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Yi JY, Ryu J, Jeong Y, Cho Y, Kim M, Jeon M, Park HH, Hwang NS, Jeong HJ, Sung C. One-step detection of procollagen type III N-terminal peptide as a fibrosis biomarker using fluorescent immunosensor (quenchbody). Anal Chim Acta 2024; 1317:342887. [PMID: 39030019 DOI: 10.1016/j.aca.2024.342887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/29/2024] [Accepted: 06/17/2024] [Indexed: 07/21/2024]
Abstract
BACKGROUND Procollagen type III N-terminal peptide (P-III-NP) is a fibrosis biomarker associated with liver and cardiac fibrosis. Despite the value of P-III-NP as a biomarker, its analysis currently relies on enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIA), which require more than 3 h. To facilitate early diagnosis and treatment through rapid biomarker testing, we developed a one-step immunoassay for P-III-NP using a quenchbody, which is a fluorescence-labeled immunosensor for immediate signal generation. RESULTS To create quenchbodies, the total mRNA of P-III-NP antibodies was extracted from early-developed hybridoma cells, and genes of variable regions were obtained through cDNA synthesis, inverse PCR, and sequencing. A single-chain variable fragment (scFv) with an N-terminal Cys-tag was expressed in E. coli Shuffle T7, resulting in a final yield of 9.8 mg L-1. The fluorescent dye was labeled on the Cys-tag of the anti-P-III-NP scFv using maleimide-thiol click chemistry, and the spacer arm lengths between the maleimide-fluorescent dyes were compared. Consequently, a TAMRA-C6-labeled quenchbody exhibited antigen-dependent fluorescence signals and demonstrated its ability to detect P-III-NP at concentrations as low as 0.46 ng mL-1 for buffer samples, 1.0 ng mL-1 for 2 % human serum samples. SIGNIFICANCE This one-step P-III-NP detection method provides both qualitative and quantitative outcomes within a concise 5-min timeframe. Furthermore, its application can be expanded using a 96-well platform and human serum, making it a high-throughput and sensitive method for testing fibrotic biomarkers.
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Affiliation(s)
- Joon-Yeop Yi
- Doping Control Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaewon Ryu
- Department of Biological and Environmental Science, Dongguk University, Goyang-si, Gyeonggi-do, 10326, Republic of Korea
| | - Yujin Jeong
- Doping Control Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Department of Bioengineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Yoeseph Cho
- Doping Control Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
| | - Minyoung Kim
- Doping Control Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Mijin Jeon
- Doping Control Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
| | - Hee Ho Park
- Department of Bioengineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Nathaniel S Hwang
- Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, 08826, Republic of Korea; School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea; Institute of Engineering Research, Seoul National University, Seoul, 08826, Republic of Korea; Bio-Max/N-Bio Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hee-Jin Jeong
- Department of Biological and Chemical Engineering, Hongik University, Sejong, 30016, Republic of Korea
| | - Changmin Sung
- Doping Control Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea.
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El Salamouni NS, Cater JH, Spenkelink LM, Yu H. Nanobody engineering: computational modelling and design for biomedical and therapeutic applications. FEBS Open Bio 2024. [PMID: 38898362 DOI: 10.1002/2211-5463.13850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 05/25/2024] [Accepted: 06/10/2024] [Indexed: 06/21/2024] Open
Abstract
Nanobodies, the smallest functional antibody fragment derived from camelid heavy-chain-only antibodies, have emerged as powerful tools for diverse biomedical applications. In this comprehensive review, we discuss the structural characteristics, functional properties, and computational approaches driving the design and optimisation of synthetic nanobodies. We explore their unique antigen-binding domains, highlighting the critical role of complementarity-determining regions in target recognition and specificity. This review further underscores the advantages of nanobodies over conventional antibodies from a biosynthesis perspective, including their small size, stability, and solubility, which make them ideal candidates for economical antigen capture in diagnostics, therapeutics, and biosensing. We discuss the recent advancements in computational methods for nanobody modelling, epitope prediction, and affinity maturation, shedding light on their intricate antigen-binding mechanisms and conformational dynamics. Finally, we examine a direct example of how computational design strategies were implemented for improving a nanobody-based immunosensor, known as a Quenchbody. Through combining experimental findings and computational insights, this review elucidates the transformative impact of nanobodies in biotechnology and biomedical research, offering a roadmap for future advancements and applications in healthcare and diagnostics.
