two very nerdy chemistry majors yearning to excel and to get a date. Chris took notes for me on one occasion when I left campus early on a Friday for the latter purpose; his notes were elegant and clear except for the derivation of the Grabowski Equation of Thermodynamics.

Chris admitted he hadn’t quite understood it either, so I asked the professor in Monday’s class. The professor looked puzzled and then amused, realizing how thoroughly Chris had bamboozled me about an imaginary equation. We became fast friends.

When we realized we were to enter the same medical school, we decided to room together. In early September, I drove a rental van to New Haven, Conn., threw in his stuff on top of mine and walked his mother’s hound while she made lunch for us. Chris confessed that he’d met "the one," the girl of his dreams, having talked to her on the deck of a boat returning from Europe while she threw up over the rail during a storm. Madeline was entering Brandeis, and in ensuing years we double dated and went hiking and camping in the White Mountains and later in the Sierras (see photo).

Chris’ parents were chemists, and his knowledge and feeling for chemistry was profound. At Harvard University, we were both drawn to Eugene Kennedy’s lab and the enterprise of actually purifying the enzymes of lipid metabolism. Postdocs Bill Dowhan and Carlos Hirschberg joined in morning forays for coffee and greasy donuts and shared the passion. After receiving M.D. and Ph.D. degrees and completing an internship year at the Brigham, Chris began his independent studies as a yellow beret in the Public Health Service at the National Institutes of Health and then continued at the University of Wisconsin at Madison, where he met Joanne Stubbe.

Chris possessed an extraordinary breadth of knowledge, from medicine and pharmacology to biochemistry and genetics and on to organic chemistry. His work integrated each of these approaches to lipid metabolism.

In one seminal, elegant experiment, Chris simply pulse-labeled E. coli with 32P, then extracted lipids and ran a two-dimensional TLC. After a brief exposure to film, three prominent spots appeared, corresponding to phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. However, successively longer exposures revealed a galaxy of minor spots, which Chris identified through meticulous chemistry as the intermediates in Lipid A synthesis.

Chris identified the pathway, discovered the gene for each enzyme in the pathway, and purified and crystallized the proteins all the while seeking ligands with pharmacological potential. All this work, begun at Madison, was miraculously nurtured while at Merck and sprung into full blossom when Chris returned to academia at Duke University.

Our lives have been lived in parallel. We each have two daughters, and we each have one daughter who has become a physician. We both settled in countryside retreat homes. And we each, in our own way, spent our lives trying to emulate Eugene Kennedy. Chris came far closer.

Retrospective_Wickner_WilliamWilliam T. Wickner (William.T.Wickner@Dartmouth.edu) is a professor at Dartmouth Medical School.

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