Lack of orientation selectivity of the heme insertion in murine neuroglobin revealed by resonance Raman spectroscopy

Milazzo, Lisa; Exertier, Cécile; Becucci, Maurizio; Freda, Ida; Montemiglio, Linda Celeste; Savino, C.; Vallone, B.; Smulevich, Giulietta

doi:10.1111/febs.15241

Cited by 13 publications

(38 citation statements)

References 47 publications

(268 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The vinyl stretching modes [ν(C=C), in blue] at 1,620 and 1,630 cm −1 (Figures 4C,D) are identical for all the spectra. The frequencies are sensitive to their orientations with respect to the porphyrin plane (Marzocchi and Smulevich, 2003), indicating trans and cis configurations, respectively (Milazzo et al, 2020). , and their mutants.…”

Section: Heme Environment In Wild-type and Mutated Globinsmentioning

confidence: 99%

A Plant Gene Encoding One-Heme and Two-Heme Hemoglobins With Extreme Reactivities Toward Diatomic Gases and Nitrite

et al. 2020

Self Cite

View full text Add to dashboard Cite

In plants, symbiotic hemoglobins act as carriers and buffers of O 2 in nodules, whereas nonsymbiotic hemoglobins or phytoglobins (Glbs) are ubiquitous in tissues and may perform multiple, but still poorly defined, functions related to O 2 and/or nitric oxide (NO). Here, we have identified a Glb gene of the model legume Medicago truncatula with unique properties. The gene, designated MtGlb1-2, generates four alternative splice forms encoding Glbs with one or two heme domains and 215-351 amino acid residues. This is more than double the size of any hemoglobin from plants or other organisms described so far. A combination of molecular, cellular, biochemical, and biophysical methods was used to characterize these novel proteins. RNA-sequencing showed that the four splice variants are expressed in plant tissues. MtGlb1-2 is transcriptionally activated by hypoxia and its expression is further enhanced by an NO source. The gene is preferentially expressed in the meristems and vascular bundles of roots and nodules. Two of the proteins, bearing one or two hemes, were characterized using mutants in the distal histidines of the hemes. The Glbs are extremely reactive toward the physiological ligands O 2 , NO, and nitrite. They show very high O 2 affinities, NO dioxygenase activity (in the presence of O 2), and nitrite reductase (NiR) activity (in the absence of O 2) compared with the hemoglobins from vertebrates and other plants. We propose that these Glbs act as either NO scavengers or NO producers depending on the O 2 tension in the plant tissue, being involved in the fast and fine tuning of NO concentration in the cytosol in response to sudden changes in O 2 availability.

show abstract

Section: Heme Environment In Wild-type and Mutated Globinsmentioning

confidence: 99%

A Plant Gene Encoding One-Heme and Two-Heme Hemoglobins With Extreme Reactivities Toward Diatomic Gases and Nitrite

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Comparison of the experimental conditions is reported in Table 3. From Milazzo et al [43] [Colour figure can be viewed at wileyonlinelibrary.com] Note: From Milazzo et al [43] protein displaying both the canonical and reversed heme orientations. Interestingly, The X-ray data showed that the two conformers are structurally different.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, the combination of RR spectroscopy on single crystal and solution samples has proved to be a sensitive diagnostic tool that could be extended to other heme proteins to detect heme F I G U R E 1 0 Low wavenumber region resonance Raman (RR) spectra of ferric murine Ngb WT (bottom) and the Gly-loop [44][45][46][47] /F106A mutant (top), in solution, taken with a 413.1 nm excitation. Adapted from Milazzo et al [43] [Colour figure can be viewed at wileyonlinelibrary.com]…”

Section: Discussionmentioning

confidence: 99%

“…New insights for the identification of rotational heme disorder in heme proteins have been provided recently by the combination of solution RR spectroscopy using polarized light different excitation wavelengths, and single crystal micro-RR spectroscopy, together with crystal structures of murine wild-type (WT) Ngb and selected variants. [5,43] The structural heterogeneity of WT murine Ngb has been clearly detected by the solution 1 H-NMR spectrum [35] and in the 1.5 Å-resolution X-ray structure [4] of the ferric form (Figure 7). Two different 6-coordinated low spin conformers mutually rotated by 180 about the α,γ-meso axis have been identified, where the reversed insertion represents the main conformer with about 70% occupancy.…”

