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J. Biol. Chem., Vol. 281, Issue 47, 38, November 24, 2006
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Classics
Role of Hemoprotein P-450 in Fatty Acid 
-Hydroxylation in a Soluble Enzyme System from Liver Microsomes
(Lu, A. Y. H., and Coon, M. J. (1968) J. Biol. Chem. 243, 1331–1332)
Properties of Electrophoretically Homogeneous Phenobarbital-inducible and 
-Naphthoflavone-inducible Forms of Liver Microsomal Cytochrome P-450
(Haugen, D. A., and Coon, M. J. (1976) J. Biol. Chem. 251, 7929–7939)
Minor Jesser (Jud) Coon was born in 1921 in Englewood, Colorado. He attended the University of Colorado and worked in Reuben Gustavson's laboratory studying steroid hormones. Coon recalls, "I had a tremendous amount to learn but was fascinated from then on with research and the possibility of making new discoveries" (1). Coon received his B.A. in 1943 and went on to do graduate studies with Journal of Biological Chemistry (JBC) Classics author William C. Rose (2) at the University of Illinois. When he arrived at Urbana, Coon was given the project of isolating, purifying, and analyzing amino acids and then feeding them to fellow students in experiments involving daily nitrogen balance determinations. The resulting papers established the quantitative requirements for the essential amino acids, the availability of some of the D-isomers or N-acetyl derivatives, and the role of cysteine and tyrosine in sparing methionine and phenylalanine, respectively.
Coon received his Ph.D. in 1946 and remained at the University of Illinois to do postdoctoral research for the next year. In 1947 he joined the faculty of the Department of Physiological Chemistry at the University of Pennsylvania, where he undertook studies on amino acid metabolism, focusing mostly on leucine, isoleucine, and valine. Through a series of experiments he was able to determine how leucine metabolism is integrated into the main pathways of lipid metabolism and steroid biosynthesis.
Coon stayed at the University of Pennsylvania for several years and was promoted to Assistant Professor in 1949 and Associate Professor in 1953. He moved to the University of Michigan Medical School in 1955 when he was offered a position as Professor in the Department of Biological Chemistry. He served as chairman of the Department of Biological Chemistry from 1970 to 1990. Coon remains at the University of Michigan as Victor C. Vaughan Distinguished University Professor of Biological Chemistry, a position he has held since 1983.
After joining the faculty at the University of Michigan Coon decided to work on the oxidation of hydrocarbons. He purified and characterized an alkane and fatty acid hydroxylase system from Pseudomonas oleovorans. This set the stage for his studies with mammalian systems. Coon and his postdoctoral fellow Anthony Lu undertook the purification of the fatty acid -hydroxylase from liver microsomes. This is the subject of the first JBC Classic reprinted here.
The hepatic system was resistant to the isolation and purification methods that Coon had used with the pseudomonad, but after 2 years, Coon and Lu were able to solubilize the hydroxylating system with various detergents in the presence of agents to protect against enzyme denaturation by the detergents. Using column chromatography, their preparations yielded a red fraction containing cytochrome P-450, a yellow fraction containing the flavoprotein NADPH-cytochrome P-450 reductase, and a colorless, heat-stable fraction. This last fraction was later shown to contain phospholipids, of which phosphatidylcholine was especially active (3). When mixed and incubated together under precise conditions, the three components yielded a reconstituted enzyme system that converted lauric acid to -hydroxylauric acid in the presence of NADPH and oxygen (4).
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Next, Coon turned his attention to determining whether isozymes of P-450 were present in liver. Coon and his postdoctoral fellow David Haugen eventually obtained evidence that at least four isoforms of P-450 were present in rabbit liver (6). As reported in the second JBC Classic reprinted here, they subsequently purified and characterized the principal phenobarbital-inducible and -naphthoflavone-inducible forms of P-450. This paper established beyond doubt the presence of at least two P-450 isoforms in liver, as evidenced by their different molecular masses, carboxyl-terminal sequences, amino acid compositions, spectral properties, and catalytic activities. Subsequently, more P-450s were identified, including the ethanol-inducible form from liver (7) and unique forms from nasal microsomes (8), as well as numerous other forms from a variety of species, tissues, and organelles by many investigators.1
In recognition of his contributions to science, Coon has received many awards and honors. These include the American Chemical Society's Award in Enzyme Chemistry (1959), the University of Michigan's Distinguished Faculty Achievement Award (1976), the William C. Rose Award in Biochemistry (1978), the Bernard B. Brodie Award in Drug Metabolism (1980), the University of Michigan Distinguished Faculty Lectureship Award in Biomedical Research (1982), the State of Michigan Scientist of the Year Award (1988), the American Society for Pharmacology and Experimental Therapeutics Best Published Paper Award (1989), and the Distinguished Achievement Award from the University of Michigan Medical Center Alumni Society (1993). Coon is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. In addition to his research, Coon has been active in service to the biochemistry community. He was Secretary of the American Society for Biochemistry and Molecular Biology from 1981 to 1984 and President from 1991 to 1992. He was also editor-in-chief of Biochemical Preparations and Microsomes, Drug Oxidations and Chemical Carcinogenesis. Coon has served on the editorial boards of Biochemistry, Molecular Pharmacology, and the Journal of Biological Chemistry.2
FOOTNOTES
1 Additional information on Minor J. Coon's research on P-450 can be found in his JBC Reflections (1). 
2 Biographical information on Minor J. Coon was taken from Refs. 1 and 5.
REFERENCES
-hydroxylation system of liver microsomes into three components. J. Biol. Chem. 244, 3714–3721
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