52674-29-0Relevant articles and documents
Proton-induced reactivity of NO- from a {CoNO}8 complex
Rhine, Melody A.,Rodrigues, Andria V.,Urbauer, Ramona J. Bieber,Urbauer, Jeffrey L.,Stemmler, Timothy L.,Harrop, Todd C.
, p. 12560 - 12563 (2014)
Research on the one-electron reduced analogue of NO, namely nitroxyl (HNO/NO-), has revealed distinguishing properties regarding its utility as a therapeutic. However, the fleeting nature of HNO requires the design of donor molecules. Metal nit
Tetragonal to triclinic - A phase change for [Fe(TPP)(NO)]
Silvernail, Nathan J.,Olmstead, Marilyn M.,Noll, Bruce C.,Robert Scheldt
, p. 971 - 977 (2009)
The temperature dependence of the crystalline phase of (nitrosyl) (tetraphenylporphinato)iron(II), [Fe(TPP)(NO)], has been explored over the temperature range of 33-293 K. The crystalline complex is found in the tetragonal crystal system at higher tempera
Direct observation of nitrosylated heme in myoglobin and hemoglobin by electrospray ionization mass spectrometry
Upmacis, Rita K.,Hajjar, David P.,Chait, Brian T.,Mirza, Urooj A.
, p. 10424 - 10429 (1997)
Using electrospray ionization mass spectrometry (ESI-MS), we demonstrate the direct observation of NO attached to the heme moiety in;horse heart myoglobin (Mb) and in the α- and β-chains of human hemoglobin (Hb). It was found that a narrow range of ESI-MS conditions conspire to make observation of Fe-NO interactions challenging, and this is presumably the reason why earlier attempts by other research groups to detect intact Fe-NO products by mass spectrometry were unsuccessful For Mb and Hb, mass shifts are observed that are consistent with NO modification of the hemoproteins. ESI mass spectra of the apoprotein portions of Mb and Hb in the presence of NO demonstrated the absence of NO modification of the polypeptide backbones. UV/vis spectra of both Mb/NO and Hb/NO solutions, recorded at the time of ESI-MS analysis, demonstrated hemoprotein(II)-NO formation. To test the hypothesis that intact nitrosylated heme groups are observable by ESI-MS, a nitrosylated model metalloporphyrin was studied. The ESI mass spectrum of nitrosyl-α,β,γ,δ-tetraphenylporphinatoiron(II), [Fe(TPP)NO], showed peaks that were ascribed to [Fe(TPP)]+ and [Fe(TPP)NO]+. To test further our hypothesis that the hemoprotein-NO peaks are due to heme nitrosylation and contain no significant contributions from NO modification of the polypeptide backbone, we determined the ESI-MS conditions necessary for observing S-nitrosation of Cys residues in Hb. Human Hb contains one Cys residue in Hb(α) (Cys 104) and two Cys residues in Hb(β), but only Hb(β) Cys 93 is surface accessible. When metHb was incubated with S-nitroso-N-acetyl-DL-penicillamine (SNAP), the ESI mass spectrum revealed a single SNAP modification in both Hb(β) and apoHb(β). The ESI-MS conditions used for analyzing the Hb/SNAP solution were too harsh for observing intact heme nitrosylation, and thus, we ascribe the SNAP-modified Hb(β) and apoHb(β) peaks to S-nitrosation of Cys 93 in Hb(β). Under appropriate denaturing sample conditions, it proved possible to S-nitrosate all three Cys residues in human apoHb. pur findings demonstrate that (once correct conditions are established) ESI-MS is a powerful tool for the detection of intact Fe-NO interactions in proteins and porphyrins.
To Transfer or Not to Transfer? Development of a Dinitrosyl Iron Complex as a Nitroxyl Donor for the Nitroxylation of an FeIII-Porphyrin Center
Tseng, Yu-Ting,Chen, Chien-Hong,Lin, Jing-Yu,Li, Bing-Han,Lu, Yu-Huan,Lin, Chia-Her,Chen, Hsin-Tsung,Weng, Tsu-Chien,Sokaras, Dimosthenes,Chen, Huang-Yeh,Soo, Yun-Liang,Lu, Tsai-Te
, p. 17570 - 17573 (2015)
A positive myocardial inotropic effect achieved using HNO/NO-, compared with NO· triggered attempts to explore novel nitroxyl donors for use in clinical applications in vascular and myocardial pharmacology. To develop M-NO complexes for nitroxy
High-pressure infrared spectroscopic study of the nitric oxide complex of iron(II)-meso-tetraphenyl porphyrinate
Prémont-Schwarz, Mirabelle,Bohle, D. Scott,Gilson, Denis F.R.
