1
|
Jaiswal S, Singh B, Dhingra I, Joshi A, Kodgire P. Bioremediation and bioscavenging for elimination of organophosphorus threats: An approach using enzymatic advancements. Environ Res 2024; 252:118888. [PMID: 38599448 DOI: 10.1016/j.envres.2024.118888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/06/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Organophosphorus compounds (OP) are highly toxic pesticides and nerve agents widely used in agriculture and chemical warfare. The extensive use of these chemicals has severe environmental implications, such as contamination of soil, water bodies, and food chains, thus endangering ecosystems and biodiversity. Plants absorb pesticide residues, which then enter the food chain and accumulate in the body fat of both humans and animals. Numerous human cases of OP poisoning have been linked to both acute and long-term exposure to these toxic OP compounds. These compounds inhibit the action of the acetylcholinesterase enzyme (AChE) by phosphorylation, which prevents the breakdown of acetylcholine (ACh) neurotransmitter into choline and acetate. Thus, it becomes vital to cleanse the environment from these chemicals utilizing various physical, chemical, and biological methods. Biological methods encompassing bioremediation using immobilized microbes and enzymes have emerged as environment-friendly and cost-effective approaches for pesticide removal. Cell/enzyme immobilized systems offer higher stability, reusability, and ease of product recovery, making them ideal tools for OP bioremediation. Interestingly, enzymatic bioscavengers (stoichiometric, pseudo-catalytic, and catalytic) play a vital role in detoxifying pesticides from the human body. Catalytic bioscavenging enzymes such as Organophosphate Hydrolase, Organophosphorus acid anhydrolase, and Paraoxonase 1 show high degradation efficiency within the animal body as well as in the environment. Moreover, these enzymes can also be employed to decontaminate pesticides from food, ensuring food safety and thus minimizing human exposure. This review aims to provide insights to potential collaborators in research organizations, government bodies, and industries to bring advancements in the field of bioremediation and bioscavenging technologies for the mitigation of OP-induced health hazards.
Collapse
Affiliation(s)
- Surbhi Jaiswal
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Brijeshwar Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Isha Dhingra
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Abhijeet Joshi
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
| |
Collapse
|
2
|
Vyas T, Jaiswal S, Choudhary S, Kodgire P, Joshi A. Recombinant Organophosphorus acid anhydrolase (OPAA) enzyme-carbon quantum dot (CQDs)-immobilized thin film biosensors for the specific detection of Ethyl Paraoxon and Methyl Parathion in water resources. Environ Res 2024; 243:117855. [PMID: 38070850 DOI: 10.1016/j.envres.2023.117855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/14/2023] [Accepted: 11/30/2023] [Indexed: 02/06/2024]
Abstract
Organophosphates pesticide (OP) toxicity through water resources is a large concern globally among all the emerging pollutants. Detection of OPs is a challenge which needs to be addressed considering the hazardous effects on the health of human beings. In the current research thin film biosensors of recombinant, Organophosphorus acid anhydrolase (OPAA) enzyme along with carbon quantum dots (CQDs) immobilized in thin films were developed. OPAA-CQDs thin film biosensors were used for the specific detection of two OPs Ethyl Paraoxon (EP) and Methyl Parathion (MP) in river water and household water supply. Recombinant OPAA enzyme was expressed in E. Coli, purified and immobilized on the CQD containing chitosan thin films. The CQDs used for this purpose were developed by a one-pot hydrothermal method from phthalic acid and Tri ethylene diamine. The properties of CQDs, OPAA and thin films were characterized using techniques like XPS, TEM, XRD, enzyme activity and CLSM measurements. Biosensing studies of EP and MP were performed by taking fluorescence measurements using a fiber optic spectrometer. The analytical parameters of biosensing were compared against an estimation carried out using the HPLC method. The biosensing performance indicates that the OPAA-CQDs thin film-based biosensors were able to detect both EP and MP in a range of 0-100 μM having a detection limit of 0.18 ppm/0.69 ppm for EP/MP, respectively with a response time of 5 min. The accuracy of estimation of EP/MP when spiked in water resources lie in the range of ∼100-102% which clearly indicates the OPAA-CQD based thin film biosensors can function as a point-of-use method for the detection of OP pesticides in complex water resources.
