The Bacterial Cytochrome P-450 and Irwin C. Gunsalus

Abstract

A Soluble Cytochrome P-450 Functional in Methylene Hydroxylation (Katagiri, M., Ganguli, B. N., and Gunsalus, I. C. (1968) J. Biol. Chem. 243, 3543–3546) Cytochrome P-450cam. I. Crystallization and Properties (Yu, C.-A., Gunsalus, I. C., Katagiri, M., Suhara, K., and Takemori, S. (1974) J. Biol. Chem. 249, 94–101) Irwin Clyde Gunsalus was born in a prairie farm cottage in South Dakota in 1912. After spending 2 years as a chemistry major at South Dakota State College in Brookings, South Dakota, he transferred to Cornell University and received his B.S. in 1935. Intrigued by his undergraduate exposure to the sciences, Gunsalus stayed at Cornell to pursue graduate study in bacteriology with J. M. Sherman. He was awarded a Ph.D. in 1940 for a thesis titled, “The Chemical Nature of Enterococcus Group Antigen.” Gunsalus was then invited to join the faculty of the department, where he remained for 7 years. In 1947, Gunsalus moved to Indiana University to become a professor of bacteriology. Three years later, he was enticed to move yet again. This time he joined the newly developing Department of Microbiology at the University of Illinois in Urbana. In 1955 he became head of the Biochemistry Division in the Department of Chemistry at the university. Gunsalus was a prime figure in the movement of bacteriology into modern microbiology using biochemistry, the physical sciences, molecular biology, and genetics. In his early research on bacterial growth factors, he discovered pyridoxal phosphate and lipoic acid. During his time in Illinois, Gunsalus developed a genetic system for the study of Pseudomonas, dissected the 11-step pathway for terpene breakdown, discovered the first three-component microbial cytochrome P-450 system involved in this pathway, and purified and crystallized the hemoprotein component of cytochrome P-450. Gunsalus' discovery of the three-component cytochrome P-450 system is the subject of the first Journal of Biological Chemistry (JBC) Classic reprinted here. In the paper, Gunsalus reports that he and his colleagues were able to separate the methylene hydroxylase system from Pseudomonas putida into three fractions: a putidaredoxin reductase, putidaredoxin (an iron-sulfur protein), and a soluble cytochrome P-450 (P-450cam). The three enzymes were shown to function together to catalyze the hydroxylation of methylene carbon 5 of camphor. Six years after the Classic was published, Gunsalus reported that he had successfully crystallized cytochrome P-450cam. His purification and crystallization of the enzyme, as well as some of its general properties, are reprinted here as the second JBC Classic. Eventually, Gunsalus and his colleagues published the sequence of bacterial cytochrome P-450 (1Haniu M. Ames L.G. Yasunobu K.T. Shastry B.S. Gunsalus I.C. Amino acid sequence of the Pseudomonas putida cytochrome P-450.J. Biol. Chem. 1982; 257: 12664-12671Abstract Full Text PDF PubMed Google Scholar) and solved its three-dimensional structure (2Poulos T.L. Finzel B.C. Gunsalus I.C. Wagner G.C. Kraut J. The 2.6-Å crystal structure of Pseudomonas putida cytochrome P-450.J. Biol. Chem. 1985; 260: 16122-16130Abstract Full Text PDF PubMed Google Scholar). Currently, Gunsalus is a Professor Emeritus of Biochemistry at the University of Illinois. He has been recognized with numerous honors and awards, including election to the American Academy of Arts and Sciences, the American Academy of Microbiology, and the National Academy of Sciences. He has also received the Mead Johnson Award in Biochemistry, the Selman Waksman Award, and the William C. Rose Award in Biochemistry and Molecular Biology. He served as president of the American Society of Biological Chemists in 1973 and also as president of the Federation of American Societies for Experimental Biology. 1Biographical information on Irwin C. Gunsalus was taken from Refs. 3Coon M.J. Sligar S.G. Irwin C. Gunsalus, versatile and creative scientist.Biochem. Biophys. Res. Commun. 2003; 312: 1-6PubMed Google Scholar and 4Haniu M. Remembrances of Irwin C. Gunsalus—curiosity and humanity.Biochem. Biophys. Res. Commun. 2003; 312: 51-53Crossref Scopus (0) Google Scholar. 1Biographical information on Irwin C. Gunsalus was taken from Refs. 3Coon M.J. Sligar S.G. Irwin C. Gunsalus, versatile and creative scientist.Biochem. Biophys. Res. Commun. 2003; 312: 1-6PubMed Google Scholar and 4Haniu M. Remembrances of Irwin C. Gunsalus—curiosity and humanity.Biochem. Biophys. Res. Commun. 2003; 312: 51-53Crossref Scopus (0) Google Scholar.