, p. 3089 - 3091 (2006)
The infrared spectrum of iron(II)-meso-tetraphenylporphyrinate (FeTPP(NO)) has been measured as a function of pressure up to 3.1 GPa. The N-O stretching frequency decreases with increasing pressure, as expected for the bonding model for nitric oxide bound to iron in porphyrin complexes. Other peaks in the spectrum show positive pressure dependence.
The role of porphyrin peripheral substituents in determining the reactivities of ferrous nitrosyl species
Amanullah, Sk,Dey, Abhishek
, p. 5909 - 5921 (2020/07/13)
Ferrous nitrosyl {FeNO}7 species is an intermediate common to the catalytic cycles of Cd1NiR and CcNiR, two heme-based nitrite reductases (NiR), and its reactivity varies dramatically in these enzymes. The former reduces NO2- to NO in the denitrification pathway while the latter reduces NO2- to NH4+ in a dissimilatory nitrite reduction. With very similar electron transfer partners and heme based active sites, the origin of this difference in reactivity has remained unexplained. Differences in the structure of the heme d1 (Cd1NiR), which bears electron-withdrawing groups and has saturated pyrroles, relative to heme c (CcNiR) are often invoked to explain these reactivities. A series of iron porphyrinoids, designed to model the electron-withdrawing peripheral substitution as well as the saturation present in heme d1 in Cd1NiR, and their NO adducts were synthesized and their properties were investigated. The data clearly show that the presence of electron-withdrawing groups (EWGs) and saturated pyrroles together in a synthetic porphyrinoid (FeDEsC) weakens the Fe-NO bond in {FeNO}7 adducts along with decreasing the bond dissociation free energies (BDFENH) of the {FeHNO}8 species. The EWG raises the E° of the {FeNO}7/8 process, making the electron transfer (ET) facile, but decreases the pKa of {FeNO}8 species, making protonation (PT) difficult, while saturation has the opposite effect. The weakening of the Fe-NO bonding biases the {FeNO}7 species of FeDEsC for NO dissociation, as in Cd1NiR, which is otherwise set-up for a proton-coupled electron transfer (PCET) to form an {FeHNO}8 species eventually leading to its further reduction to NH4+.
The Thiolate Trans Effect in Heme {FeNO}6 Complexes and Beyond: Insight into the Nature of the Push Effect
Hunt, Andrew P.,Lehnert, Nicolai
supporting information, (2019/04/03)
Cyt P450 nitric oxide (NO) reductase (P450nor) is an important enzyme in fungal denitrification, responsible for the large-scale production of the greenhouse gas N2O. In the first step of catalysis, the ferric heme-thiolate active site of P450nor binds NO to produce a ferric heme-nitrosyl or {FeNO}6 intermediate (in the Enemark-Feltham notation). In this paper, we present the low-temperature preparation of six new heme-thiolate {FeNO}6 model complexes, [Fe(TPP)(SPh?)(NO)], using a unique series of electron-poor thiophenolates (SPh?-), and their detailed spectroscopic characterization. Our data show experimentally, for the first time, that a direct correlation exists between the thiolate donor strength and the Fe-NO and N-O bond strengths, evident from the corresponding stretching frequencies. This is due to a σ-trans effect of the thiolate ligand, which manifests itself in the population of an Fe-N-O σ-antibonding (σ?) orbital. Via control of the thiolate donor strength (using hydrogen bonds), nature is therefore able to exactly control the degree of activation of the FeNO unit in P450nor. Vice versa, NO can be used as a sensitive probe to quantify the donor strength of a thiolate ligand in a model system or protein, by simply measuring the Fe-NO and N-O frequencies of the ferric NO adduct and then projecting those data onto the correlation plot established here. Finally, we are able to show that the σ-trans effect of the thiolate is the electronic origin of the "push" effect, which is proposed to mediate O-O bond cleavage and Compound I formation in Cyt P450 monooxygenase catalysis.