Collapse
Affiliation(s)
- Tanmay Vyas
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, 453552, Madhya Pradesh, India
| | - Surbhi Jaiswal
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, 453552, Madhya Pradesh, India
| | - Sandeep Choudhary
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, 453552, Madhya Pradesh, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, 453552, Madhya Pradesh, India.
| | - Abhijeet Joshi
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, 453552, Madhya Pradesh, India.
| |
Collapse
|
3
|
Jaiswal A, Roy R, Tamrakar A, Singh AK, Kar P, Kodgire P. Activation-induced cytidine deaminase an antibody diversification enzyme interacts with chromatin modifier UBN1 in B-cells. Sci Rep 2023; 13:19615. [PMID: 37949972 PMCID: PMC10638239 DOI: 10.1038/s41598-023-46448-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
Activation-induced cytidine deaminase (AID) is the key mediator of antibody diversification in activated B-cells by the process of somatic hypermutation (SHM) and class switch recombination (CSR). Targeting AID to the Ig genes requires transcription (initiation and elongation), enhancers, and its interaction with numerous factors. Furthermore, the HIRA chaperon complex, a regulator of chromatin architecture, is indispensable for SHM. The HIRA chaperon complex consists of UBN1, ASF1a, HIRA, and CABIN1 that deposit H3.3 onto the DNA, the SHM hallmark. We explored whether UBN1 interacts with AID using computational and in-vitro experiments. Interestingly, our in-silico studies, such as molecular docking and molecular dynamics simulation results, predict that AID interacts with UBN1. Subsequently, co-immunoprecipitation and pull-down experiments established interactions between UBN1 and AID inside B-cells. Additionally, a double immunofluorescence assay confirmed that AID and UBN1 were co-localized in the human and chicken B-cell lines. Moreover, proximity ligation assay studies validated that AID interacts with UBN1. Ours is the first report on the interaction of genome mutator enzyme AID with UBN1. Nevertheless, the fate of interaction between UBN1 and AID is yet to be explored in the context of SHM or CSR.
Collapse
Affiliation(s)
- Ankit Jaiswal
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, 453 552, India
| | - Rajarshi Roy
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, 453 552, India
| | - Anubhav Tamrakar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, 453 552, India
| | - Amit Kumar Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, 453 552, India
| | - Parimal Kar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, 453 552, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, 453 552, India.
| |
Collapse
|
4
|
Singh B, Jaiswal S, Kodgire P. Outer membrane proteins and vesicles as promising vaccine candidates against Vibrio spp. infections. Crit Rev Microbiol 2023:1-17. [PMID: 37272649 DOI: 10.1080/1040841x.2023.2212072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Indiscriminate use of antibiotics to treat bacterial infections has brought unmanageable antibiotic-resistant strains into existence. Vibrio spp. represents one such gram-negative enteric pathogenic group with more than 100 species, infecting humans and fish. The Vibrio spp. is demarcated into two groups, one that causes cholera and the other producing non-cholera or vibriosis infections. People who encounter contaminated water are at risk, but young children and pregnant women are the most vulnerable. Though controllable, Vibrio infection still necessitates the development of preventative measures, such as vaccinations, that can lessen the severity of the infection and reduce reliance on antibiotic use. With emerging multi-drug resistant strains, efforts are needed to develop newer vaccines, such as subunit-based or outer membrane vesicle-based. Thus, this review strives to bring together available information about Vibrio spp. outer membrane proteins and vesicles, encompassing their structure, function, and immunoprotective role.
