Creative Biolabs offers customers scaffold library construction services for monobodies, antibody mimics based on the scaffold of the Fibronectin Type III Domain. The innovative trimer-codon technology and NNK method have been developed to construct scaffold libraries with excellent controllability and operability.
Monobodies are engineered antibody mimics based on the scaffold of the 10th fibronectin type III domain of human fibronectin (FNfn10). The properties of FNfn10 make it an ideal candidate for a molecular scaffold. FNfn10 is a small (94 residues) and monomeric protein. It is very stable even without disulfide bonds or metal ions, and can be highly expressed in the correctly folded form in bacteria. FNfn10 is composed of a β-sandwich structure similar to that of the variable domain of a heavy chain. It contains three variable loops on each end, which can be potentially used to present multiple peptide segments. Besides these diversified residues in the variable loops, additional randomizable positions on the β sheets can be utilized to generate a monobody library as well, with an expected diversity of ≥1010.
Figure 1. An monobody in complex with the SH2 domain (PDB ID 4JE4). (Christian Jost et al., 2014)
High-affinity and isoform-specific monobodies were developed as inhibitors of small ubiquitin-related modifier (SUMO) family proteins, and used to for the mechanistic and cellular investigations of SUMO biology. Monobodies targeting the enzyme beta-galactosidase can prevent it from producing long sugar chains. Hormonal therapy and chemotherapy have been used traditionally for systemic treatments of advanced disease. However, responses to treatment are often short-lived, with advanced-stage disease being incurable. Prolactin was shown as a key factor in endometrial and ovarian cancer, under which scenarios, the circulating level prolactin inceased. Prolactin-transformed cells can grow in soft agar and form tumors in a mouse model. A human anti-PRLR monobody was developed as an innovative treatment for gynecologic cancer. Their functions were evaluated in vitro and in a murine tumor model. Actin remodeling and cancer cell movement were shown to be negatively affected.
There are other applications associated with monobodies. We can build monobody libraries and screen the members for stable, functional and specific monobodies depending on your research objectives.