Structural heterogeneity of the Fe(2+)-N epsilon (HisF8) bond in various hemoglobin and myoglobin derivatives probed by the Raman-active iron histidine stretching mode

Gilch, Harald; Schweitzer‐Stenner, Reinhard; Dreybrodt, Wolfgang

doi:10.1016/s0006-3495(93)81216-5

Cited by 34 publications

(49 citation statements)

References 63 publications

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“…The I max positions and the frequencies of the two components follow the progression rHbA < W37Y < W37A < W37G < W37E. It should be noted that the fits are approximations to the true band shape since each chain's ν(Fe-His) band is more complex than a simple Gaussian (Gilch et al, 1993), so the fits do not completely describe all the differences apparent in the spectra. It should also be noted that a peak shift of the ν(Fe-His) band can be achieved both by shifting the frequency of one or both of these two components and/or by changing the relative intensity of one with respect to the other.…”

Section: Resultsmentioning

confidence: 99%

A Possible Allosteric Communication Pathway Identified through a Resonance Raman Study of Four β37 Mutants of Human Hemoglobin A

Peterson

Friedman

1998

Biochemistry

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The highly conserved tryptophan at position beta37 occupies a key locus at the hinge region within the alpha1beta2 interface of the mammalian hemoglobins. This residue is thought to play an important role in mediating the heme-heme interaction associated with the cooperative binding of oxygen; however, its explicit function is unclear. In this study, the proximal heme environments of several beta37 mutants of adult human hemoglobin (HbA) are probed using visible (Soret band enhanced) resonance Raman spectroscopy. In the equilibrium deoxy derivatives of these mutants, a systematic variation in proximal strain, as reflected in the iron-proximal histidine (F8) stretching frequency, nu(Fe-His), is seen upon mutation of the beta37 residue. The variation in proximal strain correlates with both the ligand binding rates [Kwiatkowski et al. (1998) Biochemistry 37, 4325-4335] and conformational changes observed at the FG corner through X-ray crystallography [Kavanaugh et al. (1998) Biochemistry 37, 4358-4373]. The results from the deoxy samples indicate a plasticity of the tertiary structure within the T quaternary state. The correlation between the X-ray data and the Raman supports the idea that the proximal strain at the heme within the T state can be modulated by a combination of forces including those arising from the hinge region of the alpha1beta2 interface, from the binding of allosteric effectors, and from the degree of iron displacement from the heme plane. Each of these contributors appears to operate through a shifting of the F helix either away from or toward the FG corner. The Raman spectra obtained from the 10 ns CO photoproduct of the beta37 mutant Hb's indicate that these mutants contain an altered coupling between the R state alpha1beta2 interface and the proximal heme environment. This altered coupling could be due to either dissociation of the ligated mutant tetramers into dimers or the formation of an R state tetramer with significantly weakened hydrogen bonds and van der Waals contacts between the alpha1 and beta2 subunits at the interface. In either case, the results reveal a clear-cut structural basis for the quaternary enhancement effect in which the normal R state quaternary structure produces a higher affinity ligand binding site than that which occurs in the corresponding dimeric form of the protein. The normal R state interface is shown to be important for stabilizing a favorable ligand binding environment that persists long enough after laser photolysis to enhance the geminate rebinding process within the photoproduct. The addition of IHP to the solution of mutant COHb proteins results in photoproduct spectra that are all identical and are consistent with the ligand-bound derivatives having either a T state structure or a very strained and anomalous R state structure.

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Section: Resultsmentioning

confidence: 99%

A Possible Allosteric Communication Pathway Identified through a Resonance Raman Study of Four β37 Mutants of Human Hemoglobin A

Peterson

Friedman

1998

Biochemistry

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“…This increase is in agreement (although less pronounced) with the S365/8674 increase for cyanomet derivatives reported in Table 1. 5) A further possibility is that the $365 values reported in Table 1 are overestimated owing to the presence of Soret sub-bands arising from optically distinguishable conformers of the hemegroup with a peak frequency shift of the order of 350 cm -1 (Gilch et al 1993(Gilch et al , 1994. We therefore Table 1.…”

Section: Resultsmentioning

confidence: 99%

Low temperature optical spectroscopy of low-spin ferric hemeproteins

Leone¹,

Cupane²,

Cordone³

1996

Eur Biophys J

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We report the Soret absorption spectra (500-350 nm) of the cyanomet derivatives of human hemoglobin and horse myoglobin, in the temperature range 300-20 K and in two different solvents (65% v/v glycerol-water or 65% v/v ethylene glycol-water). In order to obtain information on stereodynamic properties of active site of the two hemeproteins, we perform an analysis of the band profiles within the framework of electron-vibrations coupling. This approach enables us to single out the various contributions to the spectral bandwidth, such as those arising from non-radiative decay of the excited electronic state (homogeneous broadening) and from the coupling of the electronic transition i) with high frequency modes (that determines the vibronic structure of the band) and ii) with a "bath" of low frequency modes (that is responsible for the temperature dependence of the experimental spectra). We discuss the relevant parameters and their temperature dependence and compare them with the ones already reported for other derivatives of the same hemeproteins in the same solvents. In particular, non-harmonic contributions to soft modes are found, for cyanomet derivatives, to be larger than those observed for liganded carbonmonoxy but smaller than those observed for unliganded deoxy derivatives. The reported data enable us to obtain information on the dependence of stereodynamic properties of the heme pocket upon iron oxidation state, dimensions of the exogenous ligand and composition of the external matrix.

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“…The resonance Raman band associated with the iron-histidine bond stretching mode (m Fe-His ) was first reported by Kitagawa et al for deoxy myoglobin [67]. It was later recognized that this mode is only observable in the five-coordinate deoxy derivative, and is very sensitive to the protein matrix surrounding the histidine [52,60,[68][69][70][71]. In monomeric sperm whale myoglobin (Mb), the frequency of m Fe-His is 220 cm À1 .…”

Section: The Proximal Iron-histidine Stretching Modementioning

confidence: 99%

Structural and functional properties of hemoglobins from unicellular organisms as revealed by resonance Raman spectroscopy

Egawa

Yeh

2005

Journal of Inorganic Biochemistry

159

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Structural heterogeneity of the Fe(2+)-N epsilon (HisF8) bond in various hemoglobin and myoglobin derivatives probed by the Raman-active iron histidine stretching mode

Cited by 34 publications

References 63 publications

A Possible Allosteric Communication Pathway Identified through a Resonance Raman Study of Four β37 Mutants of Human Hemoglobin A

A Possible Allosteric Communication Pathway Identified through a Resonance Raman Study of Four β37 Mutants of Human Hemoglobin A

Low temperature optical spectroscopy of low-spin ferric hemeproteins

Structural and functional properties of hemoglobins from unicellular organisms as revealed by resonance Raman spectroscopy

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