Self‐association of hemoglobin: A dielectric dispersion study

Desnica, D.

doi:10.1002/bip.1979.360180708

Cited by 10 publications

(4 citation statements)

References 24 publications

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“…Firstly, the inclusions of physiological solution are not spheres; in fact, if a suitable shape factor of about 1.75 is used in equation (3), very good agreement can be obtained (figure 3). Secondly, it must be noted that, as pointed out by Desnica (1979), at this high haemoglobin concentration the intermolecular interactions become significant and therefore the dielectric constant as a function of the protein content may deviate from a straight line. Consequently, the observed discrepancy may be an artefact due to the extrapolation of the dielectric constant to high haemoglobin concentrations.…”

Section: And * + 2 and 7 -P And T + 2 Andmentioning

confidence: 94%

Microwave dielectric properties of normal and homozygous beta-thalassemic erythrocytes

et al. 1983

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Section: And * + 2 and 7 -P And T + 2 Andmentioning

confidence: 94%

Microwave dielectric properties of normal and homozygous beta-thalassemic erythrocytes

et al. 1983

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“…GI. (12) das Verhalten von tHb hinreichend gut beschreiben kann. Hierzu mufi tklb in Abhangigkeit von FKDI (co) bzw.…”

Section: Auswertung Der Absorptionsmessungenunclassified

Quantitative analyse der selbstassoziation von hämoglobinmolekülen anhand der konzentrationsabhängigkeit der spektren

Burkhard

Barnikol

1982

Makromol. Chem.

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The dependence of the spectrum of oxygenated hemoglobin (Hb) on the Hb concentration was measured and it was found that Hb solutions do not obey Lambert-Beer's law. The absorption coefficient depends clearly on the Hb concentration. As all external parameters were kept constant except Hb concentration, the only way to explain our result is to assume that Hb molecules undergo self association and that this self association is reflected in the behaviour of the absorption coefficient. To get parameters which are suited to describe the self association of Hb molecules, two models were used. The first model is based on the idea that Hb associates according to the following equation: Hb + Hb P (Hb),. Hb represents a single Hb molecule (consisting of two a-and two 8-chains) and (Hb), a complex of two Hb molecules. The second, more complicated model, takes into account higher associates of Hb molecules (like (Hb),, (Hb),, . . .). By using a least square fitting, it was possible to match experimental data and theoretical curves. Furthermore it became evident that at Hb concentrations, which are of physiological relevance, about 90% of the Hb molecules are involved in self association. The second model revealed that at those Hb concentrations there is a considerable portion of complexes which are composed of 10 or more Hb molecules.

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“…[1][2][3][4][5][6][7] Several theoretical models have been proposed to relate the experimental findings to the dielectric behavior of globular proteins in solution (ref 8 and references therein). [1][2][3][4][5][6][7] Several theoretical models have been proposed to relate the experimental findings to the dielectric behavior of globular proteins in solution (ref 8 and references therein).…”

Section: Introductionmentioning

confidence: 99%

“…The protein solutions' dielectric relaxation studies carried out during the last fifty years have provided important information about the potential relaxation mechanisms. − Several theoretical models have been proposed to relate the experimental findings to the dielectric behavior of globular proteins in solution (ref and references therein). The dielectric decrement ( I = ε 0 − ε ∞ / g ) and the relaxation time of native BSA were found to increase on the addition of a high concentration of urea up to 8 M, although the dielectric properties of the denatured state were not drastically different from those of the native protein (thus indicating that urea-denatured BSA still maintains considerable amounts of the original folding of peptide chains).…”

Section: Introductionmentioning

confidence: 99%

Study of the Denaturation Process in Albumin−Urea Solutions by Means of the Thermally Stimulated Depolarization Currents Technique

Vassilikou‐Dova¹,

Grigorakakis²,

Varotsos³

et al. 1996

J. Phys. Chem.

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The dielectric relaxation of bovine serum albumin (BSA) aqueous solution was studied in various stages of urea denaturation by means of the thermally stimulated depolarization currents (TSDC) technique. A large variation of urea concentration was utilized (0-4 M). Special attention was given for concentrations between 0.006 and 0.050 M, which are comparable to those measured in normal and uremic human serum. The TSDC spectrum consists of two main bands in the temperature range 100-300 K: (1) a broad low-temperature band (A) with two maxima at about 128 and 142 K, which are attributed to the (re)orientation mechanisms of bulk and hydration water molecules, respectively, and (2) an intense band (B), whose position varies in the range between 230 and 245 K and which is attributed to the (re)orientation of protein macromolecules. Two peaks of lower intensity (B 1 and B 2 ) are resolved in the rising part of band B and are most likely due to relaxation mechanisms of the side chains of BSA. The activation energies for the last three mechanisms depend on urea concentration, and this fact might be attributed to the conformational changes of BSA upon denaturation. It is of interest to note that the macromolecules' activation energies depend drastically on the concentration of urea up to 0.05 M. Abstract published in AdVance ACS Abstracts, December 15, 1995.

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Self‐association of hemoglobin: A dielectric dispersion study

Cited by 10 publications

References 24 publications

Microwave dielectric properties of normal and homozygous beta-thalassemic erythrocytes

Microwave dielectric properties of normal and homozygous beta-thalassemic erythrocytes

Quantitative analyse der selbstassoziation von hämoglobinmolekülen anhand der konzentrationsabhängigkeit der spektren

Study of the Denaturation Process in Albumin−Urea Solutions by Means of the Thermally Stimulated Depolarization Currents Technique

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