title: Generation of Internal-Image Functional Aptamers of Okadaic Acid via Magnetic-Bead SELEX.
abstract: Okadaic acid (OA) is produced by Dinophysis and Prorocentrum dinoflagellates and primarily accumulates in bivalves, and this toxin has harmful effects on consumers and operators. In this work, we first report the use of aptamers as novel non-toxic probes capable of binding to a monoclonal antibody against OA (OA-mAb). Aptamers that mimic the OA toxin with high affinity and selectivity were generated by the magnetic bead-assisted systematic evolution of ligands by exponential enrichment (SELEX) strategy. After 12 selection rounds, cloning, sequencing and enzyme-linked immunosorbent assay (ELISA) analysis, four candidate aptamers (O24, O31, O39, O40) were selected that showed high affinity and specificity for OA-mAb. The affinity constants of O24, O31, O39 and O40 were 8.3 × 10⁸ M(-1), 1.47 × 10⁸ M(-1), 1.23 × 10⁸ M(-1) and 1.05 × 10⁸ M(-1), respectively. Indirect competitive ELISA was employed to determine the internal-image function of the aptamers. The results reveal that O31 has a similar competitive function as free OA toxin, whereas the other three aptamers did not bear the necessary internal-image function. Based on the derivation of the curvilinear equation for OA/O31, the equation that defined the relationship between the OA toxin content and O31 was Y = 2.185X - 1.78. The IC50 of O31 was 3.39 ng·mL(-1), which was close to the value predicted by the OA ELISA (IC50 = 4.4 ng·mL(-1)); the IC10 was 0.33 ng·mL(-1). The above data provides strong evidence that internal-image functional aptamers could be applicable as novel probes in a non-toxic assay.
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. sara851109@hotmail.com.|Institute of Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Jilin, Changchun 130062, China. sara851109@hotmail.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Lin
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. zsliu1959@163.com.
authors.forename: Zeng-Shan
authors.initials: ZS
authors.lastname: Liu
authors.affiliation: Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Science, Jilin University, Changchun 130062, China. wang_dong_xu@163.com.
authors.forename: Dong-Xu
authors.initials: DX
authors.lastname: Wang
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. justme20150701@163.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. hupan84@163.com.
authors.forename: Pan
authors.initials: P
authors.lastname: Hu
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. gongsheng1105@126.com.
authors.forename: Sheng
authors.initials: S
authors.lastname: Gong
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. l_ys92305@163.com.
authors.forename: Yan-Song
authors.initials: YS
authors.lastname: Li
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. ccjlucornell@sina.com.
authors.forename: Cheng
authors.initials: C
authors.lastname: Cui
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. Wuzongcheng66@126.com.
authors.forename: Zong-Cheng
authors.initials: ZC
authors.lastname: Wu
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. gy497367360@sina.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. zhouyurunye@sina.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. renhl@jlu.edu.cn.
authors.forename: Hong-Lin
authors.initials: HL
authors.lastname: Ren
authors.affiliation: Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China. lushiying1129@163.com.
authors.forename: Shi-Ying
authors.initials: SY
authors.lastname: Lu
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D052157:Aptamers, Nucleotide / Q000276:immunology / Q000378:metabolism*; D004141:Dinoflagellida / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D020128:Inhibitory Concentration 50; D019319:Okadaic Acid / Q000276:immunology / Q000378:metabolism*; D052156:SELEX Aptamer Technique / Q000379:methods*
chemical_list: D000911:Antibodies, Monoclonal; D052157:Aptamers, Nucleotide; D019319:Okadaic Acid
keywords: SELEX; internal-image function; okadaic acid