Nitric oxide interaction with insect nitrophorins and thoughts on the electron configuration of the FeNO complex

Fa, Walker

doi:10.1016/j.jinorgbio.2004.10.009

Cited by 160 publications

(168 citation statements)

References 250 publications

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“…1) For the case of Fe III /Fe II reduction potentials for the A and B isomers, this difference is expected to be small and difficult to detect, as reported some years ago for the A and B isomers of bovine liver microsomal cytochrome b 5 , where the extrapolated difference in E o for 100% A and 100% B was calculated to be 27 ± 4 mV (51). Such a small contribution from the minor isomer of NP2-M0D1 (< 11% A), with small difference in reduction potential, would be very difficult to observe.…”

Section: Nmr Studies Of the Rate Of Np2-d1a Ferriheme A:b Ratio Equilmentioning

confidence: 97%

“…The displacement reaction was followed at 417 nm using a Perkin Elmer UV/vis Lambda 19 spectrophotometer. The displacement reaction shown in Scheme 3 can be described by the equation: (5) where k obs is the observed first-order displacement rate constant, k off is the histamine dissociation rate constant, k on is the bimolecular rate constant for histamine binding (eq 4), [Hm] …”

Section: Kinetics Of Histamine Binding and Releasementioning

confidence: 99%

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Effect of the N-Terminus on Heme Cavity Structure, Ligand Equilibrium, Rate Constants, and Reduction Potentials of Nitrophorin 2 from Rhodnius prolixus

et al. 2007

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The D1A mutant of recombinant NP2 has been prepared and shown to have the expression-initiation methionine-0 cleaved during expression in E. coli, as is the case for recombinant NP4, where Ala is the first amino acid for the recombinant protein, as well as for the mature native protein. The heme substituent 1 H NMR chemical shifts of NP2-D1A and those of its imidazole, N-methylimidazole and cyanide complexes are rather different from those of NP2-M0D1. This difference is likely due to the much smaller size of the N-terminal amino acid (A) of NP2-D1A, which allows formation of the closed loop form of this protein, as it does for NP4 (Weichsel, A.; Andersen, J. F.; Roberts, S. A.; Montfort, W. R Nature Struct. Biol. 2000, 7, 551-554). The ratio of the two hemin rotational isomers A and B is different for the two proteins, and the rate at which the A:B ratio reaches equilibrium is strikingly different (NP2-M0D1 t 1/2 for heme rotation ∼2 h, NP2-D1A t 1/2 ∼43 h). This difference is consistent with a high stability of the closed loop form of the NP2-D1A protein, and infrequent opening of the loops that could allow heme to at least partially exit the binding pocket in order to rotate about its α,γ-meso axis. Consistent with this, the rates of histamine binding and release to/from NP2-D1A are significantly slower than for NP2-M0D1 at pH 7.5. This work suggests that care must be taken in interpreting data obtained from proteins that carry the expression-initiation M0.The nitrophorins (nitro = NO, phorin = carrier) are a group of NO-carrying heme proteins found in the saliva of at least two species of blood-sucking insects, Rhodnius prolixus, the "kissing bug", which has four such proteins in the adult insect ( 1-5 ) and at least three additional nitrophorins in earlier stages of development (6 , 7 ), and Cimex lectularius, the bedbug, which has only one nitrophorin protein (8 , 9 ). These interesting heme proteins sequester nitric oxide that is produced by a nitric oxide synthase (NOS) present in the cells of the salivary glands that is similar to vertebrate constituitive NOS (10 -12 ). NO is kept stable for long periods of time by binding it as an axial ligand to a ferriheme Fe center (1 , 3 -5 ). Upon injection into the tissues of the victim, NO dissociates, diffuses through the tissues to the nearby capillaries to cause vasodilation and thereby allows more blood to be transported to the site of the wound. At the same time, histamine, whose role is to cause swelling, itching, and initiating the immune response, is released by mast cells and platelets of the victim. In the case of the Rhodnius proteins, this histamine binds to the heme Fe sites of the nitrophorins, hence preventing the insect's detection for a period of time, which allows it to obtain a sufficient blood meal (13). † This work was supported by National Institutes of Health grant HL54826.Address correspondence to: F. Ann Walker, Department of Chemistry, The University of Arizona, Tucson, Arizona 85721-0041, Tel. + +520 621-8645; Fax. ++520 626-93...

