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Mikael Esmann

Analysis of thiol-topography in Na,K-ATPase using labelling with different maleimide nitroxide derivatives

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Analysis of thiol-topography in Na,K-ATPase using labelling with different maleimide nitroxide derivatives. / Esmann, Mikael; Hideg, K; Marsh, D.

I: BBA General Subjects, Bind 1112, Nr. 2, 09.12.1992, s. 215-225.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

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Esmann, M, Hideg, K & Marsh, D 1992, 'Analysis of thiol-topography in Na,K-ATPase using labelling with different maleimide nitroxide derivatives', BBA General Subjects, bind 1112, nr. 2, s. 215-225.

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Author

Esmann, Mikael ; Hideg, K ; Marsh, D. / Analysis of thiol-topography in Na,K-ATPase using labelling with different maleimide nitroxide derivatives. I: BBA General Subjects. 1992 ; Bind 1112, Nr. 2. s. 215-225.

Bibtex

@article{4382b32375e84bdca9032bbaf4851721,
title = "Analysis of thiol-topography in Na,K-ATPase using labelling with different maleimide nitroxide derivatives",
abstract = "Spin-label EPR spectroscopy of shark rectal gland Na,K-ATPase modified at cysteine residues with a variety of maleimide-nitroxide derivatives is used to characterize the different classes of sulphydryl groups. The spin-labelled derivatives vary with respect to charge and lipophilicity, and the chemical reactivity towards modification and inactivation of the Na,K-ATPase is dependent on these properties. Ascorbate is used to reduce the spin-labels in situ, and the kinetics of reduction of the protein-bound spin-labels are found also to depend on the nature of the maleimide-nitroxide derivative. The Na,K-ATPase is labelled either at Class I groups (with retention of enzymatic activity) or at Class II groups (where the enzymatic activity is lost). Although Class I groups are labelled more readily than are Class II groups they are only slightly more susceptible to reduction by ascorbate than the Class II groups, indicating no major difference in environment. The spectral difference observed between immobilized and mobile spin-labels with both Class I and Class II groups labelling is not reflected in widely different reduction kinetics for these two spectral components. Solubilization of the enzyme in an active form does not change the protein structure in terms of increased accessibility of the SH-groups to reduction by ascorbate. The results are discussed in terms of the location of the different SH-groups and the origins of the differences in mobility evident in the EPR spectra of the spin-labelled SH-groups.",
keywords = "Animals, Ascorbic Acid, Cyclic N-Oxides, Dogfish, Electron Spin Resonance Spectroscopy, Kinetics, Maleimides, Oxidation-Reduction, Phosphorylation, Salt Gland, Sodium-Potassium-Exchanging ATPase, Solubility, Spin Labels, Sulfhydryl Compounds",
author = "Mikael Esmann and K Hideg and D Marsh",
year = "1992",
month = "12",
day = "9",
language = "English",
volume = "1112",
pages = "215--225",
journal = "B B A - General Subjects",
issn = "0304-4165",
publisher = "Elsevier BV",
number = "2",

}

RIS

TY - JOUR

T1 - Analysis of thiol-topography in Na,K-ATPase using labelling with different maleimide nitroxide derivatives

AU - Esmann, Mikael

AU - Hideg, K

AU - Marsh, D

PY - 1992/12/9

Y1 - 1992/12/9

N2 - Spin-label EPR spectroscopy of shark rectal gland Na,K-ATPase modified at cysteine residues with a variety of maleimide-nitroxide derivatives is used to characterize the different classes of sulphydryl groups. The spin-labelled derivatives vary with respect to charge and lipophilicity, and the chemical reactivity towards modification and inactivation of the Na,K-ATPase is dependent on these properties. Ascorbate is used to reduce the spin-labels in situ, and the kinetics of reduction of the protein-bound spin-labels are found also to depend on the nature of the maleimide-nitroxide derivative. The Na,K-ATPase is labelled either at Class I groups (with retention of enzymatic activity) or at Class II groups (where the enzymatic activity is lost). Although Class I groups are labelled more readily than are Class II groups they are only slightly more susceptible to reduction by ascorbate than the Class II groups, indicating no major difference in environment. The spectral difference observed between immobilized and mobile spin-labels with both Class I and Class II groups labelling is not reflected in widely different reduction kinetics for these two spectral components. Solubilization of the enzyme in an active form does not change the protein structure in terms of increased accessibility of the SH-groups to reduction by ascorbate. The results are discussed in terms of the location of the different SH-groups and the origins of the differences in mobility evident in the EPR spectra of the spin-labelled SH-groups.

AB - Spin-label EPR spectroscopy of shark rectal gland Na,K-ATPase modified at cysteine residues with a variety of maleimide-nitroxide derivatives is used to characterize the different classes of sulphydryl groups. The spin-labelled derivatives vary with respect to charge and lipophilicity, and the chemical reactivity towards modification and inactivation of the Na,K-ATPase is dependent on these properties. Ascorbate is used to reduce the spin-labels in situ, and the kinetics of reduction of the protein-bound spin-labels are found also to depend on the nature of the maleimide-nitroxide derivative. The Na,K-ATPase is labelled either at Class I groups (with retention of enzymatic activity) or at Class II groups (where the enzymatic activity is lost). Although Class I groups are labelled more readily than are Class II groups they are only slightly more susceptible to reduction by ascorbate than the Class II groups, indicating no major difference in environment. The spectral difference observed between immobilized and mobile spin-labels with both Class I and Class II groups labelling is not reflected in widely different reduction kinetics for these two spectral components. Solubilization of the enzyme in an active form does not change the protein structure in terms of increased accessibility of the SH-groups to reduction by ascorbate. The results are discussed in terms of the location of the different SH-groups and the origins of the differences in mobility evident in the EPR spectra of the spin-labelled SH-groups.

KW - Animals

KW - Ascorbic Acid

KW - Cyclic N-Oxides

KW - Dogfish

KW - Electron Spin Resonance Spectroscopy

KW - Kinetics

KW - Maleimides

KW - Oxidation-Reduction

KW - Phosphorylation

KW - Salt Gland

KW - Sodium-Potassium-Exchanging ATPase

KW - Solubility

KW - Spin Labels

KW - Sulfhydryl Compounds

M3 - Journal article

C2 - 1333803

VL - 1112

SP - 215

EP - 225

JO - B B A - General Subjects

JF - B B A - General Subjects

SN - 0304-4165

IS - 2

ER -