2.6. Circular dichroism

CD measurements were carried out on a Jasco J-810 spectropolarimeter (Jasco, Easton, MD) employing a scan speed of 50 nm/min, a 4 nm band pass and an average response time of 4 s, at 37 °C in a Peltier temperature–controlled sample compartment. Spectra were an average of at least 6 scans. Spectra of reduced and oxidized 20 µM E7 were taken on 0.1 cm path length cells in 10 mM potassium phosphate buffer, pH 7.5. Oxidation was triggered by adding 0.15 mM H₂O₂ to the reduced protein in the CD cell.