Figure 5.

Purification and characterization of 30 kDa proteins. DEAE cellulose ion exchange chromatography (A) followed by Sephadex G25 gel filtration chromatography (B). The protein content for exemplary fractions (A) 33-40, (B) 53-60, was visualized using 1D-PAGE. Fractions 38-51 showed two bands in the 30 kDa region (M - 30 kDa marker; ~30, 31 kDa), fractions 12-37 three bands (~ 29, 30, 31); otherwise the gels showed no protein signals. Gel filtration allowed isolation of protein in a single band (fraction 55-60). Bands from fractions 34 (A) and 60 (B) were subjected to LC-MS/MS analysis. The samples showing only three bands of the 30 kDa proteins were pooled (PUR) and stored at -80°C for further analysis. (C) Oil red O lipoprotein staining of fractions 38 and 37 separated by 12% SDS-PAGE. (D) Crude PVFB protein was compared to PUR protein by native 7% 1D-PAGE. The latter was not resolved and detected at ~130 kDa (no marker available). (E) Electron micrograph of PUR protein, magnification 50.000.

Pakkianathan et al. BMC Biochemistry 2012 13:5   doi:10.1186/1471-2091-13-5
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