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Zhou W, Xiang Y, Yang J, Chen T. Metal ion-complexed DNA probe coupled with CRISPR/Cas12a amplification and AuNPs for sensitive colorimetric assay of metallothionein in fish. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 321:124682. [PMID: 38936209 DOI: 10.1016/j.saa.2024.124682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 05/30/2024] [Accepted: 06/18/2024] [Indexed: 06/29/2024]
Abstract
The accurate and sensitive detection of metallothionein (MT) is of great significance in the fields of biomedical, toxicological and environmental sciences. In this work, based on the high affinity interaction between MT and the heavy metal ions of Hg2+ and the significant signal amplification capability of Cas12a/crRNA enzyme as well, we report a simple and highly sensitive method for visual detection of MT, a biomarker in fish for heavy metal ion-induced water bio-pollution. The target MT molecules bind Hg2+ in the Hg2+- complexed hairpin DNA probes to unfold the hairpin structure into ssDNAs, which hybridize with the partial dsDNA duplexes via strand displacement to yield specific sequence-containing dsDNAs. Cas12a/crRNA recognizes these specific sequences to activate its enzyme activity to cyclically cleave the ssDNA linkers in the blue colored gold nanoparticle aggregates to transit their color into red to realize visual detection of MT. Owing to the signal amplification by Cas12a/crRNA, as low as 25 nM of MT can be visually detected with naked eye. In addition, our colorimetric detection method has high selectivity for MT against other interference proteins and can detect MT in the livers and kidneys of crucian carps bought from a local supermarket. Moreover, the developed assay overcomes the limitations of conventional MT detection methods in terms of complexity, high cost and low sensitivity and can therefore offer new methods for monitoring water bio-pollutions.
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Affiliation(s)
- Wenjiao Zhou
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, PR China.
| | - Yu Xiang
- Chongqing Yucai Secondary School, Chongqing 400050, PR China
| | - Jirong Yang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Tiantian Chen
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, PR China
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Yang R, Roshani D, Gao B, Li P, Shang N. Metallothionein: A Comprehensive Review of Its Classification, Structure, Biological Functions, and Applications. Antioxidants (Basel) 2024; 13:825. [PMID: 39061894 PMCID: PMC11273490 DOI: 10.3390/antiox13070825] [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: 05/27/2024] [Revised: 06/24/2024] [Accepted: 06/26/2024] [Indexed: 07/28/2024] Open
Abstract
Metallothionein is a cysteine-rich protein with a high metal content that is widely found in nature. In addition to heavy metal detoxification, metallothionein is well known as a potent antioxidant. The high sulfhydryl content of metallothionein confers excellent antioxidant activity, enabling it to effectively scavenge free radicals and mitigate oxidative stress damage. In addition, metallothionein can play a neuroprotective role by alleviating oxidative damage in nerve cells, have an anticancer effect by enhancing the ability of normal cells to resist unfavorable conditions through its antioxidant function, and reduce inflammation by scavenging reactive oxygen species. Due to its diverse biological functions, metallothionein has a broad potential for application in alleviating environmental heavy metal pollution, predicting and diagnosing diseases, and developing skin care products and health foods. This review summarizes the recent advances in the classification, structure, biological functions, and applications of metallothionein, focusing on its powerful antioxidant effects and related functions.
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Affiliation(s)
- Ruoqiu Yang
- Key Laboratory of Precision Nutrition and Food Quality, College of Food Science and Nutritional Engineering, China Agricultural University, No, 17 Qinghua East Road, Haidian District, Beijing 100083, China; (R.Y.); (B.G.)
| | - Dumila Roshani
- College of Engineering, China Agricultural University, No, 17 Qinghua East Road, Haidian District, Beijing 100083, China;
| | - Boya Gao
- Key Laboratory of Precision Nutrition and Food Quality, College of Food Science and Nutritional Engineering, China Agricultural University, No, 17 Qinghua East Road, Haidian District, Beijing 100083, China; (R.Y.); (B.G.)
| | - Pinglan Li
- Key Laboratory of Precision Nutrition and Food Quality, College of Food Science and Nutritional Engineering, China Agricultural University, No, 17 Qinghua East Road, Haidian District, Beijing 100083, China; (R.Y.); (B.G.)