Collapse
Affiliation(s)
- Brijeshwar Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Surbhi Jaiswal
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| |
Collapse
|
5
|
Chaudhari R, Singh K, Kodgire P. Biochemical and molecular mechanisms of antibiotic resistance in Salmonella spp. Res Microbiol 2023; 174:103985. [PMID: 35944794 DOI: 10.1016/j.resmic.2022.103985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 01/11/2023]
Abstract
Salmonella is a diverse Gram-negative bacterium that represents the major disease burden worldwide. According to WHO, Salmonella is one of the fourth global causes of diarrhoeal disease. Antibiotic resistance is a worldwide health concern, and Salmonella spp. is one of the microorganisms that can evade the toxicity of antimicrobials via antibiotic resistance. This review aims to deliver in-depth knowledge of the molecular mechanisms and the underlying biochemical alterations perceived in antibiotic resistance in Salmonella. This information will help understand and mitigate the impact of antibiotic-resistant bacteria on humans and contribute to the state-of-the-art research developing newer and more potent antibiotics.
Collapse
Affiliation(s)
- Rahul Chaudhari
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore 453552, India
| | - Kanika Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore 453552, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore 453552, India.
| |
Collapse
|
6
|
Abstract
Diagnosis of prostate cancer (PC) has posed a challenge worldwide due to the sophisticated and costly diagnostics tools, which include DRE, TRUS, GSU, PET/CT scan, MRI, and biopsy. These diagnostic techniques are very helpful in the detection of PCs; however, all the techniques have their serious limitations. Biosensors are easier to fabricate and do not require any cutting-edge technology as required for other imaging techniques. In this regard, point-of-care (POC) biosensors are important due to their portability, convenience, low cost, and fast procedure. This review explains the various existing diagnostic tools for the detection of PCs and the limitation of these methods. It also focuses on the recent studies on biosensors technologies as an alternative to the conventional diagnostic techniques for the detection of PCs.
Collapse
Affiliation(s)
- Sourav Sarkar
- Department of Biomedical Engineering, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Manashjit Gogoi
- Department of Biomedical Engineering, North-Eastern Hill University, Shillong, 793022, Meghalaya, India.
| | - Mrityunjoy Mahato
- Physics Division, Department of Basic Sciences and Social Sciences, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Abhijeet Balwantrao Joshi
- Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore-453552, Madhya Pradesh, India
| | - Arup Jyoti Baruah
- Department of General Surgery, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, Meghalaya, India
| | - Prashant Kodgire
- Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore-453552, Madhya Pradesh, India
| | - Polina Boruah
- Department of Biochemistry, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong-793018, Meghalaya, India
| |
Collapse
|
7
|
Vyas T, Singh V, Kodgire P, Joshi A. Insights in detection and analysis of organophosphates using organophosphorus acid anhydrolases (OPAA) enzyme-based biosensors. Crit Rev Biotechnol 2022; 43:521-539. [PMID: 35504858 DOI: 10.1080/07388551.2022.2052012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The human population is dependent on agriculture for its food requirements and survival. Several insecticides and pesticides have found their use for improvements in agricultural yields. Organophosphates (OP) are one of the many compounds used as insecticides and pesticides. OPs have also been used to develop G and V-series chemicals which act as highly toxic nerve agents that can severely influence the normal function of the nervous system in all living beings. Thus, OP compounds utilized as insecticides/pesticides and nerve agents are hazardous to the environment, lethal for humans and other non-target animals. To avoid their toxicity, approaches to detect and neutralize them have become essential. A variety of analytical procedures such as electrochemical processes and chromatography methods, namely liquid and gas chromatography, have been employed to detect OPs. Though these techniques are sensitive and highly accurate they suffer from drawbacks, for instance: their bulky nature and expensive instrumentation, the difficulty of operation, long detection times, and they can yield unpredictable results with variable sample complexities. With the advent of several types of biosensors, the assay of OP compounds has become simpler, faster, cost-effective with improved sensitivity, and provides the capability for onsite detection. OP biosensor assays typically utilize several enzymes with the capability to hydrolyze/degrade OP compounds, such as organophosphate hydrolase (OPH) and organophosphate acid hydrolase (OPAA). This review focuses on discussing various aspects of OPAA as biological recognition unit in terms of its: structure, properties, activity enhancement methods, and utilization for developing OPAA-based biosensing technologies for insecticides, pesticides, and nerve agents.
