HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kim, C. H. Articles by Hollocher, T. C. Search for Related Content PubMed PubMed Citation Articles by Kim, C. H. Articles by Hollocher, T. C. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 259, Issue 4, 2092-2099, 02, 1984

Catalysis of nitrosyl transfer reactions by a dissimilatory nitrite reductase (cytochrome c,d1)

CH Kim and TC Hollocher

The dissimilatory nitrite reductase (cytochrome c,d1) from Pseudomonas aeruginosa was observed at pH 7.5 to catalyze nitrosyl transfer (nitrosation) between [15N]nitrite and several N-nucleophiles or H2 18O, with rate enhancement of the order of 10(8) relative to analogous chemical reactions. The reducing system (ascorbate, N,N,N',N'- tetramethylphenylenediamine) could reduce nitrite (but not NO) enzymatically and had essentially no direct chemical reactivity toward nitrite or NO. The N-nitrosations showed saturation kinetics with respect to the nucleophile and, while exhibiting Vmax values which varied by about 40-fold, nevertheless showed little or no dependence of Vmax on nucleophile pKa. The N-nitrosations and NO-2/H2O-18O exchange required the reducing system, whereas NO/H2O-18O exchange was inhibited by the reducing system. NO was not detected to serve as a nitrosyl donor to N-nucleophiles. These and other kinetic observations suggest that the enzymatic nitrosyl donor is an enzyme-bound species derived from reduced enzyme and one molecule of nitrite, possibly a heme- nitrosyl compound (E-FeII X NO+) for which there is precedence. Nitrosyl transfer to N-nucleophiles may occur within a ternary complex of enzyme, nitrite, and nucleophile. Catalysis of nitrosyl transfer by nitrite reductase represents a new class of enzymatic reactions and may present another example of electrophilic catalysis by a metal center. The nitrosyl donor trapped by these reactions is believed to represent an intermediate in the reduction of nitrite by cytochrome c,d1.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				K. A. Sam, M. J. F. Strampraad, S. de Vries, and S. J. Ferguson Very Early Reaction Intermediates Detected by Microsecond Time Scale Kinetics of Cytochrome cd1-catalyzed Reduction of Nitrite J. Biol. Chem., October 10, 2008; 283(41): 27403 - 27409. [Abstract] [Full Text] [PDF]

				M. E. P. Murphy, S. Turley, and E. T. Adman Structure of Nitrite Bound to Copper-containing Nitrite Reductase from Alcaligenes faecalis. MECHANISTIC IMPLICATIONS J. Biol. Chem., November 7, 1997; 272(45): 28455 - 28460. [Abstract] [Full Text] [PDF]

				J. Stamler, D. Singel, and J Loscalzo Biochemistry of nitric oxide and its redox-activated forms Science, December 18, 1992; 258(5090): 1898 - 1902. [Abstract] [PDF]

				S. J. George, J. W. A. Allen, S. J. Ferguson, and R. N. F. Thorneley Time-resolved Infrared Spectroscopy Reveals a Stable Ferric Heme-NO Intermediate in the Reaction of Paracoccus pantotrophus Cytochrome cd1 Nitrite Reductase with Nitrite J. Biol. Chem., October 20, 2000; 275(43): 33231 - 33237. [Abstract] [Full Text] [PDF]