Characterization of the orphan human cytochromes P450

BIOL 181

Katarina Stark, katarina.stark@vanderbilt.edu, Zhong-Liu Wu, Martha V. Martin, Christal D. Sohl, and F. Peter Guengerich. Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University, 646 Robinson Research Building, 23rd and Pierce Avenues, Nashville, TN 37232-0146
Of the 57 known human cytochromes P450 genes, ¼ remain “orphans”; their function, expression, and regulation are still largely unknown. Our list include P450s 2A7, 2S1, 2U1, 2W1, 3A43, 4A22, 4F11, 4F22, 4V2, 4X1, 4Z1, 20A1, and 27C1. We expressed and purified optimized, recombinant P450s 2W1 (1800 nmol/L), 2S1 (600 nmol/L), and 27C1 (1350 nmol/L) in Escherichia coli. 2W1 oxidizes arachidonic acid (at low levels) and carcinogens, e.g. PAHs; no endogenous substrates were found for 2S1 and 27C1. Little is known about 20A1, which exhibits high sequence-similarity with rodent orthologs. 20A1 mRNA was specifically expressed in human brain using Northern blotting. In situ hybridization and RT-PCR of human and rat brain show expression in substantia nigra, and minor expression in hippocampus and amygdala. Optimized P450 20A1 protein has been expressed in E. coli. Characterization and studies of the function is in progress. (Supported by USPHS grants R37 CA090426 and P30 ES000267).

 

Frontiers in Chemical Biology
5:00 PM-7:00 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Biological Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007