Section: Rr Of the Reversed Conformationmentioning

confidence: 99%

See 1 more Smart Citation

Detecting rotational disorder in heme proteins: A comparison between resonance Raman spectroscopy, nuclear magnetic resonance, and circular dichroism

Sebastiani

Milazzo

Exertier

et al. 2021

J Raman Spectroscopy

Self Cite

View full text Add to dashboard Cite

In heme proteins, the canonical and reversed conformations result from the rotation of the heme group by 180 about the α,γ-meso axis in the protein pocket. The coexistence of the two different heme orientations has been observed both in proteins reconstituted with hemin and in some native proteins. The reversal of the heme orientation can also change certain functional properties of heme proteins. Complementing the results from other experimental techniques, like circular dichroism and nuclear magnetic resonance, resonance Raman spectroscopy provides detailed information on the structure of the reversed heme. This allows one to elucidate the effects of the heme rotation on the vibrational spectra of the peripheral substituents, especially the vinyl groups. Furthermore, the combination of resonance Raman spectroscopy on single crystals and solution samples of heme proteins is proposed to be a sensitive tool to detect heme orientational disorder, even in the absence of structural data.

show abstract

“…The band at around 1,614 cm −1 contains contributions from the two vinyl side chains of hemin that converge at the same wavenumber value due to the coplanar orientation of both groups with the porphyrin plane (Milazzo et al, 2020). On SERS substrates (see Figure 6A), the wavenumber value of the 1,614 cm −1 band undergoes a gradual down-shift when glyphosate concentration is increased in the hemin solution, reaching a value of 1,609 cm −1 at the highest tested concentration (1×10 −5 M).…”

Section: Origin Of the Sers Effectmentioning

confidence: 99%

Indirect Quantification of Glyphosate by SERS Using an Incubation Process With Hemin as the Reporter Molecule: A Contribution to Signal Amplification Mechanism

et al. 2020

View full text Add to dashboard Cite

The indirect determination of the most used herbicide worldwide, glyphosate, was achieved by the SERS technique using hemin chloride as the reporter molecule. An incubation process between hemin and glyphosate solutions was required to obtain a reproducible Raman signal on SERS substrates consisting of silicon decorated with Ag nanoparticles (Si-AgNPs). At 780 nm of excitation wavelength, SERS spectra from hemin solutions do not show extra bands in the presence of glyphosate. However, the hemin bands increase in intensity as a function of glyphosate concentration. This allows the quantification of the herbicide using as marker band the signal associated with the ring breathing mode of pyridine at 745 cm−1. The linear range was from 1 × 10−10 to 1 × 10−5 M and the limit of detection (LOD) was 9.59 × 10−12 M. This methodology was successfully applied to the quantification of the herbicide in honey. From Raman experiments with and without silver nanoparticles, it was possible to state that the hemin is the species responsible for the absorption in the absence or the presence of the herbicide via vinyl groups. Likewise, when the glyphosate concentration increases, a subtle increase occurs in the planar orientation of the vinyl group at position 2 in the porphyrin ring of hemin over the silver surface, favoring the reduction of the molecule. The total Raman signal of the hemin-glyphosate incubated solutions includes a maximized electromagnetic contribution by the use of the appropriate laser excitation, and chemical contributions related to charge transfer between silver and hemin, and from resonance properties of Raman scattering of hemin. Incubation of the reporter molecule with the analyte before the conjugation with the SERS substrate has not been explored before and could be extrapolated to other reporter-analyte systems that depend on a binding equilibrium process.

show abstract

Lack of orientation selectivity of the heme insertion in murine neuroglobin revealed by resonance Raman spectroscopy

Cited by 13 publications

References 47 publications

A Plant Gene Encoding One-Heme and Two-Heme Hemoglobins With Extreme Reactivities Toward Diatomic Gases and Nitrite

A Plant Gene Encoding One-Heme and Two-Heme Hemoglobins With Extreme Reactivities Toward Diatomic Gases and Nitrite

Detecting rotational disorder in heme proteins: A comparison between resonance Raman spectroscopy, nuclear magnetic resonance, and circular dichroism

Indirect Quantification of Glyphosate by SERS Using an Incubation Process With Hemin as the Reporter Molecule: A Contribution to Signal Amplification Mechanism

Contact Info

Product

Resources

About