CD analysis of MBP-linker-MPR-TM, MPR-TM and MBP.

<p>(A) CD spectra of MBP-linker-MPR-TM, MPR-TM and MBP. Buffer: 100 mM NaF, 20 mM NaH₂PO₄, pH 7.5, and 0.02% βDDM. Protein concentration was 0.26 mg/mL. (B) Thermal denaturation curve of MBP-linker-MPR-TM measured at 220 nm and at a rate of temperature change of 2°C/min. The apparent midpoint “denaturation” temperature of the protein was 50°C. Protein concentration was 0.5 mg/mL. (C) Effect of ionic strength on the secondary structure of MBP-linker-MPR-TM. CD measurements were performed in 20 mM Tris, pH 7.5, 0.02% βDDM containing 0 to 300 mM NaCl. (D) Effect of pH on the secondary structure of MBP-linker-MPR-TM. CD spectra were recorded in 150 mM NaCl, 0.02% βDDM at pH 6.5 to 8.5.