Insulin Like Growth Factor Binding Protein 7 (IGFBP7)

By Northern blot analysis, Oh et al. (1996) found that mac25, or IGFBP7, wajs expressed as a 1.1-kb transcript in a broad spectrum of normal tissues. These authors reported that the predicted 277-amino acid protein contains a 26-amino acid signal sequence and the IGFBP motif (GCGCCXXC) at the N terminus. The IGFBP motif is located in a region containing a cluster of 12 conserved cysteines, of which 11 are found in IGFBP7.

The amino acid sequences of IGFBP7 and IGFBPs share 20 to 25% identity. Oh et al. (1996) found that recombinant IGFBP7 specifically bound IGFs, although with relatively low affinity. Kim et al. (1997) proposed that IGFBP7, CTGF , NOV , and IGFBP10  constitute a subfamily of low-affinity IGFBPs.