title: Bionanocapsule-based enzyme-antibody conjugates for enzyme-linked immunosorbent assay.
abstract: Macromolecules that can assemble a large number of enzyme and antibody molecules have been used frequently for improvement of sensitivities in enzyme-linked immunosorbent assays (ELISAs). We generated bionanocapsules (BNCs) of approximately 30nm displaying immunoglobulin G (IgG) Fc-binding ZZ domains derived from Staphylococcus aureus protein A (designated as ZZ-BNC). In the conventional ELISA using primary antibody and horseradish peroxidase-labeled secondary antibody for detecting antigen on the solid phase, ZZ-BNCs in the aqueous phase gave an approximately 10-fold higher signal. In Western blot analysis, the mixture of ZZ-BNCs with secondary antibody gave an approximately 50-fold higher signal than that without ZZ-BNCs. These results suggest that a large number of secondary antibody molecules are immobilized on the surface of ZZ-BNCs and attached to antigen, leading to the significant enhancement of sensitivity. In combination with the avidin-biotin complex system, biotinylated ZZ-BNCs showed more significant signal enhancement in ELISA and Western blot analysis. Thus, ZZ-BNC is expected to increase the performance of various conventional immunoassays.
authors.affiliation: Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Masumi
authors.initials: M
authors.lastname: Iijima
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuzaki
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kadoya
authors.forename: Satoko
authors.initials: S
authors.lastname: Hatahira
authors.forename: Shingo
authors.initials: S
authors.lastname: Hiramatsu
authors.forename: Giman
authors.initials: G
authors.lastname: Jung
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Tanizawa
authors.forename: Shun'ichi
authors.initials: S
authors.lastname: Kuroda
mesh_terms: D000906:Antibodies / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D001360:Avidin / Q000378:metabolism; D001710:Biotin / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D053769:Nanocapsules / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D013205:Staphylococcal Protein A / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000906:Antibodies; D055767:Immobilized Proteins; D007141:Immunoglobulin Fc Fragments; D053769:Nanocapsules; D013205:Staphylococcal Protein A; D001360:Avidin; D001710:Biotin