Metal-selective stability of Escherichia coli NikR.
Contributors: University of Toronto.  Dept. of Chemistry.
Published: 2004
Language: eng
Number of pages: 33
Description: Escherichia coli NikR is a nickel-responsive transcription factor that regulates intracellular concentrations of nickel. To examine the unfolding of NikR and the effects of metal-binding on NikR's thermodynamic stability, circular dichroism and electronic absorption spectroscopy were used to monitor the denaturation of NikR when induced by guanidine hydrochloride or by heat. Metal-binding stabilizes significantly both the full-length protein and its isolated metal-binding domain and this stabilization is greater for Ni(II) than any other metal tested, including Cu(II), Zn(II), Mn(II), Co(II) and Cd(II). Unexpectedly, the thermally denatured protein is capable of binding Ni(II) and Cu(II), however no metal-binding to the chemically unfolded protein was observed. Only the chemical denaturation of NikR was reversible, but this data could not be fit to a variety of two-state and three-state equilibrium models including dimer-monomers, tetramer-monomers, tetramer-dimers-monomers and linear denaturant binding models. The implications of these experiments on NikR's role as a metalloregulator are discussed.
Notes: Adviser:  Deborah Zamble.

Thesis (M.Sc.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Masters Abstracts International, Volume: 43-03, page: 0850.

MICR copy on microfiche (1 microfiche).