The Kinetics of Ligand Binding to Hemoglobin Valency Hybrids and the Effect of Anions

Cassoly, Robert; Gibson, Quentin H.

doi:10.1016/s0021-9258(19)44634-6

Cited by 84 publications

(32 citation statements)

References 25 publications

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“…This implied significant dissociation of ferro hybrids into dimers. This is not supported by the kinetic data obtained in the present study as well as in studies described by Cassoly and Gibson (1972) and the NMR data of Ogawa and Shulman (1971). From the tetramer-dimer dissociation equilibrium constant (1 X "6 M) one can calculate the concentrations of aC0/3+H20 prior to reduction with dithionite.…”

Section: Data Treatmentcontrasting

confidence: 97%

“…This is contrary to the generally held view f This work was supported by Grant HL 31159 from the National Institutes of Health. 0006-2960/90/0429-10106$02.50/0 that the quaternary structural changes are fast. Contrary to the findings of Ogawa and Shulman (1971) and Cassoly and Gibson (1972), which suggest that the fast phase is tetrameric, the studies of Smith and Ackers (1985) indicate extensive dissociation into dimers of deoxy hybrids (a2+CN02deo*y and a2deoxy^2+CN). These researchers studies the rates of dissociation of deoxy hybrids into dimers by the haptoglobin method.…”

mentioning

confidence: 68%

“…In our earlier study we made two main mistakes: (a) The analysis of the data was carried out by assuming fc4 = 1 s™1 as suggested by the earlier studies of fully liganded Hb and valency hybrids (Smith & Ackers, 1985). The kinetic data do not support this (Cassoly & Gibson, 1972). (b) The zero-time amplitude of the slow phase (Av4s) at 10 µ was studied at 437.8 nm.…”

Section: Discussionmentioning

confidence: 94%

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Double-mixing kinetic studies of the reactions of methyl isocyanide and carbon monoxide with diliganded intermediates of hemoglobin: .alpha.2CO.beta.2 and .alpha.2.beta.2CO

Berjis¹,

Bandyopadhyay²,

Sharma³

1990

Biochemistry

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Kinetics of the reactions of CO and methyl isocyanide with two diliganded intermediates of hemoglobin, alpha 2CO beta 2 and alpha 2 beta 2CO, have been studied by double-mixing and microperoxidase methods. The valency hybrids were prepared by high-pressure liquid chromatography. The reaction time courses of ligand combination and dissociation with both of the ligands were biphasic, and in CO combination reaction the zero-time amplitudes of the two phases were independent of the protein concentration. In the presence of 2 M urea the reaction time course was clearly dependent on protein concentration, as the zero-time amplitude of the fast phase increased at lower protein concentrations. These two observations indicate that little dissociation of tetramers into dimers occurs in the absence of urea. Consistent with this, the kinetic data for the reactions of CO best fit a reaction model consisting of two tetrameric species not in rapid equilibrium with each other. Various considerations, however, suggest that the reaction model is more appropriately described as 2D in equilibrium R in equilibrium T. The reaction of triliganded species (Hb4(CO)2Me1) with methyl isocyanide was monophasic, and the reaction model suggested a fast T in equilibrium R structural change after the binding of the third ligand. Although the precise structural nature of the two species remains undefined, it is concluded that the biphasicity in the reactions of the two hybrids is characteristic of the diliganded species only and is independent of the nature of the ligand.

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Section: Data Treatmentcontrasting

confidence: 97%

mentioning

confidence: 68%

Section: Discussionmentioning

confidence: 94%

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Double-mixing kinetic studies of the reactions of methyl isocyanide and carbon monoxide with diliganded intermediates of hemoglobin: .alpha.2CO.beta.2 and .alpha.2.beta.2CO

Berjis¹,

Bandyopadhyay²,

Sharma³

1990

Biochemistry

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“…Many lines of evidence have been. accumulated indicating that a and B chains,• within human hemog_lobin, react differenily [1][2][3][4][5][6][7][8][9]. Most of the studies point out that B chains are more reactive than the .a chains [1,2 ,4,5].…”

Section: Introductionmentioning

confidence: 99%

Chain inequivalence in bovine methemoglobin. Progress report, December 1, 1979-November 30, 1980

Ilan¹,

Chevion²,

Czapski³

1980

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“…A successful refinement of this model requires further structural information on the pathway of heme-heme interaction and on the less stable transition states induced by the progressive saturation of the unliganded form. Much effort was concentrated on the description of these aspects of cooperativity by studying valency hybrids (Cassoly & Gibson, 1972; , metal hybrids (Ikeda-Saito & Yonetani, 1980), and natural mutants substituted at the interface between heterologous subunits (Greer, 1971;Andersen, 1975;Salhany et al, 1975).…”

mentioning

confidence: 99%

Coupling of tertiary and quaternary changes in human hemoglobin: a 1D and 2D-NMR study of hemoglobin Saint Mande (.beta.N102Y)

Craescu

Mispelter²,

Blouquit³

1990

Biochemistry

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Hemoglobin Saint Mandé (beta N102Y) is a low-affinity mutant with the substitution site situated in the quaternary-sensitive alpha 1 beta 2 interface. In adult hemoglobin the Asn102 beta contributes to the stability of the liganded (R) state, forming a hydrogen bond with Asp94 alpha. The quaternary and tertiary perturbations subsequent to the Tyr for Asn substitution in monocarboxylated hemoglobin Saint Mandé have been investigated by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Analysis of the one-dimensional NMR spectra of the liganded and unliganded samples in 1H2O provides evidence that both R and T quaternary structures of Hb Saint Mandé are different from the corresponding ones in HbA. In the monocarboxylated form of the mutant hemoglobin, at acid pH, we have observed the disappearance of an R-type hydrogen bond and the appearance of a new one whose proton resonates like a deoxy T marker. Using two-dimensional NMR methods and on the basis of previous results on the monocarboxylated HbA, we have obtained a significant number of resonance assignments in the spectra of monocarboxylated Hb Saint Mandé at pH 5.6 in the presence or absence of a strong allosteric effector, inositol hexaphosphate. This enabled us to characterize the tertiary conformational changes (relative to the liganded normal hemoglobin) triggered by the quaternary-state modification. The observed structural variations are confined within the heme pocket regions but concern both the alpha and beta subunits. Most of them, localized in the C, F, G, and FG segments, could result directly from the side-chain substitution, while others, such as Leu141 beta, could be explained only by long-range interactions.

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The Kinetics of Ligand Binding to Hemoglobin Valency Hybrids and the Effect of Anions

Cited by 84 publications

References 25 publications

Double-mixing kinetic studies of the reactions of methyl isocyanide and carbon monoxide with diliganded intermediates of hemoglobin: .alpha.2CO.beta.2 and .alpha.2.beta.2CO

Double-mixing kinetic studies of the reactions of methyl isocyanide and carbon monoxide with diliganded intermediates of hemoglobin: .alpha.2CO.beta.2 and .alpha.2.beta.2CO

Chain inequivalence in bovine methemoglobin. Progress report, December 1, 1979-November 30, 1980

Coupling of tertiary and quaternary changes in human hemoglobin: a 1D and 2D-NMR study of hemoglobin Saint Mande (.beta.N102Y)

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