Purity >98% by SDS-PAGE and RP-HPLC. Growth Differentiation Factor 5 Human Recombinant produced in E.Coli is a homodimer, non-glycosylated polypeptide chain containing 2 x 120 amino acids and having a total molecular mass of 27.4kDa. To enable bacterial expression the N-terminal sequence of Ala-Pro-Leu-Thr was replaced with a Lys.GDF5 is purified by proprietary chromatographic techniques.