Oxyhemoglobin resonances

Labrude, P., Rasolomana, M. Atomization of oxyhemoglobin in the presence of sucrose. Study by circular dichroism and electronic paramagnetic resonance, comparison with freezedrying. S. T. P. Pharma 4 (6), p. 472 80, 1988... 

Kosaka, H., Imaizumi, K., and Tyuma, 1. (1981). Mechanism of autocatalytic oxidation of oxyhemoglobin by nitrite an intermediate detected by electron spin resonance. Biochim. Biophys. Acta 702, 237-241. 

Zimmer J, Van Wart HE (1982) Resonance Raman spectrum of horseradish peroxidase compound III comparison with oxyhemoglobin. Biochem Biophys Res Commun 108 977-981... 

Since the pioneering work by Cotton et al. on heme proteins (Cotton et al., 1980), surface enhanced resonance Raman spectroscopy (SERRS), Sec. 6.1, has been used to study a large variety of biomolecules, such as retinal proteins (Nabiev et al., 1985), flavoproteins (Coperland et al., 1984 Holt and Cotton, 1987), chlorophylls (Cotton and Van Duyne, 1982 Hildebrandt and Spiro, 1988), and oxyhemoglobins (de Groot and Hesters, 1987). The advantages of this technique include low sample concentration and fluorescence quenching. The main question is whether or not the native structure and function of the molecule is preserved on the metal surface. 

P. Smith and K. R. Maples, Oxidation of phenylhydrazine initiated by the titanous chloride/hydrogen peroxide reaction and by oxyhemoglobin, J. Magn. Reson., 65 (1985) 491-496. 

B2y, and >42 vibrations are expected to be polarized (p), depolarized (dp), and inversely polarized (tp ), respectively. These polarization properties, together with their vibrational frequencies, were used by Spiro and his coworkers to make complete assignments of vibrational spectra of the Fe-porphin skeletons of a series of heme proteins. They showed that the resonance Raman spectrum may be used to predict the oxidation and spin states of the Fe atom in heme proteins. For example, the Fe atom in oxyhemoglobin has been shown to be low-spin Fc(IIl). It should be noted that the A2y mode, which is normally Raman inactive, is observed under the resonance condition. Although the modes are rather weak in Fig. I-19, these vibrations are enhanced markedly and exclusively by the excitation near the B band since the A-term resonance is predominant under such condition. The majority of compounds studied thus far exhibit the A-term rather than the l -term resonance. A more complete study of resonance Raman spectra involves the observation of excitation profiles (Raman intensity plotted as a function of the exciting frequency for each mode), and the simulation of observed excitation proliles based on various theories of resonance Raman spectroscopy. ... 

Two electron transfers from cytochrome c substrate convert the inactive oxidized enzyme with Fe -Cu bimetallic site to an active Fe -Cu state mixed-valent form. The first intermediate in the reaction of O2 is an adduct with cytochrome 3, an Fe-02 moiety with i/p -o = 572cm (from resonance Raman (rR) spectroscopy) closely resembling those observed in oxyhemoglobin. It appears to involve a Fe<23 -02 in an end-on configuration, without any significant interaction with the Cu center, consistent with the crystallographic data. The subsequent reaction was... 

Fig. 11. Resonance Raman spectra of (a) ferrocytochrome c, 0.5 mM obtained with S14.5 nm excitation and (b) oxyhemoglobin, 0.5 mM, obtained with 568.2 nm excitation. From [7b].

Of the structures of oxyhemoglobin compatible with the magnetic data, the most probable is the resonating structure analogous to that of carbon-monoxyhemoglobin ... 

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