Figure 2.
Folded states of EXGWT and EXGQQQW in solution and in the gas phase. (A) CD spectroscopy in the far-UV region shows near-identical secondary structures in 10 mM sodium phosphate buffer pH 7. In 50% acetonitrile, EXGQQQW, but not EXGWT, converts to random coil. Greyed-out parts of the curves exhibited HT voltages above 700 V, indicating increased spectral noise. (B) ESI-MS shows a slight increase of the average charge to 5.7 for both proteins sprayed from 50% acetonitrile. (C) In 100 mM AmAc, the 6+ charge states of EXGWT and EXGQQQW have similar CCS distributions. (D) In 50% acetonitrile, the CCS distribution for EXGQQQW shows an extra peak around 1550 Å2, indicating a second, more unfolded population.