Itoh Group Literature Review

Yi Liu and Justine P. Roth 1 From the Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218 Received for publication, May27, 2015, and in revised form, November 10, 2015 Published, JBC Papers in Press, November12, 2015, DOI10.1074/jbc.M115.668038   http://www.jbc.org/content/291/2/948.full The mechanism of ω -6 polyunsaturated fatty acid oxidation by wild-type cyclooxygenase 2 and the Y334F variant, lacking a conserved hydrogen bond to the catalytic tyrosyl radical/tyro- sine, was examined for the first time under physiologically rele- vant conditions. The enzymes show apparent bimolecular rate constants and deuterium kinetic isotope effects that increase in proportion to co-substrate concentrations before converging to limiting values. The trends exclude multiple dioxygenase mech- anisms as well as the proposal that initial hydrogen atom abstraction from the fatty acid is the first irreversible step in catalysis. Temp...

Receivedforpublication,March8,2015,andinrevisedform,April10,2015 Published,JBCPapersinPress,April27,2015,DOI10.1074/jbc.M115.650259 Fange Liu ‡§1,2 , Jiafeng Geng ‡¶1,2,3,4 , Ryan H. Gumpper ‡ , Arghya Barman ‡ , Ian Davis ‡¶ , Andrew Ozarowski 􏰀 , Donald Hamelberg ‡§¶ , and X Aimin Liu ‡§¶5 From the ‡ Department of Chemistry, § Center for Diagnostics and Therapeutics, and ¶ Molecular Basis of Disease Program, Georgia State University, Atlanta, Georgia 30303 and the 􏰀 National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 http://www.jbc.org/content/290/25/15621.full?sid=a5ac4e07-0089-43df-9404-976daf368631 Abstract The rubredoxin motif is present in over 74,000 protein sequences and 2,000 structures, but few have known functions. A secondary, non-catalytic, rubredoxin-like iron site is conserved in 3-hydroxyanthranilate 3,4-dioxygenase (HAO), from single cellular sources but not multicell...