Figure 1. Structure and Maturation process of GDF11. GDF11 is cleaved by PCSK5 to form an inactive latent complex, which contains an N-terminal inhibitory pro-domain and two disulfide-linked carboxyl-terminal active domains. Then, members of the BMP1/Tolloid family of metalloproteinases cleave the latent complex at a single specific site to form the mature GDF11 and pro-peptide.