Preparation from bovine colostrum of a fraction rich in latent transforming growth factor-β2 and cleared of most allergenic proteins by one-step Cibacron Blue chromatography

A strategy was developed for the preparation of a latent transforming growth factor-β2 (latent TGF-β2) rich fraction from bovine colostrum. Different conventional chromatography techniques were tested to investigate some physicochemical properties of latent TGF-β2 complexes to optimize their recovery. Three latent TGF-β2 forms were detected by gel filtration (600, 150–250 and 65–150 kDa). Cation exchange chromatography showed that the pI of latent TGF-β2 was above pH 7; hydrophobic interaction chromatography showed that the hydrophobicity of latent TGF-β2 was much higher than that of other whey proteins. Affinity chromatography on Cibacron Blue 3G was used to separate latent TGF-β2 and immunoglobulin G from the most immunogenic proteins, α-lactalbumin, β-lactoglobulin and albumin. Optimum conditions were determined: preparation of a fraction 26 times richer in TGF-β2 than in serocolostrum was obtained with a good yield (up to 70%) of TGF-β2, 80% of which was in the latent form.