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Affiliation(s)
- Nehad S El Salamouni
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Australia
| | - Jordan H Cater
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Australia
| | - Lisanne M Spenkelink
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Australia
| | - Haibo Yu
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Australia
- ARC Centre of Excellence in Quantum Biotechnology, University of Wollongong, Australia
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3
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Fang Z, Zhang H, Guo J, Guo J. Overview of therapeutic drug monitoring and clinical practice. Talanta 2024; 266:124996. [PMID: 37562225 DOI: 10.1016/j.talanta.2023.124996] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/29/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023]
Abstract
With the rapid development of clinical pharmacy in China, therapeutic drug monitoring (TDM) has become an essential tool for guiding rational clinical drug use and is widely concerned. TDM is a tool that combines pharmacokinetic and pharmacodynamic knowledge to optimize personalized drug therapy, which can improve treatment outcomes, reduce drug-drug toxicity, and avoid the risk of developing drug resistance. To effectively implement TDM, accurate and sophisticated analytical methods are required. By researching the literature published in recent years, we summarize the types of commonly monitored drugs, therapeutic windows, and clinical assays and track the trends and hot spots of therapeutic drug monitoring. The purpose is to provide guidelines for clinical blood drug concentration monitoring, to implement individualized drug delivery programs better, to ensure the rational use of drugs for patients, and to provide a reference for the group to carry out related topics in the future.
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Affiliation(s)
- Zijun Fang
- University of Southwest Petroleum University, College of Mechanical and Electrical Engineering, Chengdu, China
| | - He Zhang
- University of Southwest Petroleum University, College of Mechanical and Electrical Engineering, Chengdu, China
| | - Jiuchuan Guo
- University of Electronic Science and Technology of China, Chengdu, China.
| | - Jinhong Guo
- School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, China.
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Sasamoto K, Yasuda T, Zhu B, Ueda H, Kitaguchi T. Efficient and rapid linker optimization with heterodimeric coiled coils improves the response of fluorescent biosensors comprising antibodies and protein M. Analyst 2023; 148:5843-5850. [PMID: 37941425 DOI: 10.1039/d3an01499a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
We developed a coiled Q-probe (CQ-probe), a fluorescent probe containing a coiled-coil peptide pair E4/K4, to convert antibodies into biosensors for homogeneous immunoassays. This probe consists of an antibody-binding protein, protein M (PM) with the E4 peptide and the K4 peptide with a fluorescent dye. Compared to PM Q-probes, which are generated by modifying the C-terminus of PM with a fluorescent dye, CQ-probe variants with various linkers are easy to prepare and therefore enable the establishment of biosensors with a significant fluorescence response by localizing the fluorescent dye at the optimal position for quenching and antigen-dependent release. The fluorescence changes of biosensors converted from anti-BGP, anti-cortisol, and anti-testosterone antibodies using the rhodamine 6G (or TAMRA)-labeled CQ-probe upon antigen addition were 13 (or 2.6), 9.7 (or 1.5), and 2.1 (or 1.2) times larger than that of the biosensors converted using the PM Q-probe. Furthermore, the CQ-probe converted anti-digoxin IgG into a functional biosensor, whereas the PM Q-probe/antibody complex showed an insufficient response. This technology exhibits a promising capacity to convert antibodies into high-response biosensors, which are expected to be applied in a wide range of fields, including clinical diagnosis, environmental surveys, food analysis, and biological research.
