Full active baculovirus-expressed human monocyte chemoattractant protein 1 with the intact N-terminus

The Sf-9 insect cells infected with a recombinant baculovirus integrated with a cDNA encoding human monocyte chemoattractant protein-1 (MCP-1) produced three different MCP-1s, which were isolated by reverse-phase HPLC as 13kDa, 14kDa, and 15kDa bands on SDS-PAGE. The heterogeneity between these MCP-1s was ascribed to the different degree of O-glycosylation with Gal beta 1-3GalNAc beta 1-Ser/Thr, while the 13kDa was regarded as carbohydrate-free. The integrity of the N-termius was confirmed by the amino acid sequence analysis. Each MCP-1 isolated showed equipotent monocyte chemotactic activity, which was rather higher than that of the E. coli-derived one.