Effects of pH and chloride concentration on resonance Raman spectra of human myeloperoxidase and Raman microspectroscopic analysis of enzyme state in azurophilic granules

Araki, Koji; Takeuchi, Hideo

doi:10.1002/(sici)1097-0282(2000)57:3<169::aid-bip5>3.0.co;2-8

Cited by 6 publications

(1 citation statement)

References 49 publications

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“…40 A similar assignment has been recently reported for the bands in the high wavenumber region of Fe 3C MPO. 19 Based on their results these authors concluded that the distortion imposed by the covalent linkages lowers the symmetry of the heme in MPO from D 4h to C 2v . In the C 2v symmetry the A 1g and B 1g vibrational modes of D 4h symmetry belong to the totally symmetric A 1 species and the nontotally symmetric modes should correspond to one of the nontotally symmetric A 2 , B 1 , and B 2 species.…”

Section: Myeloperoxidasementioning

confidence: 99%

Resonance Raman assignment of myeloperoxidase and the selected mutants Asp94Val and Met243Thr. Effect of the heme distortion

Brogioni

Feis

Marzocchi

et al. 2006

J Raman Spectroscopy

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Resonance Raman (RR) spectra have been acquired for human myeloperoxidase (MPO), and its Met243Thrand Asp94Val mutants with different excitation wavelengths and in polarized light. The proteins were characterized as ferric, ferrous and ferric-CN complexes in order to study the heme configuration in various coordination, spin and oxidation states. Well-defined spectra of the five-coordinate high spin (ferrous), six-coordinate high spin (ferric) and low spin (ferric-CN) species were obtained. The data allowed us to propose an almost complete assignment of the RR bands. The richness of the RR spectra of MPO is because of the activation of almost all the in-plane skeletal modes observed for the Ni-octaethylporphyrin model compound, induced by the distortion of the heme imposed by the covalent links with the protein. The two mutants, which lost at least one of the covalent links between the protein and the heme group, were useful to determine the effect of the symmetry lowering of the heme group.

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Section: Myeloperoxidasementioning

confidence: 99%

Resonance Raman assignment of myeloperoxidase and the selected mutants Asp94Val and Met243Thr. Effect of the heme distortion

Brogioni

Feis

Marzocchi

et al. 2006

J Raman Spectroscopy

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Activation of lactoperoxidase by heme‐linked protonation and heme‐independent iodide binding

et al. 2009

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Lactoperoxidase (LPO), a mammalian secretory heme peroxidase, catalyzes the oxidation of thiocyanate by hydrogen peroxide to produce hypothiocyanate, an antibacterial agent. Although LPO is known to be activated at acidic pH and in the presence of iodide, the structural basis of the activation is not well understood. We have examined the effects of pH and iodide concentration on the catalytic activity and the structure of LPO. Electrochemical and colorimetric assays have shown that the catalytic activity is maximized at pH 4.5. The heme Soret absorption band exhibits a small red-shift at pH 5.0 upon acidification, which is ascribable to a structural transition from a neutral to an acidic form. Resonance Raman spectra suggest that the heme porphyrin core is slightly contracted and the Fe-His bond is strengthened in the acidic form compared to the neutral form. The structural change of LPO upon activation at acidic pH is similar to that observed for myeloperoxidase, another mammalian heme peroxidase, upon activation at neutral pH. Binding of iodide enhances the catalytic activity of LPO without affecting either the optimum pH of activity or the heme structure, implying that the iodide binding occurs at a protein site away from the heme-linked protonation site.

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Structure-biological activity relationships of myeloperoxidase to effect on platelet activation

Gorudko

Grigorieva

Shamova

et al. 2022

Archives of Biochemistry and Biophysics

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Effects of pH and chloride concentration on resonance Raman spectra of human myeloperoxidase and Raman microspectroscopic analysis of enzyme state in azurophilic granules

Cited by 6 publications

References 49 publications

Resonance Raman assignment of myeloperoxidase and the selected mutants Asp94Val and Met243Thr. Effect of the heme distortion

Resonance Raman assignment of myeloperoxidase and the selected mutants Asp94Val and Met243Thr. Effect of the heme distortion

Activation of lactoperoxidase by heme‐linked protonation and heme‐independent iodide binding

Structure-biological activity relationships of myeloperoxidase to effect on platelet activation

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