PMID- 32498825
OWN - NLM
STAT- MEDLINE
DCOM- 20210125
LR  - 20210125
IS  - 1873-3573 (Electronic)
IS  - 0039-9140 (Linking)
VI  - 217
DP  - 2020 Sep 1
TI  - Directing a rational design of aptamer-based fluorescence anisotropy assay for 
      sensitive detection of immunoglobulin E by site-specific binding study.
PG  - 121018
LID - S0039-9140(20)30309-X [pii]
LID - 10.1016/j.talanta.2020.121018 [doi]
AB  - Mapping aptamer-protein interactions is important for characterization and 
      applications of aptamers against proteins. We describe here probing affinity 
      interactions between aptamer and immunoglobulin E (IgE) with a fluorescence 
      anisotropy (FA) approach using a series of aptamer probes having single 
      fluorescein (FAM) label at individual nucleotide (A, C, T). Studies of binding 
      between IgE and aptamer probes revealed several possible close-contact sites, 
      e.g., T9, T10, T11, T13, C15, and T17 of a 37-nt aptamer with a stem-loop 
      secondary structure. FAM labeling on these sites resulted in much higher FA 
      values (higher than 0.230 for T10, T11, T13 and C15) of aptamer-IgE complexes 
      than the distant sites (e.g., terminals) of aptamer probably because the bound 
      IgE close to these sites significantly restricted local rotation of FAM. 
      Close-contact site labeled aptamer probes with high affinity allowed to develop a 
      more sensitive FA assay for IgE than distant site labeled aptamers. The FA assay 
      using T10-labeled aptamer with a dissociation constant (K(d)) about 0.8 nM 
      enabled selective detection of IgE at 20 pM and large FA increase upon IgE 
      addition. We also found A12, C14, A25, and T27 were important for IgE-aptamer 
      binding as FAM labeling at these sites significantly reduced aptamer affinity. FA 
      study showed the loop region of this stem-loop aptamer was crucial for affinity 
      binding, and IgE bound to the loop. This FA method will be helpful for 
      understanding aptamer-protein binding and making a rational design of aptamer 
      affinity assays for proteins.
CI  - Copyright (c) 2020 Elsevier B.V. All rights reserved.
FAU - Zhao, Qiang
AU  - Zhao Q
AD  - State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research 
      Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 
      100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China. 
      Electronic address: qiangzhao@rcees.ac.cn.
FAU - Bai, Yunlong
AU  - Bai Y
AD  - State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research 
      Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 
      100085, China.
FAU - Wang, Hailin
AU  - Wang H
AD  - State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research 
      Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 
      100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
LA  - eng
PT  - Journal Article
DEP - 20200413
PL  - Netherlands
TA  - Talanta
JT  - Talanta
JID - 2984816R
RN  - 0 (Aptamers, Nucleotide)
RN  - 0 (Fluorescent Dyes)
RN  - 37341-29-0 (Immunoglobulin E)
SB  - IM
MH  - Aptamers, Nucleotide/*chemistry
MH  - Binding Sites
MH  - Equipment Design
MH  - *Fluorescence Polarization
MH  - Fluorescent Dyes/*chemistry
MH  - Humans
MH  - Immunoglobulin E/*blood
OTO - NOTNLM
OT  - Affinity binding
OT  - Binding sites
OT  - Fluorescence anisotropy
OT  - Fluorescence polarization
OT  - Molecular interactions
OT  - Sensors
COIS- Declaration of competing interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2020/06/06 06:00
MHDA- 2021/01/26 06:00
CRDT- 2020/06/06 06:00
PHST- 2020/01/28 00:00 [received]
PHST- 2020/04/06 00:00 [revised]
PHST- 2020/04/06 00:00 [accepted]
PHST- 2020/06/06 06:00 [entrez]
PHST- 2020/06/06 06:00 [pubmed]
PHST- 2021/01/26 06:00 [medline]
AID - S0039-9140(20)30309-X [pii]
AID - 10.1016/j.talanta.2020.121018 [doi]
PST - ppublish
SO  - Talanta. 2020 Sep 1;217:121018. doi: 10.1016/j.talanta.2020.121018. Epub 2020 Apr 
      13.