title: A high-affinity peptide for nicotinic acetylcholine receptor-α1 and its potential use in pulmonary drug delivery.
abstract: In pulmonary drug delivery, the ability of an affinity molecule to bind to lung epithelium may prolong retention of therapeutic molecules within the lung and consequently yield higher overall bioavailability. To this end, we screened a library of structurally constrained peptides ('aptides') using phage-display technology and identified a high-affinity aptide for the mouse nicotinic acetylcholine receptor-α1 (nAChR-α1). The isolated aptide (APTnAChR-α1) bound to its target protein with high affinity (Kd=47nM). Alexa 488-labeled APTnAChR-α1 showed preferential binding to nAChR-α1-positive mouse lung epithelial cells and mouse muscle cells. Furthermore, the aptide exhibited substantial binding in nAChR-α1-positive tissue sections of muscle, trachea and lung, but not in liver, kidney or spleen tissues, which are nAChR-α1-negative. In an in vivo experiment, a high-intensity fluorescence signal was observed in the entire lung up to 50h after tracheal injection of Cy5.5-APTnAChR-α1, whereas most of the fluorescence signal from a Cy5.5-labeled scrambled peptide washed out within 20h after injection. Taken together, these results indicate that the high-affinity peptide for nAChR-α1 identified here bound tightly to lung epithelium and thus exhibited a long residence time in this tissue, suggesting that the peptide could be used for pulmonary delivery of active pharmaceuticals.
authors.affiliation: School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Gwangju 500-712, Republic of Korea.
authors.forename: Seho
authors.initials: S
authors.lastname: Park
authors.affiliation: School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Gwangju 500-712, Republic of Korea.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: KAIST Institute for the BioCentury, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon 305-701, Republic of Korea. Electronic address: syjon@kaist.ac.kr.
authors.forename: Sangyong
authors.initials: S
authors.lastname: Jon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism*; D016503:Drug Delivery Systems; D008168:Lung / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011978:Receptors, Nicotinic / Q000378:metabolism*
chemical_list: C555576:CHRNA1 protein, mouse; D004337:Drug Carriers; D019151:Peptide Library; D010455:Peptides; D011978:Receptors, Nicotinic
keywords: Aptides; Nicotinic acetylcholine receptors; Phage display; Pulmonary delivery