scholarly journals Role of Nitric Oxide-Detoxifying Enzymes in the Virulence of Pseudomonas aeruginosa against the Silkworm, Bombyx mori

2013 ◽  
Vol 77 (4) ◽  
pp. 2013E1-2013E1
Author(s):  
Hiroyuki ARAI ◽  
Kazuhiro IIYAMA
Keyword(s):  
Nitric Oxide ◽  
Pseudomonas Aeruginosa ◽  
Bombyx Mori ◽  
Detoxifying Enzymes

New insights into the activity of Pseudomonas aeruginosa cd1 nitrite reductase

2008 ◽  
Vol 36 (6) ◽  
pp. 1155-1159 ◽  
Author(s):  
Serena Rinaldo ◽  
Alessandro Arcovito ◽  
Giorgio Giardina ◽  
Nicoletta Castiglione ◽  
Maurizio Brunori ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pseudomonas Aeruginosa ◽  
Nitrite Reductase ◽  
Nitrite Reduction ◽  
Nitrite Reductases ◽  
Cytochrome Cd1 ◽  
Haem Iron ◽  
Shed Light ◽  
Denitrification Process

The cytochrome cd1 nitrite reductases are enzymes that catalyse the reduction of nitrite to nitric oxide (NO) in the bacterial energy conversion denitrification process. These enzymes contain two different redox centres: one covalently bound c-haem, which is reduced by external donors, and one peculiar d1-haem, where catalysis occurs. In the present paper, we summarize the current understanding of the reaction of nitrite reduction in the light of the most recent results on the enzyme from Pseudomonas aeruginosa and discuss the differences between enzymes from different organisms. We have evidence that release of NO from the ferrous d1-haem occurs rapidly enough to be fully compatible with the turnover, in contrast with previous hypotheses, and that the substrate nitrite is able to displace NO from the d1-haem iron. These results shed light on the mechanistic details of the activity of cd1 nitrite reductases and on the biological role of the d1-haem, whose presence in this class of enzymes has to date been unexplained.

scholarly journals Effect of Superoxide Dismutase Gene Inactivation on Virulence of Pseudomonas aeruginosa PAO1 toward the Silkworm, Bombyx mori

2007 ◽  
Vol 73 (5) ◽  
pp. 1569-1575 ◽  
Author(s):  
Kazuhiro Iiyama ◽  
Yuuka Chieda ◽  
Jae Man Lee ◽  
Takahiro Kusakabe ◽  
Chisa Yasunaga-Aoki ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Superoxide Dismutase ◽  
Bombyx Mori ◽  
Double Mutant ◽  
Microscopic Analysis ◽  
Infection Process ◽  
Lag Phase ◽  
Superoxide Dismutase Gene ◽  
Silkworm Bombyx Mori

ABSTRACT To investigate the role of superoxide dismutase (SOD) in virulence against the silkworm, Bombyx mori, mutants of Pseudomonas aeruginosa PAO1 lacking manganese-SOD (PAO1sodM), iron-SOD (PAO1sodB), or both (PAO1sodMB) were generated. The mutants were injected into the hemocoel of B. mori. The virulence decreased in the order PAO1 = PAO1sodM > PAO1sodB > PAO1sodMB. In particular, PAO1sodMB was avirulent at a dose of 105 cells or less. The sod double mutant PAO1sodMB was then complemented with either pSodM or pSodB in trans. In both the complemented strains, the virulence was partially restored. Of the two plasmids, pSodB contributed more to the virulence of P. aeruginosa against B. mori. The results of growth in B. mori hemolymph broth and microscopic analysis suggested that a longer lag phase and superoxide sensitivity correlated with decreased virulence in sod mutants. In conclusion, the SODs are required for full virulence of P. aeruginosa against B. mori and Fe-SOD is more important than Mn-SOD in the infection process.

A critical role of iNOS-derived Nitric Oxide (NO) and progesterone in implantation

1998 ◽  
Vol 5 (1) ◽  
pp. 115A-115A
Author(s):  
K CHWALISZ ◽  
E WINTERHAGER ◽  
T THIENEL ◽  
R GARFIELD
Keyword(s):  
Nitric Oxide ◽  
Critical Role
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