Carbon-13 magnetic resonance studies of the binding of carbon monoxide to various hemoglobins

Moon, Richard B.; Richards, John H.

doi:10.1021/bi00714a003

Cited by 67 publications

(33 citation statements)

References 33 publications

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“…As in the case of human and rabbit hemoglobins [3] a difference in the affinity for carbon monoxide between the two chains is clearly evident. It is suggestive that the chain which experiences the more marked pH shift is the one with lower ligand affintiy.…”

Section: Resultsmentioning

confidence: 75%

“…This comparison indicates that the immediate interactions of CO with nearby protein residues are not significantly modified by pH even for those hemoglobins which display a Bohr effect (like human ISA) [3]. On the other hand in I-lb trout IV, proton dependent structural changes may involve some of the residues in the vicinity of the ligand in the heme pocket.…”

Section: Resultsmentioning

confidence: 86%

“…1), strictly pH independent over the range from 6 to 8. As in the case of pigeon I-lb [3] the interactions between the ligand and the neighbouring groups must be very similar for the two different polypeptide chains.…”

Section: Resultsmentioning

confidence: 98%

“…The chemical shifts were transformed to p.p.m. from TMS using the value of 184.60 for the free CO [3] .…”

Section: Methodsmentioning

confidence: 99%

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Observations on CO trout hemoglobins by ¹³C NMR

Giacometti¹,

Giardina²,

Brunori³

et al. 1976

FEBS Letters

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Section: Resultsmentioning

confidence: 75%

Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 98%

“…The chemical shifts were transformed to p.p.m. from TMS using the value of 184.60 for the free CO [3] .…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Observations on CO trout hemoglobins by ¹³C NMR

Giacometti¹,

Giardina²,

Brunori³

et al. 1976

FEBS Letters

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“…Yet substitutioii near these sites may cause changes in the ligand affinities. An example for such an effect is the low ligand affinities of rabbit hemoglobin I chains [24,25]. It is postulated that the low affinity of rabbit E chains is due to the substitution at the a48 (CD 6) Leu-Phe and a49 (CD 7) Ser-Thr, involving size differences [24,25].…”

Section: Discussionmentioning

confidence: 99%

Structural, Functional and Conformational Properties of Rat Hemoglobins

John

1982

European Journal of Biochemistry

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The oxygen equilibrium properties of rat total hemoglobin show pH dependence. Thus oxygen affinity and cooperativity, which are significantly reduced at pH 6.0, show increase with increasing pH. Conformational studies using nitrosyl derivatives indicate that in rat nitrosyl hemoglobin the R to T equilibrium is shiftcd towards the T state in going from pH 7.0 to pH 6.0. Under similar conditions human hemoglobin A shows no significant changes in cooperativity or conformation. These results indicate that a destabilized oxy structure (R) exist in rat hemoglobins at pH 6.0. Alterations in the heme pockets and a1 p2 contact points could Icad to these structural characteristics. Crystallization of rat hemoglobins is dependent on an oxy-like structure since all liganded ferrous derivatives and methemoglobin form crystals in the pH range of 7.0-8.0. Deoxygenation of oxyhemoglobin crystals or addition of inositol hexakisphosphate to nitrosyl or methemoglobin derivatives result in the solubilization of the crystals. Thus the quaternary and/or tertiary structural changes involved in the transition of an R to T state disrupt the crystal structure. The precise positioning of the complementary sites involved in the interaction of amino acids between rat hemoglobin tetramers seems to occur only when the molecules are in the quaternary or tertiary R conformation. This is in contrast to the polymerization 01' human deoxyhemoglobin S, where gel formation occurs only in the T state.

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13C- and57Fe-NMR studies of the FeCO unit of heme proteins and synthetic model compounds in solution: Comparison with IR vibrational frequencies and X-ray structural data

1998

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13C‐ and 57Fe‐NMR spectra of several carbon monoxide hemoprotein models with varying polar and steric effects of the distal organic superstructure, constraints of the proximal side, and solvent polarity are reported. The 13C shieldings of heme models cover a 4.0 ppm range that is extended to 7.0 ppm when several hemoglobin CO and myoglobin CO species at different pHs are included. Both heme models and heme proteins obey a similar excellent linear δ(13C) versus ν(CO) relationship that is primarily due to modulation of π backbonding from Fe dπ to the CO π* orbital by the distal pocket polar interactions. There is no direct correlation between δ(13C) and FeCO geometry. The poor monotonic relation between δ(13C) and ν(FeC) indicates that the iron‐carbon π bonding is not a primary factor influencing δ(13C) and δ(57Fe). The δ(57Fe) was found to be extremely sensitive to deformation of the porphyrin geometry, and increased shielding by more than 600 ppm with increased ruffling was observed for various heme models of known X‐ray structures. © 1998 John Wiley & Sons, Inc. Biospectroscopy 4: S57–S69, 1998

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Carbon-13 magnetic resonance studies of the binding of carbon monoxide to various hemoglobins

Cited by 67 publications

References 33 publications

Observations on CO trout hemoglobins by ¹³C NMR

Observations on CO trout hemoglobins by ¹³C NMR

Structural, Functional and Conformational Properties of Rat Hemoglobins

13C- and57Fe-NMR studies of the FeCO unit of heme proteins and synthetic model compounds in solution: Comparison with IR vibrational frequencies and X-ray structural data

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Carbon-13 magnetic resonance studies of the binding of carbon monoxide to various hemoglobins

Cited by 67 publications

References 33 publications

Observations on CO trout hemoglobins by 13C NMR

Observations on CO trout hemoglobins by 13C NMR

Structural, Functional and Conformational Properties of Rat Hemoglobins

13C- and57Fe-NMR studies of the FeCO unit of heme proteins and synthetic model compounds in solution: Comparison with IR vibrational frequencies and X-ray structural data

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Product

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Observations on CO trout hemoglobins by ¹³C NMR

Observations on CO trout hemoglobins by ¹³C NMR