Collapse
Affiliation(s)
- Tanmay Vyas
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Vinay Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Abhijeet Joshi
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| |
Collapse
|
8
|
Tamrakar A, Singh R, Kumar A, Makde RD, Ashish, Kodgire P. Biophysical characterization of the homodimers of HomA and HomB, outer membrane proteins of Helicobacter pylori. Sci Rep 2021; 11:24471. [PMID: 34963695 PMCID: PMC8714817 DOI: 10.1038/s41598-021-04039-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 11/24/2021] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori is a Gram-negative bacterium that causes chronic inflammations in the stomach area and is involved in ulcers, which can develop into gastric malignancies. H. pylori attaches and colonizes to the human epithelium using some of their outer membrane proteins (OMPs). HomB and HomA are the most studied OMPs from H. pylori as they play a crucial role in adherence, hyper biofilm formation, antibiotic resistance and are also associated with severe gastric malignancies. The role of HomA and HomB in pathogenesis concerning their structure and function has not been evaluated yet. In the present study, we explored the structural aspect of HomA and HomB proteins using various computational, biophysical and small-angle X-ray scattering (SAXS) techniques. Interestingly, the in-silico analysis revealed that HomA/B consists of 8 discontinuous N and C terminal β-strands forming a small β-barrel, along with a large surface-exposed globular domain. Further, biophysical experiments suggested that HomA and HomB are dimeric and most likely the cysteine residues present on surface-exposed loops participate in protein-protein interactions. Our study provides essential structural information of unexplored proteins of the Hom family that can help in a better understanding of H. pylori pathogenesis.
Collapse
Affiliation(s)
- Anubhav Tamrakar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453 552, India
| | - Rahul Singh
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai, India
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453 552, India
| | - Ravindra D Makde
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai, India
| | - Ashish
- Protein Science and Engineering Division, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453 552, India.
| |
Collapse
|
9
|
Jain M, Yadav P, Joshi B, Joshi A, Kodgire P. Recombinant organophosphorus hydrolase (OPH) expression in E. coli for the effective detection of organophosphate pesticides. Protein Expr Purif 2021; 186:105929. [PMID: 34139322 DOI: 10.1016/j.pep.2021.105929] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 05/18/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022]
Abstract
Accumulation and exposure of organophosphate pesticides are of great concern today owing to their abundant usage and potential health hazards. Harmful effects of organophosphate pesticide exposure and limitations of the available treatment methods necessitate the development of reliable, selective, cost-effective, and sensitive methods of detection. We developed a novel biosensor based on the enzymatic action of recombinant organophosphorus hydrolase (OPH) expressed in E. coli. We report the development of colorimetric biosensors made of His-Nus-OPH as well as His-Nus-OPH loaded alginate microspheres. The colorimetric detection method developed using solution-phase and alginate-encapsulated His-Nus-OPH exhibited detection limits of 0.045 and 0.039 mM, respectively, for ethyl paraoxon, and 0.101 and 0.049 mM, respectively, for methyl parathion. Additionally, fluorescence measurement using pH-sensitive fluorescein isothiocyanate (FITC) was used to sense the quantity of organophosphorus pesticides. The fluorometric detection method using solution-phase His-Nus-OPH, with ethyl paraoxon and methyl parathion as the substrate, reveals the lower limit of detection as 0.014 mM and 0.044 mM, respectively. Our results demonstrate the viability of His-Nus-OPH for OP detection with good sensitivity, LOD, and linear range. We report the first use of N-terminal His-NusA-tagged OPH, which enhances solubility significantly and presents a significant advance for the scientific community.
