Native exchange NMR None ΔG(HX0) > 10; m-value > 10 KQNVSSLDEKNSVSVDLPGEMKVLVSKEKNKDGKYDLIATVDKLELKGTSDKNNGSGVLEGVKADKSKVKLTISDDLGQTTLEVFKEDGKTLVSKKVTSKDKSSTEEKFNEKGEVSEKIITRADGTRLEYTGIKSDGSGKAKEVLKGYVLEGTLTAEKTTLVVKEGTVTLSKNISKSGEVSVELNDTDSSAATKKTAAWNSGTSTLTITVNSKKTKDLVFTKENTITVQQYDSNGTKLEGSAVEITKLDEIKNALK

15N- and 13C, 15N-labeled OspA was prepared as described. HX was initiated by rapid buffer exchange of 15N-labeled, 1 mM OspA using a Sephadex G25 (Pharmcia) spin column to D2O buffer containing 10 mM sodium phosphate and 0 – 0.6 M Gu2HCl. This buffer contained NaCl, so that the sum of [Gu2HCl] and [NaCl] was kept at 0.65 M. Immediately following buffer exchange, a series of 1H, 15N-HSQC spectra were recorded at 37 °C on a Varian 600 spectrometer. The pH (uncorrected) of each sample was determined after NMR measurements.

Native exchange NMR None 7 < ΔG(HX0) < 10; m-value > 7 KQNVSSLDEKNSVSVDLPGEMKVLVSKEKNKDGKYDLIATVDKLELKGTSDKNNGSGVLEGVKADKSKVKLTISDDLGQTTLEVFKEDGKTLVSKKVTSKDKSSTEEKFNEKGEVSEKIITRADGTRLEYTGIKSDGSGKAKEVLKGYVLEGTLTAEKTTLVVKEGTVTLSKNISKSGEVSVELNDTDSSAATKKTAAWNSGTSTLTITVNSKKTKDLVFTKENTITVQQYDSNGTKLEGSAVEITKLDEIKNALK

15N- and 13C, 15N-labeled OspA was prepared as described. HX was initiated by rapid buffer exchange of 15N-labeled, 1 mM OspA using a Sephadex G25 (Pharmcia) spin column to D2O buffer containing 10 mM sodium phosphate and 0 – 0.6 M Gu2HCl. This buffer contained NaCl, so that the sum of [Gu2HCl] and [NaCl] was kept at 0.65 M. Immediately following buffer exchange, a series of 1H, 15N-HSQC spectra were recorded at 37 °C on a Varian 600 spectrometer. The pH (uncorrected) of each sample was determined after NMR measurements.

Native exchange NMR None 5 < ΔG(HX0) < 8; 5 < m-value < 6 KQNVSSLDEKNSVSVDLPGEMKVLVSKEKNKDGKYDLIATVDKLELKGTSDKNNGSGVLEGVKADKSKVKLTISDDLGQTTLEVFKEDGKTLVSKKVTSKDKSSTEEKFNEKGEVSEKIITRADGTRLEYTGIKSDGSGKAKEVLKGYVLEGTLTAEKTTLVVKEGTVTLSKNISKSGEVSVELNDTDSSAATKKTAAWNSGTSTLTITVNSKKTKDLVFTKENTITVQQYDSNGTKLEGSAVEITKLDEIKNALK

15N- and 13C, 15N-labeled OspA was prepared as described. HX was initiated by rapid buffer exchange of 15N-labeled, 1 mM OspA using a Sephadex G25 (Pharmcia) spin column to D2O buffer containing 10 mM sodium phosphate and 0 – 0.6 M Gu2HCl. This buffer contained NaCl, so that the sum of [Gu2HCl] and [NaCl] was kept at 0.65 M. Immediately following buffer exchange, a series of 1H, 15N-HSQC spectra were recorded at 37 °C on a Varian 600 spectrometer. The pH (uncorrected) of each sample was determined after NMR measurements.