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Mohammad F, Bwatanglang IB, Al-Lohedan HA, Shaik JP, Moosavi M, Dahan WM, Al-Tilasi HH, Aldhayan DM, Chavali M, Soleiman AA. Magnetically controlled drug delivery and hyperthermia effects of core-shell Cu@Mn 3O 4 nanoparticles towards cancer cells in vitro. Int J Biol Macromol 2023; 249:126071. [PMID: 37524291 DOI: 10.1016/j.ijbiomac.2023.126071] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/28/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023]
Abstract
Recent increase in the integration of nanotechnology and nanosciences to the biomedical sector fetches the human wellness through the development of sustainable treatment methodologies for cancerous tumors at all stages of their initiation and progression. This involves the development of multifunctional theranostic probes that effectively support for the early cancer diagnosis, avoiding non-target cell toxicity, controlled and customized anticancer drug release etc. Therefore, to advance the field of nanotechnology-based sustainable cancer treatment, we fabricated and tested the efficacy of anticancer drug-loaded magnetic hybrid nanoparticles (NPs) towards in vitro cell culture systems. The developed conjugate of NPs was incorporated with the functions of both controlled drug delivery and heat-releasing ability using Mn3O4 (manganese oxide) magnetic core with Cu shell encapsulated within trimethyl chitosan (TMC) biopolymer. On characterization, the Cu@Mn3O4-TMC NPs were confirmed to have an approximate size of 130 nm with full agglomeration (as observed by the HRTEM) and crystal size of 92.95 ± 18.38 nm with tetragonal hausmannite phase for Mn3O4 spinel structure (XRD). Also, the UV-Vis and FTIR analysis provided the qualitative and quantitative effects of 5-fluororacil (5-Fu) anticancer drug loading (max 68 %) onto the Cu@Mn3O4-TMC NPs. The DLS analysis indicated for the occurrence of no significant changes to the particle size (around 100 nm) of Cu@Mn3O4-TMC due to the solution dispersion thereby confirming for the aqueous stability of developed NPs. In addition, the magnetization values of Cu@Mn3O4-TMC NPs were measured to be 34 emu/g and a blocking temperature of 42 K. Further tests of magnetic hyperthermia by the Cu@Mn3O4-TMC/5-Fu NPs provided that the heat-releasing capacity (% ΔT at 15 min) increases with that of increased frequency, i.e. 28 % (440 Hz) > 22.6 % (240 Hz) > 18 % (44 Hz), and the highest specific power loss (SPL) value observed to be 488 W/g for water. Moreover, the 5-Fu drug release studies indicate that the release is high at a pH of 5.2 and almost all the loaded drug is getting delivered under the influence of the external magnetic field (430 Hz) due to the influence of both Brownian-rotation and Néel relaxation heat-mediated mechanism. The pharmacokinetic drug release studies have suggested for the occurrence of more than one model, i.e. First-order, Higuchi (diffusion), and Korsemeyer-Peppas (non-Fickian), in addition to hyperthermia. Finally, the in vitro cell culture systems (MCF-7 cancer and MCF-10 non-cancer) helped to differentiate the physiological changes due to the effects of hyperthermia and 5-Fu drug individually and as a combination of both. The observed differences of cell viability losses among both cell types are measured and discussed with the expression of heat shock proteins (HSPs) by the MCF-10 cells as against the MCF-7 cancer cells. We believe that the results generated in this project can be helpful for the designing of new cancer therapeutic models with nominal adverse effects on healthy normal cells and thus paving a way for the treatment of cancer and other deadly diseases in a sustainable manner.
