title: Selection and identification of single-domain antibody fragment against capsid protein of porcine circovirus type 2 (PCV2) from C. bactrianus.
abstract: Single-domain variable heavy chain (VHH) antibody fragments are derived from heavy-chain antibodies of Camelids. Their comparatively small size, solubility, high affinity and specificity to the targets antigen make them suitable for many biotechnological applications. In this study, a VHH library was constructed from porcine circovirus type 2 (PCV2) vaccine immunized C. bactrianus and three VHH fragments specific to the capsid protein of PCV2 (PCV2 Cap) were selected and characterized. The selected VHH clones (VHH-c1/c3/c4) were stably expressed as soluble protein in E. coli, and were specific to PCV2 Cap except VHH-c3 which shows binding activity with both PCV1 and PCV2 Cap by ELISA. All the VHH-cs show high association rate constant and dissociation rate constant, which was 1.84 × 10(5)M(-1)s(-1), 9.00 × 10(-3)s(-1) for VHH-c1, 5.49 × 10(4)M(-1)s(-1), 9.91 × 10(-3)s(-1) and 1.46 × 10(5)M(-1)s(-1), 1.18 × 10(-3)s(-1) for VHH-c3 and VHH-c4 assessed by surface plasmon resonance (SPR). Additionally, the selected three VHH-cs can bind to different epitopes of PCV2 Cap that was determined by additive ELISA. Our study confirmed that VHHs with high affinity and specificity to PCV2 Cap can be selected from an immune VHH library, and have the potential application for effective and fast diagnostic development of PCV2.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China.
authors.forename: Shunli
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China.
authors.forename: Youjun
authors.initials: Y
authors.lastname: Shang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China. Electronic address: yinshuanghuikangri@163.com.
authors.forename: Shuanghui
authors.initials: S
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China.
authors.forename: Hong
authors.initials: H
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China.
authors.forename: Shiqi
authors.initials: S
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth, Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Yanchangbu, Lanzhou 730046, Gansu China. Electronic address: hnxiangtao@hotmail.com.
authors.forename: Xiangtao
authors.initials: X
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000915:Antibody Affinity; D000956:Antigens, Viral; D002162:Camelus; D036022:Capsid Proteins / Q000276:immunology*; D018173:Circoviridae Infections / Q000097:blood / Q000276:immunology / Q000662:veterinary*; D017925:Circovirus / Q000145:classification* / Q000276:immunology / Q000378:metabolism; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay; D008297:Male; D017434:Protein Structure, Tertiary; D061905:Single-Domain Antibodies / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; D061905:Single-Domain Antibodies; D014765:Viral Vaccines
keywords: C. bactrainus; PCV2; Single-domain antibody