Collapse
Affiliation(s)
- Monika Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Priyanka Yadav
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Bhavana Joshi
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Abhijeet Joshi
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
| |
Collapse
|
10
|
Jain M, Yadav P, Joshi B, Joshi A, Kodgire P. A novel biosensor for the detection of organophosphorus (OP)-based pesticides using organophosphorus acid anhydrolase (OPAA)-FL variant. Appl Microbiol Biotechnol 2020; 105:389-400. [PMID: 33191461 DOI: 10.1007/s00253-020-11008-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 10/28/2020] [Accepted: 11/08/2020] [Indexed: 11/25/2022]
Abstract
Indiscriminate use of organophosphorus (OP)-based insecticides is a great concern to human health because of bioaccumulation-induced health hazards. Potentially fatal consequences and limited treatment methods of OP poisoning necessitate the need for the development of reliable, selective, cost-effective, and sensitive methods of OP detection. To tackle this issue, the development of effective devices and methods is required to sensitively detect as well as degrade OPs. Enzymatic sensor systems have gained popularity due to high catalytic activity, enhanced detection limits, and high sensitivity with the environmentally benign operation. Organophosphorus acid anhydrolase (OPAA) from Alteromonas sp. JD6.5 is capable of hydrolyzing the P-F, P-O, P-S, and P-CN bonds, in OPs, including nerve agents of the G/V-series. Several mutants of OPAA are reported which have greater activity against various OPs. In this study, recombinant expression of the OPAA-FL variant in Escherichia coli was performed, purified, and subsequently tested for activity against ethyl paraoxon. OPAA-FL variant showed its optimum activity at pH 8.5 and 50 °C. Colorimetric and fluorometric assays were used for estimation of ethyl paraoxon based on p-nitrophenol and fluorescein isothiocyanate (FITC) fluorescence intensity, respectively. Colorimetric and fluorometric assay estimation indicates that ethyl paraoxon can be estimated in the linear range of 0.01 to 1 mM and 0.1 to 0.5 mM, with LOD values 0.04 mM and 0.056 mM, respectively. Furthermore, the OPAA-FL variant was immobilized into alginate microspheres for colorimetric detection of ethyl paraoxon and displayed a linear range of 0.025 to 1 mM with a LOD value of 0.06 mM. KEY POINTS: • Biosensing of paraoxon with purified and encapsulated OPAA-FL variant. • Colorimetric and fluorometric biosensing assay developed using OPAA-FL variant for paraoxon. • First report on alginate encapsulation of OPAA-FL variant for biosensing of paraoxon. Graphical abstract.
Collapse
Affiliation(s)
- Monika Jain
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, India
| | - Priyanka Yadav
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, India
| | - Bhavana Joshi
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, India
| | - Abhijeet Joshi
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, India.
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore, India.
| |
Collapse
|
11
|
Shankar U, Jain N, Majee P, Kodgire P, Sharma TK, Kumar A. Exploring Computational and Biophysical Tools to Study the Presence of G-Quadruplex Structures: A Promising Therapeutic Solution for Drug-Resistant Vibrio cholerae. Front Genet 2020; 11:935. [PMID: 33101360 PMCID: PMC7545536 DOI: 10.3389/fgene.2020.00935] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/27/2020] [Indexed: 12/21/2022] Open
Abstract
Vibrio cholerae, a gram-negative bacterium that causes cholera, has already caused seven major pandemics across the world and infects roughly 1.3–4 million people every year. Cholera treatment primarily involves oral rehydration therapy supplemented with antibiotics. But recently, multidrug-resistant strains of V. cholerae have emerged. High genomic plasticity further enhances the pathogenesis of this human pathogen. Guanines in DNA or RNA assemble to form G-quadruplex (GQ) structures which have begun to be seen as potential drug targeting sites for different pathogenic bacteria and viruses. In this perspective, we carried out a genome-wide hunt in V. cholerae using a bio-informatics approach and observed ∼85 G-quadruplex forming motifs (VC-PGQs) in chromosome I and ∼45 putative G-quadruplexs (PGQs) in chromosome II. Ten putative G-quadruplex forming motifs (VC-PGQs) were selected on the basis of conservation throughout the genus and functional analysis displayed their location in the essential genes encoding bacterial proteins, for example, methyl-accepting chemotaxis protein, orotate phosphoribosyl transferase protein, amidase proteins, etc. The predicted VC-PGQs were validated using different bio-physical techniques, including Nuclear Magnetic Resonance spectroscopy, Circular Dichroism spectroscopy, and electrophoretic mobility shift assay, which demonstrated the formation of highly stable GQ structures in the bacteria. The interaction of these VC-PGQs with the known specific GQ ligand, TMPyP4, was analyzed using ITC and molecular dynamics studies that displayed the stabilization of the VC-PGQs by the GQ ligands and thus represents a potential therapeutic strategy against this enteric pathogen by inhibiting the PGQ harboring gene expression, thereby inhibiting the bacterial growth and virulence. In summary, this study reveals the presence of conserved GQ forming motifs in the V. cholerae genome that has the potential to be used to treat the multi-drug resistance problem of the notorious enteric pathogen.
