Recombinant Human BMP-3b/GDF-10 Protein

BMP-3b, also known as GDF-10, belongs to the transforming growth factor beta (TGF-beta) superfamily which includes the TGF-beta s, bone morphogenetic proteins (BMPs), growth differentiation factors (GDFs), Activins, Inhibins, Leftys, Nodal, Mullerian inhibitory substance (MIS) and the glial cell line-derived neurotrophic factors (GDNFs) (1). TGF-beta family members are synthesized and secreted as homodimeric or heterodimeric prepropeptides that are cleaved by proprotein convertases such as furin to generate the carboxy-terminal mature dimeric protein that contains the characteristic conserved cysteine residues involved in the formation of the cysteine knot domain. Within pro-BMP-3b, three dibasic cleavage sites have been identified. Mature BMP-3B is a disulfide-linked homodimer of the C-terminal 110 amino acids. Among TGF-beta  family members, BMP-3b is most closely related to BMP-3, sharing 83% and 30% amino acid sequence identity in their mature and pro regions, respectively (2, 3). BMP-3b is highly conserved across animal species, the aa sequence of mature human BMP-3b is 98% identical with that of the mouse or rat proteins (2, 3). BMP-3b is expressed in developing skeletal structures of the craniofacial region and the vertebral column, as well as in the adult trachea, aorta, and most abundantly in the cerebellum and uterus (2 - 4). Interestingly, in the knock-out mice, no obvious abnormalities have been found in these tissues (4). The biological function of BMP-3b is yet unknown, however studies have implicated it in the differentiation of osteoblasts, augmenting BMP-2 activity (5, 6).