| | - Nan Shang
- College of Engineering, China Agricultural University, No, 17 Qinghua East Road, Haidian District, Beijing 100083, China;
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Structural Characterization and In Vitro Antioxidant Activity of Metallothionein from Oratosquilla oratoria. Molecules 2022; 27:molecules27072320. [PMID: 35408719 PMCID: PMC9000697 DOI: 10.3390/molecules27072320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 02/01/2023] Open
Abstract
We report here the purification of a novel metal-binding protein from Oratosquilla oratoria (O. oratoria MT-1) by gel and ion-exchange chromatography. SDS-PAGE and MALDI-TOF analyses demonstrated that isolated O. oratoria MT-1 was of high purity with a molecular weight of 12.4 kDa. The fluorescence response to SBD-F derivatives revealed that O. oratoria MT-1 contained a large number of sulfhydryl groups, which is a general property of metallothioneins. Zn and Cu metal stoichiometries for O. oratoria MT-1 were 3.97:1 and 0.55:1, respectively. The proportion of cysteine (Cys) residues in the amino acid composition was 32.69%, and aromatic amino acids were absent. The peptide sequence coverage with Macrobrachium rosenbergii calmodulin (accession AOA3S8FSK5) was 60%. Infrared spectroscopy of O. oratoria MT-1 revealed two obvious peaks at absorption frequencies for the amide I band and the amide II band. CD spectra revealed that the secondary structure was mainly composed of random coil (57.6%) and β-sheet (39.9%). An evaluation of in vitro antioxidant activity revealed that isolated O. oratoria MT-1 has strong reducing activities, exhibiting scavenging rates for DPPH and OH of 77.8% and 75.8%, respectively (IC50 values 0.57 mg/mL and 1.1 mg/mL). O. oratoria MT-1 may be used as a functional additive in cosmetics, health foods, and medical products, as well as a reference material for quantitative analysis of metallothionein in such products.
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O'Callaghan I, Fitzpatrick D, Sullivan T. Thiophilicity is a determinant of bioaccumulation in benthic fauna. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 294:118641. [PMID: 34890745 DOI: 10.1016/j.envpol.2021.118641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/09/2021] [Accepted: 12/03/2021] [Indexed: 06/13/2023]
Abstract
Aquatic contamination can settle into sediments, where it complexes with organic matter and becomes bioavailable. The resulting bioaccumulation of these contaminants by benthic fauna poses a serious threat due to the potential for trophic transfer. This paper offers an insight into the heterogenous accumulation behavior of different elements, and the consequences for ecological risk. In this study, we present field quantification of sediment-associated bioaccumulation factors (BAFS) in freshwater benthic macroinvertebrates. 17 elements were quantified using ICP-MS in sediment and Asellus aquaticus and Gammarus sp. samples. Previously published reports of contaminant concentrations in freshwater and marine sediments and benthic fauna were likewise analyzed to provide a complementary picture of bioaccumulation across contaminants and taxa. We demonstrate that the BAFS correlates strongly with the thiophilicity of the elemental contaminants, as defined by (Kepp, 2016), for all strata examined. These findings support the hypothesis that thiol-mediated processes, such as that of metallothionein, play a larger role in bioaccumulation than typically afforded. In conclusion, we demonstrate the potential for the thiophilic scale to act as a predictor of accumulation potential.
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Affiliation(s)
- Irene O'Callaghan
- School of Biological, Earth & Environmental Sciences, University College Cork, Ireland; School of Chemistry, University College Cork, Ireland.
| | | | - Timothy Sullivan
- School of Biological, Earth & Environmental Sciences, University College Cork, Ireland; Environmental Research Institute, University College Cork, Ireland
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Li X, Ren Z, Crabbe MJC, Wang L, Ma W. Genetic modifications of metallothionein enhance the tolerance and bioaccumulation of heavy metals in Escherichia coli. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 222:112512. [PMID: 34271502 DOI: 10.1016/j.ecoenv.2021.112512] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Metallothioneins (MTs) are low molecular weight cysteine-rich proteins that bind to metals. Owing to their high cysteine (Cys) content, MTs are effective mediators of heavy metal detoxification. To enhance the heavy metal binding ability of MT from the freshwater crab Sinopotamon henanense (ShMT), sequence-based multiple sequence alignment (MSA) and structure-based molecular docking simulation (MDS) were conducted in order to identify amino acid residues that could be mutated to bolster such metal-binding activity. Site-directed mutagenesis was then used to modify the primary structure of ShMT, and the recombinant proteins were further enhanced using the SUMO fusion expression system to yield SUMO-ShMT1, SUMO-ShMT2, and SUMO-ShMT3 harboring one-, two-, and three- point mutations, respectively. The resultant modified proteins were primarily expressed in a soluble form and exhibited the ability to readily bind to heavy metals. Importantly, these modified proteins exhibited significantly enhanced heavy metal binding capacities, and they improved Cd2+, Cu2+ and Zn2+ tolerance and bioaccumulation in Escherichia coli (E. coli) in a manner dependent upon the number of introduced point mutations (SUMO-ShMT3 > SUMO-ShMT2 > SUMO-ShMT1 > SUMO-ShMT > control). Indeed, E. coli cells harboring the pET28a-SUMO-ShMT3 expression vector exhibited maximal Cd2+, Cu2+, and Zn2+ bioaccumulation that was increased by 1.86 ± 0.02-, 1.71 ± 0.03-, and 2.13 ± 0.02-fold relative to that in E. coli harboring the pET28a-SUMO-ShMT vector. The present study offers a basis for the preparation of genetically engineered bacteria that are better able to bioaccumulate and tolerate heavy metals, thus providing a foundation for biological heavy metal water pollution treatment.
