Improved system for heterologous expression of cytochrome c mutants in Escherichia coli

Katalin Tenger, P. Khoroshyy, K. L. Kovács, L. Zimányi, G. Rákhely

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We improved an already existing cytochrome c expression system to a reliable, tightly controllable one to achieve a higher expression yield for single cysteine mutants of horse cytochrome c. The protein is heterologously overexpressed in E. coli together with the maturation coordinating enzyme heme lyase from yeast. Various plasmid constructs and host strains were tested for protein expression yield and routinely around 35 mg/L yield was achieved, which is a good result for a post-translationally modified enzyme. The purpose of producing cysteine mutants is to position accessible cysteine residues on the surface of cytochrome c which can be labeled with a photoactive redox dye, 8-thiouredopyrene-1,3,6-trisulfonate, TUPS. TUPS labeled proteins have been used for intramolecular and intermolecular electron transfer measurements. Here, we initiate the photoreduction of cytochrome c oxidase, the natural electron acceptor partner of cytochrome c by an appropriate cytochrome c mutant labeled with TUPS. The electron transfer from cytochrome c to the first cytochrome oxidase redox cofactor, copper A, is shown to be very fast.

Original languageEnglish
Pages (from-to)23-35
Number of pages13
JournalActa biologica Hungarica
Volume58
Issue numberSUPPL. 1
DOIs
Publication statusPublished - Nov 1 2007

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Keywords

  • Cytochrome c oxidase, site directed mutagenesis, kinetic spectroscopy
  • Electron transfer
  • Heme lyase

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Environmental Science(all)
  • Neurology

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