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Affiliation(s)
- Faruq Mohammad
- Surfactants Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Ibrahim Birma Bwatanglang
- Department of Pure and Applied Chemistry, Faculty of Science, Adamawa State University, Mubi P.M.B. 25, Nigeria
| | - Hamad A Al-Lohedan
- Surfactants Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Jilani P Shaik
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Maryam Moosavi
- Nanotechnology Engineering, Faculty of Advance Technology and Multidiscipline, Universitas Airlangga, Jawa Timur 60115, Indonesia
| | - Wasmia Mohammed Dahan
- Surfactants Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Hissah Hamad Al-Tilasi
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Daifallah M Aldhayan
- Surfactants Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Murthy Chavali
- Office of the Dean (Research & Development), Dr. Vishwanath Karad MIT World Peace University (MIT-WPU), Kothrud, Pune, Maharashtra 411038, India
| | - Ahmed A Soleiman
- College of Sciences & Engineering, Southern University and A&M College, Baton Rouge, LA 70813, USA
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Zhao K, Wu H, Hou R, Wu J, Wang Y, Huang S, Cheng D, Xu H, Zhang Z. Effects of sublethal azadirachtin on the immune response and midgut microbiome of Apis cerana cerana (Hymenoptera: Apidae). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 229:113089. [PMID: 34929506 DOI: 10.1016/j.ecoenv.2021.113089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
As a wildly used plant-derived insecticide, azadirachtin (AZA) is commonly reported as harmless to a range of beneficial insects. However, with the research on the effect of AZA against pollinators in recent years, various negative physiological effects on other Apidae species have been demonstrated. Thus to explore the safety of azadirachtin to Apis cerana cerana, the different physiological effects of sublethal concentration of azadirachtin on worker bees A.c.cerana has been studied. With the exposure of 5 mg·L-1 and 10 mg·L-1 azadirachtin for 5 d, the relative expression of Apidaecin, Abaecin and Lysosome genes in workers has decreased significantly at 1, 2,3 and 5 d, and the mRNA levels of Defensin 2 and Hymenoptaecin were also significantly inhibited by 10 mg·L-1 azadirachtin at each check point. Besides, the activity of midgut antioxidant enzymes Superoxide Dismutase (SOD) and Catalase (CAT) which are the first line of defence in antioxidant systems was not affected by AZA, the activity of Peroxidase (POD) showed a fluctuating pattern at 24 h and 48 h, while the activity of polyphenol oxidase (PPO) has significantly inhibited by AZA. However, through 16sRNA analysis it was observed that 5 mg·L-1 AZA did not affect the midgut microbiome colony composition and relative abundance, as well as its main function. Therefore, to a certain extent, azadirachtin is safe for workers, but we should pay more attention to the sublethal effect of AZA that also detrimental to the healthy development of the honeybee colony.
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Affiliation(s)
- Kunyu Zhao
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Hao Wu
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Ruiquan Hou
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Jiyingzi Wu
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Yongqing Wang
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Suqing Huang
- Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Dongmei Cheng
- Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Hanhong Xu
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China.
| | - Zhixiang Zhang
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China.
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Shaik HA, Mishra A, Sehadová H, Kodrík D. Responses of sericotropin to toxic and pathogenic challenges: possible role in defense of the wax moth Galleria mellonella. Comp Biochem Physiol C Toxicol Pharmacol 2020; 227:108633. [PMID: 31644954 DOI: 10.1016/j.cbpc.2019.108633] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 11/29/2022]
Abstract
This study describes defense functions of the insect neuropeptide sericotropin, which is recognized as an agent that stimulates silk production in some lepidopteran larvae. Sericotropin, expressed in brain tissue of the wax moth Galleria mellonella in all developmental stages, is not expressed in silk glands, indicating its tissue specificity. Fluorescence microscopy confirmed the presence of sericotropin in the brain-subesophageal complex being predominantly and densely distributed under the plasmatic membrane and in axonal parts of neurons. Injection of venom from Habrobracon hebetor and topical application of the entomopathogenic nematode (EPN) Steinernema carpocapsae with symbiotic bacteria Xenorhabdus spp. into or onto G. mellonella larvae resulted in upregulation of the sericotropin gene and peptide, suggesting a role for sericotropin in defense and immunity. Accordingly, two synthetic fragments of sericotropin killed entomotoxic Xenorhabdus spp. bacteria in a disc diffusion antimicrobial test. Further, total metabolism, monitored by carbon dioxide production, significantly decreased after application of either venom or EPN, probably because of muscle impairment by the venom and serious cell damage caused by EPN, especially in the midgut. Both venom and EPN upregulated expression of genes encoding antimicrobial peptides gallerimycin and galiomicin in Galleria brain; however, they downregulated prophenoloxidase and phenoloxidase activity in hemolymph. These results suggest that sericotropin is a multifunctional peptide that plays an important role in G. mellonella defense and immunity.
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Affiliation(s)
- Haq Abdul Shaik
- Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Archana Mishra
- Institute of Molecular Biology of Plants, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Hana Sehadová
- Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Dalibor Kodrík
- Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
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Priyadarshi H, Das R, Kumar S, Kishore P, Kumar S. Analysis of variance, normal quantile-quantile correlation and effective expression support of pooled expression ratio of reference genes for defining expression stability. Heliyon 2017; 3:e00233. [PMID: 28127588 PMCID: PMC5247286 DOI: 10.1016/j.heliyon.2017.e00233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/16/2016] [Accepted: 01/09/2017] [Indexed: 11/19/2022] Open
Abstract
Identification of a reference gene unaffected by the experimental conditions is obligatory for accurate measurement of gene expression through relative quantification. Most existing methods directly analyze variability in crossing point (Cp) values of reference genes and fail to account for template-independent factors that affect Cp values in their estimates. We describe the use of three simple statistical methods namely analysis of variance (ANOVA), normal quantile-quantile correlation (NQQC) and effective expression support (EES), on pooled expression ratios of reference genes in a panel to overcome this issue. The pooling of expression ratios across the genes in the panel nullify the sample specific effects uniformly affecting all genes that are falsely reflected as instability. Our methods also offer the flexibility to include sample specific PCR efficiencies in estimations, when available, for improved accuracy. Additionally, we describe a correction factor from the ANOVA method to correct the relative fold change of a target gene if no truly stable reference gene could be found in the analyzed panel. The analysis is described on a synthetic data set to simplify the explanation of the statistical treatment of data.
