Sergei V Lymar

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Recent evidence indicates that Pseudomonas aeruginosa residing as biofilms in airway mucus of cystic fibrosis (CF) patients is undergoing anaerobic metabolism, a form of growth requiring gene products that are not utilized during aerobic growth. The outer membrane protein, OprF, and the rhl quorum sensing circuit are two previously unrecognized cellular(More)
Mucoid, mucA mutant Pseudomonas aeruginosa cause chronic lung infections in cystic fibrosis (CF) patients and are refractory to phagocytosis and antibiotics. Here we show that mucoid bacteria perish during anaerobic exposure to 15 mM nitrite (NO2) at pH 6.5, which mimics CF airway mucus. Killing required a pH lower than 7, implicating formation of nitrous(More)
Peroxynitrite ion (ONO2-) reacted rapidly with CO2 to form a short-lived intermediate provisionally identified as the ONO2CO2- adduct. This adduct was more reactive in tyrosine oxidation than ONO2- itself and produced 3-nitrotyrosine and 3,3'-dityrosine as the major oxidation products. With tyrosine in excess, the rate of 3-nitrotyrosine formation was(More)
The thermodynamic properties of aqueous nitroxyl (HNO) and its anion (NO(-)) have been revised to show that the ground state of NO(-) is triplet and that HNO in its singlet ground state has much lower acidity, pKa((1)HNO/(3)NO(-)) approximately 11.4, than previously believed. These conclusions are in accord with the observed large differences between (1)HNO(More)
A rigorous mathematical model is developed to describe the distribution of respiration-generated oxidants among reactive sites within the phagolysosomes of leukocytic cells. Reaction parameters include the diffusion coefficient of the oxidant, the intrinsic rate constants for its reaction with the phagosomal membrane and the cell envelopes of entrapped(More)
Issues and Scientific Advances Bruce C. Garrett,*,† David A. Dixon,*,‡ Donald M. Camaioni,† Daniel M. Chipman,§ Mark A. Johnson,# Charles D. Jonah,⊥ Gregory A. Kimmel,† John H. Miller,| Thomas N. Rescigno,X Peter J. Rossky,3 Sotiris S. Xantheas,† Steven D. Colson,† Allan H. Laufer,[ Douglas Ray,† Paul F. Barbara,3 David M. Bartels,§ Kurt H. Becker,∆ Kit H.(More)
Protection from NO gas, a toxic byproduct of anaerobic respiration in Pseudomonas aeruginosa, is mediated by nitric oxide (NO) reductase (NOR), the norCB gene product. Nevertheless, a norCB mutant that accumulated approximately 13.6 microM NO paradoxically survived anaerobic growth. Transcription of genes encoding nitrate and nitrite reductases, the enzymes(More)
Higher oxidation states of the mu-oxo bridged ruthenium "blue dimer" ([Ru(bpy)(2)(OH(2))](2)O(4+)) have been characterized by redox titration measurements, resonance Raman (RR) spectroscopy, EPR spectrometry, and pulse radiolysis. The cumulative results indicate that the progression of accessible oxidation states in acidic media is {3,3} --> {3,4} --> {4,4}(More)
The toxicity of peroxynitrite toward Escherichia coli (expressed as LD50, the concentration required to kill 50% of the bacteria) was found to be independent of bacterial cell densities over a wide experimental range, spanning 10(6)-10(10) colony-forming units/mL; the magnitude of LD50 was also pH-independent over the range pH 5.9-8.3. This highly unusual(More)