Range |
Table - link
|
Organism |
Various |
Reference |
Lee MD, Antczak C, Li Y, Sirotnak FM, Bornmann WG, Scheinberg DA.
A new human peptide deformylase inhibitable by actinonin. Biochem Biophys Res Commun. 2003 Dec 12 312(2):309-15PubMed ID14637138
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Method |
Cloning of HsPDF cDNA. Expression and purification of HsPDF. The expression vectors encoding the HsPDF cDNAs were transformed into BL21(DE3)pLysS cells (Novagen) and grown in LB media containing 50 µg/ml kanamycin and 34 µg/ml chloramphenicol at 37 °C until OD600 reached 0.4. Cells were then induced with 0.5 mM IPTG and incubated at 30 °C for 18 h. Peptide deformylase assays. Three different assays were used to study the kinetic properties of HsPDF. Method I is an indirect spectrophotometric assay [15] that couples peptide deformylase activity with formate dehydrogenase (FDH) activity. Method II is a continuous spectrophotometric assay for peptide deformylase activity[16] that uses fML-pNA as the substrate, which is first deformylated and then subsequently processed by Aeromonas proteolytica aminopeptidase (AAP) to release p-nitroaniline. Method III is a direct solid phase fluorescent assay to measure peptide deformylase activity and is based on a previously published method using fluorescamine to detect the formation of the new amino group of the N-formylated substrate after deformylation. In order to examine some standard enzymatic parameters, researchers used the cobalt-containing form of HsPDF to conduct basic kinetic studies. They examined the use of different formylated peptides as potential substrates and found that HsPDF was able to deformylate fMAS, fML-pNA, but not fMLP (Fig. 2 and Table 1). They found that at concentrations above 20 mM of fMAS, the substrate inhibited the human enzyme, an observation that has been noted previously with EcPDF [20]. The Kcat/Km values for HsPDF were significantly lower than the published EcPDF, AtPDF1A, and PfPDF values |
Comments |
Peptide deformylase (PDF) activity was thought to be limited to ribosomal protein synthesis in prokaryotes, where new peptides are initiated with an N-formylated methionine. It has since been discovered in eukaryotes including Thale cress (arabidopsis) and humans. |
Entered by |
Uri M |
ID |
104974 |