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Affiliation(s)
- Himanshu Priyadarshi
- College of Fisheries (CAU-Imphal), Lembucherra, Tripura 799210, India
- Corresponding author at: Department of Fish Genetics and Reproduction, College of Fisheries (CAU-Imphal), Lembucherra, Tripura 799210, India.College of Fisheries (CAU-Imphal)LembucherraTripura799210India
| | - Rekha Das
- ICAR RC for NEH Region, Tripura 799210, India
| | - Shivendra Kumar
- Dr. Rajendra Prasad Central Agricultural University, Samastipur 848125, India
| | - Pankaj Kishore
- ICAR-Central Institute of Fisheries Technology, Cochin 682029, India
| | - Sujit Kumar
- ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
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Rattanarojpong T, Khankaew S, Khunrae P, Vanichviriyakit R, Poomputsa K. Recombinant baculovirus mediates dsRNA specific to rr2 delivery and its protective efficacy against WSSV infection. J Biotechnol 2016; 229:44-52. [PMID: 27164257 DOI: 10.1016/j.jbiotec.2016.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 04/27/2016] [Accepted: 05/03/2016] [Indexed: 01/11/2023]
Abstract
White spot syndrome virus (WSSV) is a major causative agent in shrimp farming. Consequently, RNAi technology is an effective strategy to prevent WSSV infection in shrimp especially dsRNA targeting to rr2 of WSSV. In an effort to develop dsRNA expression in shrimp for control of WSSV infection, we developed a recombinant baculovirus expressing recombinant VP28 as the gene delivery system to carry a gene encoding dsRNA specific to rr2 for triggering the RNAi process in shrimp. The results showed that the recombinant baculovirus harboring VP28 was able to express VP28 indicated by Western blot with polyclonal antibody specific to VP28. VP28 transcript was detected in shrimp hemocytes after co-culture hemocytes with the recombinant baculovirus displaying VP28. In addition, we found that shrimp injected with the recombinant baculovirus displaying VP28 and encoding dsRNA synthetic gene specific to rr2 (Bac-VP28-dsrr2) showed the lowest cumulative mortality (33%) at 14days post infection (dpi) when compared to shrimp injected with baculovirus displaying VP28 (Bac-VP28) (64% cumulative mortality) (p<0.05). According to the results, shrimp injected with Bac-VP28-dsrr2 also showed significantly lower WSSV copies than shrimp injected with Bac-VP28 (p<0.05) along with the down-regulation of rr2 expression at 1, 3 and 7dpi. In conclusion, the Bac-VP28-dsrr2 was effective in prevention of WSSV infection. Therefore, the results obtained here can be applied to the prevention of WSSV infection by mixing the recombinant baculovirus with shrimp feed in the future.
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Affiliation(s)
- Triwit Rattanarojpong
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
| | - Suthiwat Khankaew
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Pongsak Khunrae
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Rapeepun Vanichviriyakit
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Mahidol University, Bangkok 10400, Thailand
| | - Kanokwan Poomputsa
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
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Alvarez JV, Chung JS. The Involvement of Hemocyte Prophenoloxidase in the Shell-Hardening Process of the Blue Crab, Callinectes sapidus. PLoS One 2015; 10:e0136916. [PMID: 26393802 PMCID: PMC4634603 DOI: 10.1371/journal.pone.0136916] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/10/2015] [Indexed: 12/16/2022] Open
Abstract
Cuticular structures of arthropods undergo dramatic molt-related changes from being soft to becoming hard. The shell-hardening process of decapod crustaceans includes sclerotization and mineralization. Hemocyte PPO plays a central role in melanization and sclerotization particularly in wound healing in crustaceans. However, little is known about its role in the crustacean initial shell-hardening process. The earlier findings of the aggregation of heavily granulated hemocytes beneath the hypodermis during ecdysis imply that the hemocytes may be involved in the shell-hardening process. In order to determine if hemocytes and hemocyte PPO have a role in the shell-hardening of crustaceans, a knockdown study using specific CasPPO-hemo-dsRNA was carried out with juvenile blue crabs, Callinectes sapidus. Multiple injections of CasPPO-hemo-dsRNA reduce specifically the levels of CasPPO-hemo expression by 57% and PO activity by 54% in hemocyte lysate at the postmolt, while they have no effect on the total hemocyte numbers. Immunocytochemistry and flow cytometry analysis using a specific antiserum generated against CasPPO show granulocytes, semigranulocytes and hyaline cells as the cellular sources for PPO at the postmolt. Interestingly, the type of hemocytes, as the cellular sources of PPO, varies by molt stage. The granulocytes always contain PPO throughout the molt cycle. However, semigranulocytes and hyaline cells become CasPPO immune-positive only at early premolt and postmolt, indicating that PPO expression in these cells may be involved in the shell-hardening process of C. sapidus.