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Affiliation(s)
- Xuefen Li
- School of Life Science, Shanxi University, Taiyuan 030006, PR China
| | - Zhumei Ren
- School of Life Science, Shanxi University, Taiyuan 030006, PR China
| | - M James C Crabbe
- School of Life Science, Shanxi University, Taiyuan 030006, PR China; Wolfson College, University of Oxford, Oxford OX2 6UD, UK; Institute of Biomedical and Environmental Science & Technology, School of Life Sciences, Faculty of Creative Arts, Technologies and Science, University of Bedfordshire, University Square, Luton LU1 3JU, UK
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan 030006, PR China
| | - Wenli Ma
- School of Life Science, Shanxi University, Taiyuan 030006, PR China.
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Xuan R, Wu H, Li Y, Wei B, Wang L. Comparative responses of Sinopotamon henanense to acute and sub-chronic Cd exposure. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:35038-35050. [PMID: 33665691 DOI: 10.1007/s11356-021-13230-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Studies on the freshwater crab Sinopotamon henanense have shown that acute and sub-chronic Cd2+ exposure induced differential alterations in the respiratory physiology and gill morphology. To elucidate Cd2+ toxicity under these two exposure conditions, crabs were acutely exposed to 7.14, 14.28, and 28.55 mg/L Cd2+ for 96 h and sub-chronically exposed to 0.71, 1.43, and 2.86 mg/L Cd2+ for 3 weeks. The Cd2+ accumulation, total metallothionein (MT), superoxide dismutase, and malondialdehyde (MDA) contents in the gill tissues were detected. Moreover, the glucose-6-phosphate dehydrogenase (G6PDH) activity, NADPH content, reduced glutathione (GSH), oxidized glutathione (GSSG), and GSH/GSSG ratio in the hepatopancreas were determined. The morphology of the X-organ-sinus gland complex was also observed. The results showed that sub-chronical Cd2+ exposure induced lower MT content and higher MDA level in the gills than in the acute exposure. In the hepatopancreas, acute Cd2+ exposure decreased the pentose phosphate pathway activity and NADPH content; however, an increased G6PDH activity and NADPH content were detected in sub-chronic Cd2+ exposure (2.86 mg/L). Morphological changes occurred in the sinus gland in crabs exposed to 2.86 mg/L Cd2+ for 3 weeks. The tightly packed structure composed by the axons, enlarged terminals, and glial cells, became loose and porous. Ultra-structurally, a large number of vacuoles and few neurosecretory granules were observed in the axon terminal. These effects added to our understanding of the toxic effects of Cd2+ and provide biochemical and histopathological evidence for S. henanense as a biomarker of acute or long-term waterborne Cd2+ pollution.
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Affiliation(s)
- Ruijing Xuan
- Laboratory Animal Center, Shanxi Medical University, Taiyuan, 030001, China
| | - Hao Wu
- Basic Medical School, Shanxi Medical University, Taiyuan, 030001, China
| | - Yingjun Li
- School of Public Health, Shanxi Medical University, Taiyuan, 030001, China
| | - Bingyan Wei
- Laboratory Animal Center, Shanxi Medical University, Taiyuan, 030001, China
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, China.