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Section: Nmr Studies Of the Rate Of Np2-d1a Ferriheme A:b Ratio Equilmentioning

confidence: 97%

Section: Kinetics Of Histamine Binding and Releasementioning

confidence: 99%

Effect of the N-Terminus on Heme Cavity Structure, Ligand Equilibrium, Rate Constants, and Reduction Potentials of Nitrophorin 2 from Rhodnius prolixus

et al. 2007

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“…The fact that the association of H 4 B, THF and L-arginine with saNOS caused a distortion of the haem along many coordinates, as is the case for mammalian iNOSox and nNOSox, and that bsNOS already displayed these modes with or without substrate and pterin present, indicates that there is selective pressure to conserve these structural modifications of the haem. Haem distortion from planarity is generally believed to ease the oxidation of haem and make the reduction more difficult [47,48]. By analogy to nitrophorins, Li et al [41] suggested that haem distortion of iNOSox may diminish the rate at which the FeIII-NO complex formed at the end of the catalytic cycle and may be reduced to the long-lived FeII-NO inhibitory complex.…”

Section: Low-frequency Region Of the Feii-no Complexes Of Sanos And Bmentioning

confidence: 99%

Interactions between substrates and the haem-bound nitric oxide of ferric and ferrous bacterial nitric oxide synthases

Chartier

Couture

2006

Biochemical Journal

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We report here the resonance Raman spectra of the FeIII-NO and FeII-NO complexes of the bacterial NOSs (nitric oxide synthases) from Staphylococcus aureus and Bacillus subtilis. The haem-NO complexes of these bacterial NOSs displayed Fe-N-O frequencies similar to those of the mammalian NOSs, in presence and absence of L-arginine, indicating that haem-bound NO and L-arginine had similar haem environments in bacterial and mammalian NOSs. The only notable difference between the two types of NOS was the lack of change in Fe-N-O frequencies of the FeIII-NO complexes upon (6R) 5,6,7,8-tetrahydro-L-biopterin binding to bacterial NOSs. We report, for the first time, the characterization of NO complexes with NOHA (N ω -hydroxy-Larginine), the substrate used in the second half of the catalytic cycle of NOSs. In the FeIII-NO complexes, both L-arginine and NOHA induced the Fe-N-O bending mode at nearly the same frequency as a result of a steric interaction between the substrates and the haem-bound NO. However, in the FeII-NO complexes, the Fe-N-O bending mode was not observed and the ν Fe−NO mode displayed a 5 cm −1 higher frequency in the complex with NOHA than in the complex with L-arginine as a result of direct interactions that probably involve hydrogen bonds. The different behaviour of the substrates in the FeII-NO complexes thus reveal that the interactions between haem-bound NO and the substrates are finely tuned by the geometry of the Fe-ligand structure and are relevant to the use of the FeII-NO complex as a model of the oxygenated complex of NOSs.

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“…Moreover, the coupling of heme doming to the protein conformational substates has been shown to be functionally significant in a variety of heme protein systems (10)(11)(12). However, heme ruffling, which is the primary topic of this paper, is the dominant OOP deformation found in c-type cytochromes (4-6, 13) and nitrophorins (14)(15)(16), which are involved in electron and NO transport, respectively.…”

mentioning

confidence: 96%

Investigations of heme distortion, low-frequency vibrational excitations, and electron transfer in cytochrome c

Sun

Benabbas

Zeng

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

115

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Significance To probe the effect of heme ruffling on electron transport, we studied three cytochromes that display wide variation in the heme ruffling distortion. Ruffling is characterized by a low-frequency heme mode in the region 45–60 cm −1 and by a photoreduction cross-section that displays strong variation as a function of the magnitude of the distortion. Given the similarity in the distance between the heme and the nearest aromatic amino acid for all three proteins, the order-of-magnitude changes in photoreduction rate demonstrate that the ruffling coordinate can serve as a control mechanism for electron transport in heme proteins. Major differences in heme ruffling are noted for cytochrome c when bound to the mitochondrial membrane compared with its solution structure.

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Nitric oxide interaction with insect nitrophorins and thoughts on the electron configuration of the FeNO complex

Cited by 160 publications

References 250 publications

Effect of the N-Terminus on Heme Cavity Structure, Ligand Equilibrium, Rate Constants, and Reduction Potentials of Nitrophorin 2 from Rhodnius prolixus

Effect of the N-Terminus on Heme Cavity Structure, Ligand Equilibrium, Rate Constants, and Reduction Potentials of Nitrophorin 2 from Rhodnius prolixus

Interactions between substrates and the haem-bound nitric oxide of ferric and ferrous bacterial nitric oxide synthases

Investigations of heme distortion, low-frequency vibrational excitations, and electron transfer in cytochrome c

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