Open AccessIn vivo reaction of affinity‐tag‐labelled epidermin precursor peptide with flavoenzyme EpiD
Author(s) -
Kupke Thomas,
Götz Friedrich
Publication year - 1997
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1997.tb10459.x
Subject(s) - in vivo , peptide , chemistry , biochemistry , chromatography , combinatorial chemistry , biology , microbiology and biotechnology
Abstract The Staphylococcus epidermidis genes encoding the His‐tag‐labelled epidermin precursor peptide EpiA and the flavoenzyme EpiD or the mutant protein EpiD‐G93D, which lacks the coenzyme, were co‐expressed and the proteins were synthesized in vivo in Escherichia coli . Only in the presence of EpiD was the precursor peptide converted to a reaction product with a decrease in mass of 44–46 Da. This result confirms the in vitro experiments carried out with purified EpiA and purified EpiD from Staphylococcus epidermidis [Kupke et al. (1994) J. Biol. Chem. 269, 5653–5659]. EpiD catalyzes the oxidative decarboxylation of the C‐terminal cysteine residue of EpiA to a [ Z ]‐enethiol structure. In the presence of EpiD, the amount of purified (modified) peptide EpiA was several‐fold higher than in the presence of EpiD‐G93D, indicating that the stabilization of EpiA against proteolysis is due to an interaction with EpiD or to the presence of the C‐terminal modification. The presented experimental approach will be valuable for the analysis of enzymes that catalyze posttranslational modification reactions of peptides and proteins.