Reaction of N. europaea Cytochrome c554 with nitric oxide: A kinetic study using laser photoinitiated NO

INOR 209

Matthew D Youngblut, youngbl2@uwm.edu, Dept of Chemistry and Biochemistry, University of Wisconsin - Milwaukee, 3210 N Cramer St, Milwaukee, WI 53211 and A. Andrew Pacheco, apacheco@uwm.edu, Department of Chemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53211.
Cytochrome c554 (cyt c554) from the bacterium Nitrosomonas europaea is a monomeric protein with a molecular weight of ~26 kDa that contains four c-type hemes. It is the physiological electron acceptor for hydroxylamine oxidoreductase (HAO), an enzyme that catalyzes the oxidation of hydroxylamine to nitrite. Recently it was shown that partially or fully reduced cyt c554 can also bind and reduce NO. Herein we present kinetic studies of the reactivity of cyt c554 with NO photogenerated from N,N'-bis(carboxymethyl)-N,N'-dinitroso-1,4-phenylenediamine. Under these conditions NO is generated within 1 ms by a 308 nm laser pulse, which allows the reactions to be monitored on the ms timescale.
 

The Bioinorganic Chemistry Relating to Enzymes and Proteins
7:00 PM-10:00 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Sci-Mix

Division of Inorganic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007