In vitro selection of aptamers with affinity for neuropeptide Y using capillary electrophoresis.
Capillary electrophoresis-systematic evolution of ligands by exponential enrichment (CE-SELEX) was used to select aptamers for neuropeptide Y (NPY). This is the first example of a CE-SELEX selection for aptamers that bind a target molecule smaller than itself. One of the limitations of CE-SELEX is that the aptamer must exhibit a significant mobility shift when it binds the target to facilitate fraction collection. Before this study, it was not clear if smaller targets would be capable of inducing a large enough shift in mobility for CE-SELEX to be successful. NPY is a 36-amino acid peptide (MW = 4272 g/mol), much smaller than the 80-base ssDNA used in the selection ( approximately 25 kDa). NPY binding aptamers with 300-1000 nM dissociation constants were obtained after only four rounds of selection. The specificity of the aptamers was tested using human pancreatic polypeptide (hPP). hPP is a 36-amino acid peptide with approximately 50% homology with NPY. Aptamers with up to 42-fold selectivity for NPY over hPP were observed.
Mendonsa
Shaun D
SD
Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA.
Bowser
Michael T
MT
D015374:Biosensing Techniques / Q000379:methods; D004247:DNA / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D009478:Neuropeptide Y / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*
D009478:Neuropeptide Y; D009841:Oligonucleotides; D012313:RNA; D004247:DNA