Figure 6. Effect of glycosylation on purified TibA.

TibA was purified from E. coli strain C600 bearing plasmids allowing expression of glycosylated and unglycosylated TibA and solubilized in TBS 1% n-octyl-β-D-glucoside. (A) Far-UV CD spectrum of glycosylated TibA (black) and unglycosylated TibA (red) are shown between 205 and 260 nm. (B) Proteins were also subjected to a thermal denaturation followed by a renaturation monitored by far-UV CD. Temperature was increased from 25°C and 80°C at a rate of 5°C per minute and the ellipticities at 218 nm were recorded for glycosylated TibA (black) and unglycosylated TibA (red). Right after the denaturation, temperature was decreased from 80°C to 25°C at a rate of 5°C per minute and the ellipticities were recorded at 218 nm for glycosylated TibA (gray) and unglycosylated TibA (orange).