Collapse
Affiliation(s)
- Uma Shankar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Neha Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Prativa Majee
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | | | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| |
Collapse
|
12
|
Jaiswal A, Singh AK, Tamrakar A, Kodgire P. Unfolding the Role of Splicing Factors and RNA Debranching in AID Mediated Antibody Diversification. Int Rev Immunol 2020; 40:289-306. [PMID: 32924658 DOI: 10.1080/08830185.2020.1815725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Activated B-cells diversify their antibody repertoire via somatic hypermutation (SHM) and class switch recombination (CSR). SHM is restricted to the variable region, whereas, CSR is confined to the constant region of immunoglobulin (Ig) genes. Activation-induced cytidine deaminase (AID) is a crucial player in the diversification of antibodies in the activated B-cell. AID catalyzes the deamination of cytidine (C) into uracil (U) at Ig genes. Subsequently, low fidelity repair of U:G mismatches may lead to mutations. Transcription is essential for the AID action, as it provides a transient single-strand DNA substrate. Since splicing is a co-transcriptional event, various splicing factors or regulators influence the transcription. Numerous splicing factors are known to regulate the AID targeting, function, Ig transcription, and AID splicing, which eventually influence antibody diversification processes. Splicing regulator SRSF1-3, a splicing isoform of serine arginine-rich splicing factor (SRSF1), and CTNNBL1, a spliceosome interacting factor, interact with AID and play a critical role in SHM. Likewise, a splicing regulator polypyrimidine tract binding protein-2 (PTBP2) and the debranching enzyme (DBR1) debranches primary switch transcripts which later forms G-quadruplex structures, and the S region guide RNAs direct AID to S region DNA. Moreover, AID shows several alternate splicing isoforms, like AID devoid of exon-4 (AIDΔE4) that is expressed in various pathological conditions. Interestingly, RBM5, a splicing regulator, is responsible for the skipping of AID exon 4. In this review, we discuss the role and significance of splicing factors in the AID mediated antibody diversification.
Collapse
Affiliation(s)
- Ankit Jaiswal
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
| | - Amit Kumar Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
| | - Anubhav Tamrakar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
| |
Collapse
|
13
|
Jain N, Mishra SK, Shankar U, Jaiswal A, Sharma TK, Kodgire P, Kumar A. G-quadruplex stabilization in the ions and maltose transporters gene inhibit Salmonella enterica growth and virulence. Genomics 2020; 112:4863-4874. [PMID: 32898642 PMCID: PMC7474834 DOI: 10.1016/j.ygeno.2020.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 07/15/2020] [Accepted: 09/03/2020] [Indexed: 12/20/2022]
Abstract
The G-quadruplex structure is a highly conserved drug target for preventing infection of several human pathogens. We tried to explore G-quadruplex forming motifs as promising drug targets in the genome of Salmonella enterica that causes enteric fever in humans. Herein, we report three highly conserved G-quadruplex motifs (SE-PGQ-1, 2, and 3) in the genome of Salmonella enterica. Bioinformatics analysis inferred the presence of SE-PGQ-1 in the regulatory region of mgtA, SE-PGQ-2 in ORF of entA, and SE-PGQ-3 in the promoter region of malE and malK genes. The G-quadruplex forming sequences were confirmed by biophysical and biomolecular techniques. Cellular studies affirm the inhibitory effect of G-quadruplex specific ligands on Salmonella enterica growth. Further, PCR inhibition, reporter based assay, and RT-qPCR assays emphasize the biological relevance of G-quadruplexes in these genes. Thus, this study confirmed the presence of G-quadruplex motifs in Salmonella enterica and characterized them as a promising drug target.
