Evidence of hemoglobin dissociation.
Bovine carbonmonoxy hemoglobin investigated with light scattering studies is found to dissociate from its native tetramer structure into dimers and monomers. The values of the hydrated tetramer radius, RT = 32.1 A, and the fractional dissociation vs pH, have been obtained at different ionic strengths from the autocorrelation function of the scattered light. The results suggest that a relevant contribution to Hb dissociation is due to electrostatic effects and, by means of a model derived by Tanford, it has been possible to predict the behavior of dissociation. Among the findings of this approach, we recall the estimates of the electrostatic energy contributions to Hb dissociation, up to congruent to 6RT, and the predicted charge of tetrameric Hb vs pH, which agrees very well with the experimental data.
Dipartimento di Fiscia, Università degli Studi, Milano, Italy.
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L
Lunelli
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P
Zuliani
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G
Baldini
D000818:Animals; D002263:Carboxyhemoglobin / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism*; D008027:Light; D046911:Macromolecular Substances; D012542:Scattering, Radiation
D006454:Hemoglobins; D046911:Macromolecular Substances; D002263:Carboxyhemoglobin