Discrimination between Oxygen and Carbon Monoxide and Inhibition of Autooxidation by Myoglobin

Springer, Barry A.; Egeberg, Karen D.; Sligar, Stephen G.; Rohlfs, Ronald J.; Mathews, Antony J.; Olson, John S.

doi:10.1016/s0021-9258(18)94029-9

Cited by 283 publications

(155 citation statements)

References 29 publications

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“…Native sperm whale myoglobin was purchased from Sigma Chemical Company (St. Louis, MO) as lyophilized powder and used without further purification. Mutations at positions 64 and 97 were generated using sitedirected mutagenesis procedures described by Springer et al (1989). Oligonucleotides were synthesized by the University of Illinois Biotechnology Center and purified by reverse-phase high performance liquid chromatography (Springer and Sligar, 1987).…”

Section: Biochemical Proceduresmentioning

confidence: 99%

Connection between the Taxonomic Substates and Protonation of Histidines 64 and 97 in Carbonmonoxy Myoglobin

Müller

McMahon

Chien

et al. 1999

Biophysical Journal

107

132

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Infrared spectra of heme-bound CO in sperm whale carbonmonoxy myoglobin and two mutants (H64L and H97F) were studied in the pH range from 4.2 to 9.5. Comparison of the native protein with the mutants shows that the observed pH effects can be traced to protonations of two histidine residues, H64 and H97, near the active site. Their imidazole sidechains experience simple, uncoupled Henderson-Hasselbalch type protonations, giving rise to four different protonation states. Because two of the protonation states are linked by a pH-independent equilibrium, the overall pH dependence of the spectra is described by a linear combination of three independent components. Global analysis, based on singular value decomposition and matrix least-squares algorithms enabled us to extract the pK values of the two histidines and the three basis spectra of the protonating species. The basis spectra were decomposed into the taxonomic substates A(0), A(1), and A(3), previously introduced in a heuristic way to analyze CO stretch spectra in heme proteins at fixed pH (see for instance, Biophys. J. 71:1563-1573). Moreover, an additional, weakly populated substate, called A(x), was identified. Protonation of H97 gives rise to a blue shift of the individual infrared lines by about 2 cm(-1), so that the A substates actually appear in pairs, such as A(0) and A(0)(+). The blue shift can be explained by reduced backbonding from the heme iron to the CO. Protonation of the distal histidine, H64, leads to a change of the infrared absorption from the A(1) or A(3) substate lines to A(0). This behavior can be explained by a conformational change upon protonation that moves the imidazole sidechain of H64 away from the CO into the high-dielectric solvent environment, which avoids the energetically unfavorable situation of an uncompensated electric charge in the apolar, low-dielectric protein interior. Our results suggest that protonation reactions serve as an important mechanism to create taxonomic substates in proteins.

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Section: Biochemical Proceduresmentioning

confidence: 99%

Connection between the Taxonomic Substates and Protonation of Histidines 64 and 97 in Carbonmonoxy Myoglobin

Müller

McMahon

Chien

et al. 1999

Biophysical Journal

107

132

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“…It has been known for a long time that the Mb environment lowers the binding affinity of CO to the heme group compared to O 2 , whereas in solution CO binds to the free heme stronger than O 2 [65]. One possible explanation was based on different electrostatic interactions between the ligand and the distal site of the heme pocket [66], resulting in a stronger hydrogen bond between H64ϵ and O 2 compared to the CO ligand.…”

Section: Introductionmentioning

confidence: 99%

Critical assessment of the FeC and CO bond strength in carboxymyoglobin: a QM/MM local vibrational mode study

Freindorf

Kraka

2020

J Mol Model

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The interplay between FeC and CO bonding in carboxymyoglobin (MbCO) and the role of potential hydrogen bonding between the CO moiety and the side chains of the surrounding protein amino acids have been the subject of numerous experimental and theoretical studies. In this work, we present a quantitative measure for the intrinsic FeC and CO bond strength in MbCO, as well as for CO⋯H bonding, based on the local vibrational mode analysis, originally developed by Konkoli and Cremer. We investigated a gas phase model, two models of the wild-type protein, and 17 protein mutations that change the distal polarity of the heme pocket, as well as two protein mutations of the heme porphyrin ring. Based on local mode force constants, we could quantify for the first time the suggested inverse relationship between the CO and FeC bond strength, the strength of CO⋯H bonding, and how it weakens the CO bond. Combined with the natural orbital analysis, we could also confirm the key role of π back donation between Fe and the CO moiety in determining the FeC bond strength. We further clarified that CO and FeC normal modes couple with other protein motions in the protein environment. Therefore, normal mode frequencies/force constants are not suited as bond strength descriptors and instead their local mode counterparts should be used. Our comprehensive results provide new guidelines for the fine-tuning of existing and the design of MbCO models with specific FeC, CO, and CO⋯H bond strengths.

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“…This is while the experimental binding energy of NO in [MI-Fe II P-NO] complex has been reported to −22.8 kcal mol −1 by Olson 10 and Springer. 48 Nevertheless, the corresponding theoretical value has been reported to lie within the range of –(12.45–36.0) kcal mol −1 by different theoretical groups. 13,37,38,49,50 Thus, our theoretical result (−16.5 kcal mol −1 ) is in good agreement with experimental- and previous theoretical reports as well.…”

Section: Resultsmentioning

confidence: 94%

Insights into the effect of distal histidine and water hydrogen bonding on NO ligation to ferrous and ferric heme: a DFT study

2022

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Discrimination between Oxygen and Carbon Monoxide and Inhibition of Autooxidation by Myoglobin

Cited by 283 publications

References 29 publications

Connection between the Taxonomic Substates and Protonation of Histidines 64 and 97 in Carbonmonoxy Myoglobin

Connection between the Taxonomic Substates and Protonation of Histidines 64 and 97 in Carbonmonoxy Myoglobin

Critical assessment of the FeC and CO bond strength in carboxymyoglobin: a QM/MM local vibrational mode study

Insights into the effect of distal histidine and water hydrogen bonding on NO ligation to ferrous and ferric heme: a DFT study

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