Figure 4
Conformational analyses of purified recombinant HTT-exon1 proteins.
(a) SDS-PAGE analysis of the expression and purification of recombinant MBP tagged HTT-exon1 fusion proteins. Lane 1–3, MBP-Q25, lane 4–6, MBP-Q72. Lane M, the protein molecular weight marker; lane 1 and 4, the supernatants loaded on Ni-NTA column; lane 2 and 5, the eluates of Ni-NTA chromatography; lane 3 and lane 6, the eluates of Superdex 200 size exclusive chromatography for TR-FRET and CD analysis. (b) 2B7/MW1 TR-FRET signals of HTT-exon1 proteins at 4°C and room temperature. Note that the temperature sensitivity is much higher for Q25 than Q72. (c) CD data for the MBP-Q25 and MBP-Q72 at 4°C and 37°C. Red line: MBP-Q25 at 4°C, pink line: MBP-Q25 at 37°C, green line: MBP-Q72 at 4°C and blue line: MBP-Q72 at 37°C. (d) Estimated secondary structure contents of MBP-Q25 and MBP-Q72 at 4°C and 37°C by the linear regression method.
