Otoraplin (OTOR), human recombinant

TOR proteins is also known as fibrocyte-derived protein (Fdp) and Melanoma inhibitory activity-like (MIAL). Otoraplin is a member of the melanoma-inhibiting activity gene family. Otoraplin is a secreted 16 kDa globular protein that is expressed in the inner ear by periotic mesenchyme and developing and mature fibrocytes. OTOR is highly homologous to MIA/cartilage-derived retinoic acid-sensitive protein (CD-RAP), which is a cartilage-specific protein that is also expressed in malignant melanoma cells. The 111 amino acid mature human otoraplin contains 1 SH3 domain (46 –107 amino acids) and a Tyr at position 50 that is reportedly sulfated. Otoraplin takes part in the initiation of periotic mesenchyme chondrogenesis. Otoraplin is secreted through the Golgi apparatus and plays a role in cartilage development and maintenance. A frequent polymorphism in the translation start codon of OTOR can abolish translation and may be associated with forms of deafness. Recombinant human Otoraplin produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 111 amino acids and having a molecular mass of 12.7 kDa.The OTOR is purified by proprietary chromatographic techniques.