Resonance Raman spectra of methemoglobin derivatives. Selective enhancement of axial ligand vibrations and lack of an effect of inositol hexaphosphate

Asher, Sanford A.; Vickery, Larry E.; Schuster, Todd M.; Sauer, Kenneth

doi:10.1021/bi00645a032

Cited by 87 publications

(95 citation statements)

References 40 publications

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“…Attempts to gather direct evidence identifying the sixth ligand in ferric wt and Y171F DevS were unsuccessful. Specifically, low-frequency RR spectra in 18 OH 2 and D 2 O did not reveal isotope-sensitive modes that could be assigned to a ν(Fe-OH) mode, as previously observed with hydroxy-complexes in heme oxygenases and hemoglobin at high pH (18–21), nor a ν(Fe-O Tyr ) as previously observed in the 6cLS alkaline ferric Chlamydomonas hemoglobin (22) (Fig. S5).…”

Section: Resultssupporting

confidence: 73%

A Distal Tyrosine Residue Is Required for Ligand Discrimination in DevS from Mycobacterium tuberculosis

et al. 2008

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DevS is a heme-based sensor kinase required for sensing environmental conditions leading to non-replicating persistence in M. tuberculosis. Kinase activity is observed when the heme is ferrous 5-coordinate high-spin or 6-coordinate low-spin CO or NO complex, but is strongly inhibited in the oxy complex. Discrimination between these exogenous ligands has been proposed to depend on a specific hydrogen bond network with bound oxygen. Here we report resonance Raman data and autophosphorylation assays of wild-type and Y171F DevS in various heme complexes. The Y171F mutation eliminates ligand discrimination for CO, NO and O2, resulting in equally inactive complexes. In contrast, the ferrous-deoxy Y171F variant exhibits equivalent autokinase activity as the wild-type. Raman spectra of the oxy complex of Y171F indicate that the environment of the oxy group is significantly altered from that in the wild-type. They also suggest that a solvent molecule in the distal pocket substitutes for the Tyr hydroxyl group to act as a poorer hydrogen bond donor to the oxy group. The wild-type CO and NO complexes exist as a major population in which the CO or NO groups are free of hydrogen bonds while the Y171F mutation results in a mild increase in the distal pocket polarity. The Y171F mutation has no impact on the proximal environment of the heme, and the activity observed with the 5-coordinate ferrous-deoxy wild-type is conserved in the Y171F variant. Thus, while the absence of an exogenous ligand in the ferrous-deoxy proteins leads to a moderate kinase activity, interactions between Tyr171 and distal diatomic ligands turn the kinase activity ON and OFF. The Y171F mutation disrupts the ON/OFF switch and renders all states with a distal ligand inactive. This mechanistic model is consistent with Tyr171 being required for distal ligand discrimination, but non-essential for autophosphorylation activity.

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Section: Resultssupporting

confidence: 73%

A Distal Tyrosine Residue Is Required for Ligand Discrimination in DevS from Mycobacterium tuberculosis

et al. 2008

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“…The component dominated by the fluorescent background was important only for fitting purposes, so the two other components were named as component 1 (hemoglobindominated) and component 2 (fibrin-dominated). Component 1 was assigned to hemoglobin and its derivatives due to the presence of peaks at 1000, 1368, 1542 and 1620 cm -1 (Figure 1.B) [41][42][43]. The appearance of a hemoglobin-dominated principal component was expected.…”

Section: Raman Spectroscopic Signature Of Bloodmentioning

confidence: 98%

Discriminant Analysis of Raman Spectra for Body Fluid Identification for Forensic Purposes

Sikirzhytski

Virkler

Lednev

et al. 2010

AIP Conference Proceedings

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Detection and identification of blood, semen and saliva stains, the most common body fluids encountered at a crime scene, are very important aspects of forensic science today. This study targets the development of a nondestructive, confirmatory method for body fluid identification based on Raman spectroscopy coupled with advanced statistical analysis. Dry traces of blood, semen and saliva obtained from multiple donors were probed using a confocal Raman microscope with a 785-nm excitation wavelength under controlled laboratory conditions. Results demonstrated the capability of Raman spectroscopy to identify an unknown substance to be semen, blood or saliva with high confidence.

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“…The component dominated by the fluorescent background was important only for fitting purposes, so the two other components were named as component 1 (hemoglobin-dominated) and component 2 (fibrin-dominated). Component 1 was assigned to hemoglobin and its derivatives due to the presence of peaks at 1000, 1368, 1542 and 1620 cm −1 (Figure 1.B) [41–43]. The appearance of a hemoglobin-dominated principal component was expected.…”

Section: Multi-dimensional Raman Spectroscopic Signature For a Singlementioning

confidence: 99%

Discriminant Analysis of Raman Spectra for Body Fluid Identification for Forensic Purposes

Sikirzhytski

Virkler

Lednev

2010

Sensors

118

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Resonance Raman spectra of methemoglobin derivatives. Selective enhancement of axial ligand vibrations and lack of an effect of inositol hexaphosphate

Cited by 87 publications

References 40 publications

A Distal Tyrosine Residue Is Required for Ligand Discrimination in DevS from Mycobacterium tuberculosis

A Distal Tyrosine Residue Is Required for Ligand Discrimination in DevS from Mycobacterium tuberculosis

Discriminant Analysis of Raman Spectra for Body Fluid Identification for Forensic Purposes

Discriminant Analysis of Raman Spectra for Body Fluid Identification for Forensic Purposes

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