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Affiliation(s)
- Kana Sasamoto
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Takanobu Yasuda
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
| | - Bo Zhu
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
| | - Hiroshi Ueda
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
| | - Tetsuya Kitaguchi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
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Jung J, Jeong Y, Xu Y, Yi J, Kim M, Jeong HJ, Shin SH, Yang YH, Son J, Sung C. Production and engineering of nanobody-based quenchbody sensors for detecting recombinant human growth hormone and its isoforms. Drug Test Anal 2023; 15:1439-1448. [PMID: 37667448 DOI: 10.1002/dta.3562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 09/06/2023]
Abstract
Due to athletes' misuse of recombinant human growth hormone (rhGH) for performance improvement, the World Anti-Doping Agency has designated rhGH as a prohibited substance. This study focuses on the development and improvement of a simple and fast rhGH detection method using a fluorescence-incorporated antibody sensor "Quenchbody (Q-body)" that activates upon antigen binding. Camelid-derived nanobodies were used to produce stable Q-bodies that withstand high temperatures and pH levels. Notably, pituitary human growth hormone (phGH) comprises two major isoforms, namely 22 and 20 kDa GH, which exist in a specific ratio, and the rhGH variant shares the same sequence as the 22 kDa GH isoform. Therefore, we aimed to discriminate rhGH abuse by analyzing its specific isoform ratio. Two nanobodies, NbPit (recognizing phGH) and NbRec (preferentially recognizing 22 kDa rhGH), were used to develop the Q-bodies. Nanobody production in Escherichia coli involved the utilization of a vector containing 6xHis-tag, and Q-bodies were obtained using a maleimide-thiol reaction between the N-terminal of the cysteine tag and a fluorescent dye. The addition of tryptophan residue through antibody engineering resulted in increased fluorescence intensity (FI) (from 2.58-fold to 3.04-fold). The limit of detection (LOD) was determined using a fluorescence response, with TAMRA-labeled NbRec successfully detecting 6.38 ng/ml of 22 kDa rhGH while unable to detect 20 kDa GH. However, ATTO520-labeled NbPit detected 7.00 ng/ml of 20 kDa GH and 2.20 ng/ml 22 kDa rhGH. Q-bodies successfully detected changes in the GH concentration ratio from 10 to 40 ng/ml in human serum within 10 min without requiring specialized equipment and kits. Overall, these findings have potential applications in the field of anti-doping measures and can contribute to improved monitoring and enforcement of rhGH misuse, ultimately enhancing fairness and integrity in competitive sports.
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Affiliation(s)
- Jaehoon Jung
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, Republic of Korea
| | - Yujin Jeong
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Department of Bioengineering, Hanyang University, Seoul, Republic of Korea
| | - Yinglan Xu
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Joonyeop Yi
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, Republic of Korea
| | - Minyoung Kim
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Hee-Jin Jeong
- Department of Biological and Chemical Engineering, Hongik University Sejong-ro 2639, Sejong, Republic of Korea
| | - Sang Hoon Shin
- Department of Surgery, Chonnam National University Hwasun Hospital, Hwasun, Republic of Korea
| | - Yung-Hun Yang
- Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, Republic of Korea
| | - Junghyun Son
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Changmin Sung
- Doping Control Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
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Jeong HJ. Quenchbodies That Enable One-Pot Detection of Antigens: A Structural Perspective. Bioengineering (Basel) 2023; 10:1262. [PMID: 38002387 PMCID: PMC10669387 DOI: 10.3390/bioengineering10111262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 10/21/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Quenchbody (Q-body) is a unique, reagentless, fluorescent antibody whose fluorescent intensity increases in an antigen-concentration-dependent manner. Q-body-based homogeneous immunoassay is superior to conventional immunoassays as it does not require multiple immobilization, reaction, and washing steps. In fact, simply mixing the Q-body and the sample containing the antigen enables the detection of the target antigen. To date, various Q-bodies have been developed to detect biomarkers of interest, including haptens, peptides, proteins, and cells. This review sought to describe the principle of Q-body-based immunoassay and the use of Q-body for various immunoassays. In particular, the Q-bodies were classified from a structural perspective to provide useful information for designing Q-bodies with an appropriate objective.
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Affiliation(s)
- Hee-Jin Jeong
- Department of Biological and Chemical Engineering, Hongik University, Sejong-si 30016, Republic of Korea
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7
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Liang YF, Li JD, Fang RY, Xu ZL, Luo L, Chen ZJ, Yang JY, Shen YD, Ueda H, Hammock B, Wang H. Design of an Antigen-Triggered Nanobody-Based Fluorescence Probe for PET Immunoassay to Detect Quinalphos in Food Samples. Anal Chem 2023; 95:12321-12328. [PMID: 37527540 DOI: 10.1021/acs.analchem.3c01696] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Photoinduced electron-transfer (PET) immunoassay based on a fluorescence site-specifically labeled nanobody, also called mini Quenchbody (Q-body), exhibits extraordinary sensitivity and saves much time in the homogeneous noncompetitive mode and is therefore regarded as a valuable method. However, limited by the efficiency of both quenching and dequenching of the fluorescence signal before and after antigen binding associated with the PET principle, not all original nanobodies can be used as candidates for mini Q-bodies. Herein, with the anti-quinalphos nanobody 11A (Nb-11A) as the model, we, for the first time, adopt a strategy by combining X-ray structural analysis with site-directed mutagenesis to design and produce a mutant Nb-R29W, and then successfully generate a mini Q-body by labeling with ATTO520 fluorescein. Based on this, a novel PET immunoassay is established, which exhibits a limit of detection of 0.007 μg/mL with a detection time of only 15 min, 25-fold improved sensitivity, and faster by 5-fold compared to the competitive immunoassay. Meanwhile, the recovery test of vegetable samples and validation by the standard ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) both demonstrated that the established PET immunoassay is a novel, sensitive, and accurate detection method for quinalphos. Ultimately, the findings of this work will provide valuable insights into the development of triggered PET fluorescence probes by using existing antibody resources.
