Preparation from bovine colostrum of a fraction rich in latent transforming growth factor-o2 and cleared of most allergenic proteins by one-step Cibacron Blue chromatography

摘要

A strategy was developed for the preparation of a latent transforming growth factor-@b2 (latent TGF-@b2) rich fraction from bovine colostrum. Different conventional chromatography techniques were tested to investigate some physicochemical properties of latent TGF-@b2 complexes to optimize their recovery. Three latent TGF-@b2 forms were detected by gel filtration (600, 150-250 and 65-150kDa). Cation exchange chromatography showed that the pI of latent TGF-@b2 was above pH 7; hydrophobic interaction chromatography showed that the hydrophobicity of latent TGF-@b2 was much higher than that of other whey proteins. Affinity chromatography on Cibacron Blue 3G was used to separate latent TGF-@b2 and immunoglobulin G from the most immunogenic proteins, @a-lactalbumin, @b-lactoglobulin and albumin. Optimum conditions were determined: preparation of a fraction 26 times richer in TGF-@b2 than in serocolostrum was obtained with a good yield (up to 70%) of TGF-@b2, 80% of which was in the latent form.