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PubMed · 7104456

Temperature-dependent conformation change in spin-labeled hemoglobin.

V Nöthig-Laslo·S Maricić
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Abstract

Hemoglobin was spin labeled at beta-93(F9)-cysteine with N-oxyl-2,2,6,6-tetramethylpiperidinylmaleimide. The inward shift of the high-field hyperfine line (delta Hx) position in the ESR spectra of the spin label was measured as a function of temperature. One can except that an abrupt change in the microenvironment around the tightly bound spin label will be reflected in the function delta Hx(T) as a discontinuity (break point). This was shown for aquo-, azido-, nitro- and oxyhemoglobin derivatives. The presented results suggest that the microenvironment around the tightly bound spin label in those methemoglobin derivatives that exhibit the mixed-spin state of the heme iron is prone to an abrupt change above a certain ligand-specific temperature. The change in microenvironment of the spin label is probably due to a temperature-dependent change in the teritary structure of the protein.

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HemoglobinsHumansHydrogen-Ion ConcentrationMethemoglobinProtein ConformationSpin LabelsTemperatureJournal ArticleResearch Support, Non-U.S. Gov't

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BibTeXRIS

V Nöthig-Laslo, S Maricić. 1982. Temperature-dependent conformation change in spin-labeled hemoglobin.. https://doi.org/10.1016/0301-4622(82)80005-7

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