Figure 7

Oligomeric state of improved FbFP F37S mutant. Oligomeric states of native and mutant FbFPs were determined by size exclusion chromatography. Chromatograms of (a) wild type FbFP and (b) FbFP F37S from size exclusion chromatography. The F37S mutant and wild type FbFP were run through the Superdex 200 column under conditions identical to those used for the protein standards. FbFP F37S and wild type FbFP elute at similar volumes, thereby confirming that the native and mutant proteins have identical oligomeric conformations (dimeric). (c) Calibration plot for estimation of molecular mass using size exclusion chromatography. Globular proteins of known molecular weights were loaded onto a Superdex 200 gel filtration column and protein elution volumes corresponding to peak absorbance at 280 nm were recorded. A semi-logarithmic plot of molecular weight against elution volume yielded a straight line whose slope was used to calculate the molecular mass of the FbFP wild type and mutants.