Figure 3.

Folding of hβ₂m and mβ₂m in real-time. (A) ¹H–¹⁵N SOFAST HSQC spectrum of native hβ₂m in 10 mM sodium phosphate pH 6.2. (B) The ¹H–¹⁵N SOFAST HSQC spectrum of hβ₂m collected 3 min after refolding was initiated by urea dilution. Peaks that are already in their native positions are colored gray, while peaks with non-native chemical shifts are shown in red. (C) The ¹H–¹⁵N HSQC spectrum of ΔN6 closely resembles the spectrum of the real-time folding intermediate of hβ₂m. An overlay of the spectra shown in B and C is shown as an inset. (D) ¹H–¹⁵N HSQC spectrum of native mβ₂m in 10 mM sodium phosphate pH 6.2. (E) The ¹H–¹⁵N BEST-TROSY-HSQC of mβ₂m collected 3 min after refolding was initiated by urea dilution. Peaks that are already in their native positions are colored green while peaks with non-native chemical shifts are shown in purple. (F) The ¹H–¹⁵N HSQC spectrum of mβ₂m at pH 3.6 closely resembles the spectrum of the real-time folding intermediate of mβ₂m.