Label-free detection of the aptamer binding on protein patterns using Kelvin probe force microscopy (KPFM).
Anti-lysozyme aptamers are found to preferentially bind to the edge of a tightly packed lysozyme pattern. Such edge-binding is due to the better accessibility and flexibility of the edge lysozyme molecules. Kelvin probe force microscopy (KPFM) was used to study the aptamer-lysozyme binding. Our results show that KPFM is capable of detecting the aptamer-protein binding down to the 30 nm scale. The surface potential of the aptamer-lysozyme complex is approximately 12 mV lower than that of the lysozyme. The surface potential images of the aptamer-bound lysozyme patterns have the characteristic shoulder steps around the pattern edge, which is much wider than that of a clean lysozyme pattern. These results demonstrate the potentials of KPFM as a label-free method for the detection of protein-DNA interactions.
Gao
Pei
P
Department of Chemistry, University of Kentucky, Rose Street, Lexington, KY 40506, USA.
Cai
Yuguang
Y
D052157:Aptamers, Nucleotide / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D020527:Microscopy, Scanning Probe / Q000379:methods*; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D013499:Surface Properties
D052157:Aptamers, Nucleotide; D009113:Muramidase