Development of new immunodiagnostic platforms based on non-immunoglobulin protein scaffold

Abstract

In these days, all of mankind is interested in medical treatment and diagnosis of disease in early stage. Especially, early stage diagnosis is important for prevention of pandemic in developing countries. There have been many efforts for early stage diagnosis, however, most of detection system is not efficient enough for point of care diagnosis. Most of protein based diagnostic systems are utilizing expensive anti-bodies as capturing protein and the detection instruments are not portable. In this study, portable and cost-effective diagnostic system based on non-immunoglobulin protein scaffold was developed. Non-immunoglobulin protein scaffold was developed as alternative protein of traditional antibodies. Protein scaffolds have several beneficial things compared to antibodies

i) smaller size, ii) higher productivity in bacterial hosts, iii) higher thermal and chemical stability. Among those protein scaffolds, kringle domain was engineered to have binding affinity to H1 and N1 antigens of H1N1 influenza virus based on fluores-cence activated cell sorting (FACS) screening method. Due to the high stability of kringle domain, it has high possibility to be applied to the fabrication of diagnostic platform. And new protein immobilization platform was established for the generation of cost-effective and portable diagnostic system. Through the protein immobilization platform, kringle domain could be immobilized on cost-effective substrates such as chromatography paper. Finally, highly sensitive and efficient diagnostic platform using kringle domain as affinity protein was developed. The fusion protein of GFP and kringle domain was displayed on the metal nanoparticle and it showed highly improved sensitivity in new immunodiagnostic platform. This new diagnostic platform using protein scaffold will extensively contribute to early stage detection of disease.