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Meng C, Wang K, Zhang X, Zhu X. Purification, secondary structure and antioxidant activity of metallothionein zinc-binding proteins from Arca subcrenata. Protein Expr Purif 2021; 182:105838. [PMID: 33561519 DOI: 10.1016/j.pep.2021.105838] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 12/13/2020] [Accepted: 01/28/2021] [Indexed: 11/29/2022]
Abstract
Zinc-binding proteins named MT-M-I and MT-M-II were obtained after purification from metal-exposed hairy clams (Arca subcrenata) using gel permeation and ion-exchange chromatography. MT-M-I and MT-M-II were resolved by ion-exchange chromatography, and they were found to have similar molecular weights. MT-M-I and MT-M-II can bind 6 and 7 equivalents of Zn2+ in vitro, and they showed unusual migration behaviors in Tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (Tricine-SDS-PAGE). Such migration behaviors may be due to themetal thiolate clusters in these proteins. In terms of amino acid composition, the proportion of cysteine in MT-M-I and MT-M-II was approximately 30%, and glycine accounted for approximately 15%, where as aromatic amino acids were absent. Considering the performance in Tricine-SDS-PAGE and the amino acid compositions, MT-M-I and MT-M-II conform to the molecular characteristics of the metallothionein proteins. The structures were explored using circular dichroism (CD) and Fourier-transform infrared spectroscopy (FTIR). Also determined the antioxidant activities in terms of DPPH radical scavenging ability, hydroxyl radical (·OH) scavenging ability, and ferric-reducing/antioxidant power. The antioxidant activities of MT-M-I were found to be stronger than those of MT-M-II.
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Affiliation(s)
- Chunying Meng
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China; Laboratory of Aquatic Product Processing and Quality Safety, Zhejiang Marine Fisheries Research Institute, Zhoushan, 316100, PR China
| | - Kuiwu Wang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China.
| | - Xiaojun Zhang
- Laboratory of Aquatic Product Processing and Quality Safety, Zhejiang Marine Fisheries Research Institute, Zhoushan, 316100, PR China
| | - Xinyue Zhu
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, PR China
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Ma W, Li X, Wang Q, Ren Z, Crabbe MJC, Wang L. Tandem oligomeric expression of metallothionein enhance heavy metal tolerance and bioaccumulation in Escherichia coli. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 181:301-307. [PMID: 31202929 DOI: 10.1016/j.ecoenv.2019.06.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/25/2019] [Accepted: 06/07/2019] [Indexed: 06/09/2023]
Abstract
Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich, metal-binding proteins, which play important roles in metal homeostasis and heavy metal detoxification. In our previous study, a novel full length MT cDNA was successfully cloned from the freshwater crab (Sinopotamon henanense). In the present study, tandem repeats of two and three copies of the crab MT gene were integrated by overlap extension PCR (SOE-PCR) and expressed in Escherichia coli. The SUMO fusion expression system was adopted to increase the stability and solubility of the recombinant MT proteins. The recombinant proteins were purified and their metal-binding abilities were further analyzed by the ultraviolet absorption spectral scan. Furthermore, the metal tolerance and bioaccumulation of E. coli cells expressing oligomeric MTs were determined. Results showed that the recombinant plasmids pET28a-SUMO-2MT and pET28a-SUMO-3MT were successfully constructed. SDS-PAGE analysis showed that the SUMO-2MT and SUMO-3MT were expressed mainly in the soluble forms. Oligomeric MTs expression significantly enhanced Cu, Cd or Zn tolerance and accumulation in E. coli in the order: SUMO-3MT˃SUMO-2MT˃SUMO-MT˃control. Cells harboring pET28a-SUMO -3MT exhibited the highest Cu, Cd or Zn bioaccumulation at 5.8-fold, 3.1-fold or 6.7-fold higher than that of the control cells. Our research could lay a foundation for large-scale preparation of MTs and provide a scientific basis for bioremediation of heavy metal pollution by oligomeric MTs.
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Affiliation(s)
- Wenli Ma
- School of Life Science, Shanxi University, Taiyuan, 030006, PR China.
| | - Xuefen Li
- School of Life Science, Shanxi University, Taiyuan, 030006, PR China
| | - Qi Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, PR China
| | - Zhumei Ren
- School of Life Science, Shanxi University, Taiyuan, 030006, PR China
| | - M James C Crabbe
- School of Life Science, Shanxi University, Taiyuan, 030006, PR China; Wolfson College, University of Oxford, Oxford, OX2 6UD, UK; Institute of Biomedical and Environmental Science & Technology, Faculty of Creative Arts, Technologies and Science, University of Bedfordshire, University Square, Luton, LU1 3JU, UK
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, PR China
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