M-CSF, sucrose formulation

A protein expressed from a DNA sequence encoding the N-terminal 190 amino acids of the human Macrophage Colony-Stimulating Factor 1 (M-CSF) protein was expressed in modified human 293 cells.  In this formulation 1% sucrose has been added to aid in freeze thaw stability.

M-CSF (macrophage colony stimulating factor), also known as colony stimulating factor-1 (CSF-1), is a homodimeric glycoprotein, the subunits of which are linked by disulfide bonds. Symansis' M-CSF^hcx has N- and O-linked oligosaccharides, shown by a drop in observed MW on SDS-PAGE after treatment with PNGase F and a further drop after treatment with a glycosidase cocktail. Symansis' M-CSF^hcx contains 0-50% carbohydrate by weight.

Densitometry of protein isoforms visualised by 2-DE. Spot trains are normal in human proteins and highlight the presence of multiple isoforms which differ according to their level of post-translational modification. The triangle indicates the theoretical MW and pI of the protein.

1D SDS-PAGE of Symansis' hcx protein before and after treatment with glycosidases to remove oligosaccharides. A drop in the observed MW after treatment indicates the presence of glycosylation.

1. Chitu and Stanley (2006) Current Opinion in Immunology 18:39-48