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Dynamic structure of metallothionein
Author(s) -
Vašák Milan,
Berger Christine,
Kägi Jeremias H.R.
Publication year - 1984
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(84)80230-6
Subject(s) - metallothionein , circular dichroism , ionic strength , chemistry , intramolecular force , stokes radius , crystallography , conformational change , biophysics , protein structure , stereochemistry , biochemistry , size exclusion chromatography , enzyme , biology , aqueous solution , gene
Molecular sieve chromatography of rabbit liver metallothionein at different electrolyte concentrations revealed that this protein undergoes an increase in Stokes radius from 1.50 to 1.78 nm when the ionic strength is lowered from 0.5 to 0.015 indicating a change in molecular shape and/or hydration. The variation in ionic strength also affects the far‐UV circular dichroism of metallothionein reflecting a conformational transition in the protein. The effects are attributed to changes in intramolecular repulsion between the strongly negatively charged metal‐thiolate clusters of the protein. It is suggested that metallothionein exists in at least two interchangeable conformational states which differ in hydrodynamic properties and whose equilibrium concentrations are determined by the electrostatic free energy of the system.