Improved efficacy of soluble human receptor activator of nuclear factor kappa B (RANK) fusion protein by site-directed mutagenesis. (June 2015)

• Record Type: Journal Article
• Authors: Son, Young Jun; Han, Jihye; Lee, Jae Yeon; Kim, HaHyung; Chun, Taehoon
• Is Part Of: Immunopharmacology and immunotoxicology. Volume 37:Number 3(2015:Jun.)
• Page Start: 221
• Page End: 227
• Publication Date: 2015-06
• Subjects: Immunopharmacology -- Periodicals; Immunotoxicology -- Periodicals; Antibody-toxin conjugates -- Periodicals; Immunology -- Periodicals; 615.37
• DOI: 10.3109/08923973.2015.1035392
• Languages: English
• ISSNs: 0892-3973

Abstract

<abstract> <title>Abstract</title> <p>Soluble human receptor activator of nuclear factor kappa B fusion immunoglobulin (hRANK-Ig) has been considered as one of the therapeutic agents to treat osteoporosis or diseases associated with bone destruction by blocking the interaction between RANK and the receptor activator of nuclear factor kappa B ligand (RANKL). However, no scientific record showing critical amino acid residues within the structural interface between the human RANKL and RANK complex is yet available. In this study, we produced several mutants of hRANK-Ig by replacement of amino acid residue(s) and tested whether the mutants had increased binding affinity to human RANKL. Based on the results from flow cytometry and surface plasmon resonance analyses, the replacement of E¹²⁵ with D¹²⁵, or E¹²⁵ and C¹²⁷ with D¹²⁵ and F¹²⁷ within loop 3 of cysteine-rich domain 3 of hRANK-Ig increases binding affinity to human RANKL over the wild-type hRANK-Ig. This result may provide the first example of improvement in the efficacy of hRANK-Ig by protein engineering and may give additional information to understand a more defined structural interface between hRANK and RANKL.</p> </abstract>