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Affiliation(s)
- Yi-Fan Liang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Jia-Dong Li
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Ru-Yu Fang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Zhen-Lin Xu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Lin Luo
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Zi-Jian Chen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Jin-Yi Yang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Yu-Dong Shen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Hiroshi Ueda
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Bruce Hammock
- Department of Entomology and Nematology, UCD Comprehensive Cancer Center, University of California Davis, Davis, California 95616, United States
| | - Hong Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
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Immunosensor for realtime monitoring of the expression of recombinant proteins during bioprocess. Anal Biochem 2023; 665:115069. [PMID: 36716945 DOI: 10.1016/j.ab.2023.115069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/16/2023] [Accepted: 01/26/2023] [Indexed: 01/30/2023]
Abstract
Recombinant protein expression and purification are crucial in modern life sciences research. A fluorescent immunosensor termed Quenchbody (Q-body) was developed for real-time monitoring of FLAG-fused protein expression. Detection results showed that the limit of detection of the 3 × FLAG peptide detected by the TAMRA-labeled anti-FLAG Q-body was as low as 3.1 nM, with a half-maximal effective concentration of 21.4 nM. Furthermore, the anti-FLAG Q-body was used for detecting different proteins fused with a FLAG-tag at the N- or C-terminal. Subsequently, the constructed Q-body was used to monitor the real-time fermentation process of single-strand DNA-binding protein in Escherichia coli. Unlike previously reported Q-bodies that widely used Fab or scFv, the present study used a full-length anti-FLAG IgG for the first time. Owing to its excellent detection speed and sensitivity, the FLAG Q-body immunosensor has the potential to quantify and monitor target recombinant proteins in multiple biological processes in real-time.
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Development of a Spacer-optimized Quenchbody against Tumor Necrosis Factor Alpha. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-022-0088-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Qiao X, Qu L, Guo Y, Hoshino T. Secondary Structure and Conformational Stability of the Antigen Residues Making Contact with Antibodies. J Phys Chem B 2021; 125:11374-11385. [PMID: 34615354 DOI: 10.1021/acs.jpcb.1c05997] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Antibodies are crucial biomolecules that bring high therapeutic efficacy in medicine and accurate molecular detection in diagnosis. Many studies have been devoted to analyzing the antigen-antibody interaction from the importance of understanding the antibody recognition mechanism. However, most of the previous studies examined the characteristic of the antibody for interaction. It is also informative to clarify the significant antigen residues contributing to the binding. To characterize the molecular interaction of antigens, we computationally analyzed 350 antigen-antibody complex structures by molecular mechanics (MM) calculations and molecular dynamics (MD) simulations. Based on the MM calculations, the antigen residues contributing to the binding were extracted from all the 350 complexes. The extracted residues are located at the antigen-antibody interface and are responsible for making contact with the antibody. The appearances of the charged polar residues, Asp, Glu, Arg, and Lys, were noticeably large. In contrast, the populations of the hydrophobic residues, Leu, Val, and Ala, were relatively low. The appearance frequencies of the other amino acid residues were almost close to the abundance of general proteins of eukaryotes. The binding score indicated that the hydrophilic interaction was dominant at the antigen-antibody contact instead of the hydrophobic one. The positively charged residues, Arg and Lys, remarkably contributed to the binding compared to the negatively charged ones, Asp and Glu. Considerable contributions were also observed for the noncharged polar residues, Asn and Gln. The analysis of the secondary structures of the extracted antigen residues suggested that there was no marked difference in recognition by antibodies among helix, sheet, turn, and coil. A long helix of the antigen sometimes made contact with antibody complementarity-determining regions, and a large sheet also frequently covered the antibody heavy and light chains. The turn structure was the most popularly observed at the contact with antibody among 350 complexes. Three typical complexes were picked up for each of the four secondary structures. MD simulations were performed to examine the stability of the interfacial structures of the antigens for these 12 complex models. The alterations of secondary structures were monitored through the simulations. The structural fluctuations of the contact residues were low compared with the other domains of antigen molecules. No drastic conversion was observed for every model during the 100 ns simulation. The motions of the interfacial antigen residues were small compared to the other residues on the protein surface. Therefore, diverse molecular conformations are possible for antibody recognition as long as the target areas are polar, nonflexible, and protruding on the protein surface.