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Affiliation(s)
- Javier V. Alvarez
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Columbus Center, Baltimore, Maryland, United States of America
| | - J. Sook Chung
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Columbus Center, Baltimore, Maryland, United States of America
- * E-mail:
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Lu A, Zhang Q, Zhang J, Yang B, Wu K, Xie W, Luan YX, Ling E. Insect prophenoloxidase: the view beyond immunity. Front Physiol 2014; 5:252. [PMID: 25071597 PMCID: PMC4092376 DOI: 10.3389/fphys.2014.00252] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/17/2014] [Indexed: 11/13/2022] Open
Abstract
Insect prophenoloxidase (PPO) is an important innate immunity protein due to its involvement in cellular and humoral defense. It belongs to a group of type-3 copper-containing proteins that occurs in almost all organisms. Insect PPO has been studied for over a century, and the PPO activation cascade is becoming clearer. The insect PPO activation pathway incorporates several important proteins, including pattern-recognition receptors (PGRP, β GRP, and C-type lectins), serine proteases, and serine protease inhibitors (serpins). Due to their complexity, PPO activation mechanisms vary among insect species. Activated phenoloxidase (PO) oxidizes phenolic molecules to produce melanin around invading pathogens and wounds. The crystal structure of Manduca sexta PPO shows that a conserved amino acid, phenylalanine (F), can block the active site pocket. During activation, this blocker must be dislodged or even cleaved at the N-terminal sequence to expose the active site pockets and allow substrates to enter. Thanks to the crystal structure of M. sexta PPO, some domains and specific amino acids that affect PPO activities have been identified. Further studies of the relationship between PPO structure and enzyme activities will provide an opportunity to examine other type-3 copper proteins, and trace when and why their various physiological functions evolved. Recent researches show that insect PPO has a relationship with neuron activity, longevity, feces melanization (phytophagous insects) and development, which suggests that it is time for us to look back on insect PPO beyond the view of immunity in this review.
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Affiliation(s)
- Anrui Lu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Qiaoli Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Jie Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Bing Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Kai Wu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Wei Xie
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Yun-Xia Luan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Erjun Ling
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
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Lu A, Peng Q, Ling E. Formation of disulfide bonds in insect prophenoloxidase enhances immunity through improving enzyme activity and stability. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 44:351-358. [PMID: 24480295 DOI: 10.1016/j.dci.2014.01.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/13/2014] [Accepted: 01/14/2014] [Indexed: 06/03/2023]
Abstract
Type 3 copper proteins, including insect prophenoloxidase (PPO), contain two copper atoms in the active site pocket and can oxidize phenols. Insect PPO plays an important role in immunity. Insects and other invertebrates show limited recovery from pathogen invasion and wounds if phenoloxidase (PO) activity is low. In most insect PPOs, two disulfide bonds are present near the C-terminus. However, in Pimpla hypochondriaca (a parasitoid wasp), each PPO contains one disulfide bond. We thus questioned whether the formation of two sulfide bonds in insect PPOs improved protein stability and/or increased insect innate immunity over time. Using Drosophila melanogaster PPO1 as a model, one or two disulfide bonds were deleted to evaluate the importance of disulfide bonds in insect immunity. rPPO1 and mutants lacking disulfide bonds could be expressed and showed PO activity. However, the PO activities of mutants lacking one or two disulfide bonds significantly decreased. Deletion of disulfide bonds also reduced PPO thermostability. Furthermore, antibacterial activities against Escherichia coli and Bacillus subtilis significantly decreased when disulfide bonds were deleted. Therefore, the formation of two disulfide bond(s) in insect PPO enhances antibacterial activity by increasing PO activity and stability.
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Affiliation(s)
- Anrui Lu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China
| | - Qin Peng
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China
| | - Erjun Ling
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
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