A novel approach to ultrasensitive diagnosis using supramolecular protein nanoparticles.
We report on the ultrasensitive protein nanoprobe system that specifically captures disease marker (autoantibodies of Type I diabetes in this case) with attomolar sensitivity. The system relies on supramolecular protein nanoparticles that bind a specific antibody [65 kDa glutamate decarboxylase (GAD65)-specific autoantibody, i.e., the early marker of Type I diabetes]. The ultrasensitive detection of early marker of Type I diabetes during the early phase of pancreatic beta-cell destruction is important because individuals at high risk of developing Type I diabetes can be identified several years before the clinical onset of the ailment. The bacterial expression of chimera genes encoding N-[human ferritin heavy chain (hFTN-H)]::[specific antigenic epitope]-C produces supramolecular nanoparticles with uniform diameters (10-15 nm), owing to self-assembly activity of hFTN-H. Each nanoparticle, formed by intermolecular self-assembly between the chimera protein molecules, is subjected to carrying a large number (presumably, 24) of epitopes with a homogeneous and stable conformation per autoantibody binding, thereby allowing substantial enhancement of sensitivity. The sensitivity was finally boosted to 3 attomolar concentration of the autoantibodies, 4-9 orders of magnitude more sensitive than conventional immunoassays. Also, this ultrasensitive protein nanoprobe successfully detected natural autoantibodies in the sera from Type I diabetic patients. The attomolar sensitivity was successfully reproduced on the detection of other antibodies, i.e., monoclonal antibodies against hepatitis B surface antigen. With the two antibody markers above, the feasibility of simultaneous and multiplexing-mode detection was also demonstrated.
Lee
Sung-Hyun
SH
Department of Chemical and Biological Engineering, Korea University, Seoul, South Korea.
Lee
Hyewon
H
Park
Jin-Seung
JS
Choi
Hyoung
H
Han
Kyung-Yeon
KY
Seo
Hyuk-Seong
HS
Ahn
Keum-Young
KY
Han
Sung-Sik
SS
Cho
Yunjung
Y
Lee
Kee-Hyoung
KH
Lee
Jeewon
J
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000032:analysis*; D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis*; D002648:Child; D017931:DNA Primers; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007527:Isoenzymes / Q000276:immunology*; D008297:Male; D053758:Nanoparticles; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000737:chemistry*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D001323:Autoantibodies; D015415:Biomarkers; D017931:DNA Primers; D007527:Isoenzymes; D011506:Proteins; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2