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Affiliation(s)
- Xinyue Qiao
- Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Liang Qu
- Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Yan Guo
- Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Tyuji Hoshino
- Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
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Dong J, Ueda H. Recent Advances in Quenchbody, a Fluorescent Immunosensor. SENSORS 2021; 21:s21041223. [PMID: 33572319 PMCID: PMC7916128 DOI: 10.3390/s21041223] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/27/2021] [Accepted: 02/06/2021] [Indexed: 12/29/2022]
Abstract
The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.
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Affiliation(s)
- Jinhua Dong
- Tokyo Tech World Research Hub Initiative (WRHI), Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan;
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Hiroshi Ueda
- Tokyo Tech World Research Hub Initiative (WRHI), Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan;
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Correspondence: ; Tel.: +81-45-924-5256
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Inoue A, Ohmuro-Matsuyama Y, Kitaguchi T, Ueda H. Creation of a Nanobody-Based Fluorescent Immunosensor Mini Q-body for Rapid Signal-On Detection of Small Hapten Methotrexate. ACS Sens 2020; 5:3457-3464. [PMID: 33169966 DOI: 10.1021/acssensors.0c01404] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
"Quenchbody (Q-body)" is a quench-based fluorescent biosensor labeled with a fluorescent dye near the antigen-binding site of an antibody. Q-bodies can detect a range of target molecules quickly by simply mixing with a sample. However, the development of Q-bodies using VHH-nanobodies derived from camelid heavy-chain antibodies has not been reported despite their favorable characteristics. Here, we report a "mini Q-body" that can detect the chemotherapy agent methotrexate (MTX) by using anti-MTX nanobody. Three kinds of constructs each encoding an N-terminal Cys-tag and anti-MTX VHH gene with a different length of linker (GGGS)n (n = 0, 2, and 4) between them were prepared followed by the expression in Escherichia coli and labeling with several dye maleimides. When the fluorescence intensities in the presence of varied MTX concentrations were measured, TAMRA-labeled nanobodies showed a higher response than ATTO520- or R6G-labeled ones. Especially, TAMRA C6-labeled mini Q-body with no linker showed the highest response of ∼6-fold and a low detection limit of 0.56 nM. When each Trp residue in the mini Q-body was mutated to address the quenching mechanism, the major role of Trp34 at CDR1 in quenching was revealed. Furthermore, the mini Q-body could detect MTX in 50% human serum with a low detection limit of 1.72 nM, showing its applicability to therapeutic drug monitoring. This study is expected to become the basis of the construction of highly responsive mini Q-bodies for sensitive detection of many molecules from small haptens to larger proteins, which will lead to broader applications such as point-of-care tests.
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Affiliation(s)
- Akihito Inoue
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Yokohama, Kanagawa 226-8503, Japan
| | - Yuki Ohmuro-Matsuyama
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Yokohama, Kanagawa 226-8503, Japan
| | - Tetsuya Kitaguchi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Yokohama, Kanagawa 226-8503, Japan
| | - Hiroshi Ueda
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Yokohama, Kanagawa 226-8503, Japan
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Dong J, Miyake C, Yasuda T, Oyama H, Morita I, Tsukahara T, Takahashi M, Jeong HJ, Kitaguchi T, Kobayashi N, Ueda H. PM Q-probe: A fluorescent binding protein that converts many antibodies to a fluorescent biosensor. Biosens Bioelectron 2020; 165:112425. [DOI: 10.1016/j.bios.2020.112425] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/22/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022]
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