Overexpression, purification, and enthalpy of unfolding of ferricytochrome c552 from a psychrophilic microorganism

• Published in: Journal of inorganic biochemistry Vol. 131; pp. 76 - 78
• Main Authors: Oswald, Victoria F., Chen, WeiTing, Harvilla, Paul B., Magyar, John S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-02-2014
• Subjects: Colwellia; Cytochrome c Group - chemistry; Cytochrome c Group - genetics; Cytochrome c Group - isolation & purification; Cytochrome c Group - metabolism; Cytochrome c552; Escherichia coli; Escherichia coli - genetics; Gammaproteobacteria - enzymology; Protein Denaturation; Protein Folding; Protein Stability; Psychrophile; Spectrophotometry, Ultraviolet; Thermal denaturation; Van't Hoff enthalpy; Psychrophile; Thermal denaturation; Van't Hoff enthalpy; Cytochrome c552; Cytochrome c
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/j.jinorgbio.2013.11.002

The psychrophilic, hydrocarbonoclastic microorganism Colwellia psychrerythraea is important in global nutrient cycling and bioremediation. In order to investigate how this organism can live so efficiently at low temperatures (~4°C), thermal denaturation studies of a small electron transfer protein from Colwellia were performed. Colwellia cytochrome c552 was overexpressed in Escherichia coli, isolated, purified, and characterized by UV–visible absorption spectroscopy. The melting temperature (Tm) and the van't Hoff enthalpy (ΔHvH) were determined. These values suggest an unexpectedly high stability for this psychrophilic cytochrome.
Thermal denaturation of ferricytochrome c552 from Colwellia psychrerythraea; monitored by UV–vis absorption spectroscopy; calculations of Tm and van't Hoff enthalpy. [Display omitted]
•The first monoheme cytochrome from a psychrophile was overexpressed and purified.•The Tm and van't Hoff enthalpy of unfolding are reported from thermal denaturation.•This cyt c552 has a lower ΔHvH and unchanged Tm compared to mesophilic cytochromes.•Predicted protein flexibility does not correlate with overall protein stability.•Protein stability and dynamics are not coupled simply, in contrast with predictions.