Figure 1.

Effect of protein concentration on conformation. (A) Unsmoothed far-UV CD spectra of wild-type N-62 StAR recorded in a 1-mm path-length cuvette between 195 nm and 250 nm for protein concentrations of 0.125 mg/ml (wave 1), 0.187 mg/ml (wave 2), 0.250 mg/ml (wave 3), 0.312 mg/ml (wave 4), 0.387 mg/ml (wave 5), 0.449 mg/ml (wave 6), 0.512 mg/ml (wave 7), and 0.574 mg/ml (wave 8), and in a 0.1-mm path-length cuvette for a protein concentration of 7.5 mg/ml (wave 9), all at pH 4.5. (B) Correlation between protein concentration and ellipticity (Θ) at 208 and 222 nm, indicating that the protein conformation is independent of concentration.