Collapse
Affiliation(s)
- Neha Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Simrol, Indore 453552, India
| | - Subodh Kumar Mishra
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Simrol, Indore 453552, India
| | - Uma Shankar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Simrol, Indore 453552, India
| | - Ankit Jaiswal
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Simrol, Indore 453552, India
| | - Tarun Kumar Sharma
- Translational Health Science and Technology Institute, Faridabad, Haryana 121001, India
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Simrol, Indore 453552, India
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Simrol, Indore 453552, India.
| |
Collapse
|
14
|
Singh AK, Tamrakar A, Jaiswal A, Kanayama N, Kodgire P. SRSF1-3, a splicing and somatic hypermutation regulator, controls transcription of IgV genes via chromatin regulators SATB2, UBN1 and histone variant H3.3. Mol Immunol 2020; 119:69-82. [DOI: 10.1016/j.molimm.2020.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/01/2020] [Accepted: 01/11/2020] [Indexed: 12/21/2022]
|
15
|
Singh AK, Jaiswal A, Kodgire P. AID preferentially targets the top strand in nucleosome sequences. Mol Immunol 2019; 112:198-205. [DOI: 10.1016/j.molimm.2019.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 04/29/2019] [Accepted: 05/31/2019] [Indexed: 02/06/2023]
|
16
|
Jain M, Yadav P, Joshi A, Kodgire P. Advances in detection of hazardous organophosphorus compounds using organophosphorus hydrolase based biosensors. Crit Rev Toxicol 2019; 49:387-410. [DOI: 10.1080/10408444.2019.1626800] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Monika Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Priyanka Yadav
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Abhijeet Joshi
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, India
| |
Collapse
|
17
|
Bhattacharya A, Bhowmik S, Singh AK, Kodgire P, Das AK, Mukherjee TK. Direct Evidence of Intrinsic Blue Fluorescence from Oligomeric Interfaces of Human Serum Albumin. Langmuir 2017; 33:10606-10615. [PMID: 28930631 DOI: 10.1021/acs.langmuir.7b02463] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The molecular origin behind the concentration-dependent intrinsic blue fluorescence of human serum albumin (HSA) is not known yet. This unusual blue fluorescence is believed to be a characteristic feature of amyloid-like fibrils of protein/peptide and originates due to the delocalization of peptide bond electrons through the extended hydrogen bond networks of cross-β-sheet structure. Herein, by combining the results of spectroscopy, size exclusion chromatography, native gel electrophoresis, and confocal microscopy, we have shown that the intrinsic blue fluorescence of HSA exclusively originates from oligomeric interfaces devoid of any amyloid-like fibrillar structure. Our study suggests that this low energy fluorescence band is not due to any particular residue/sequence, but rather it is a common feature of self-assembled peptide bonds. The present findings of intrinsic blue fluorescence from oligomeric interfaces pave the way for future applications of this unique visual phenomenon for early stage detection of various protein aggregation related human diseases.
Collapse
Affiliation(s)
- Arpan Bhattacharya
- Discipline of Chemistry, Indian Institute of Technology Indore , Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Soumitra Bhowmik
- Discipline of Chemistry, Indian Institute of Technology Indore , Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Amit K Singh
- Centre of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore , Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Prashant Kodgire
- Centre of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore , Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Apurba K Das
- Discipline of Chemistry, Indian Institute of Technology Indore , Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Tushar Kanti Mukherjee
- Discipline of Chemistry, Indian Institute of Technology Indore , Khandwa Road, Indore 453552, Madhya Pradesh, India
| |
Collapse
|
18
|
Abstract
Activation-induced cytidine deaminase (AID), primarily expressed in activated mature B lymphocytes in germinal centers, is the key factor in adaptive immune response against foreign antigens. AID is responsible for producing high-affinity and high-specificity antibodies against an infectious agent, through the physiological DNA alteration processes of antibody genes by somatic hypermutation (SHM) and class-switch recombination (CSR) and functions by deaminating deoxycytidines (dC) to deoxyuridines (dU), thereby introducing point mutations and double-stranded chromosomal breaks (DSBs). The beneficial physiological role of AID in antibody diversification is outweighed by its detrimental role in the genesis of several chronic immune diseases, under non-physiological conditions. This review offers a comprehensive and better understanding of AID biology and its pathological aspects, as well as addresses the challenges involved in AID-related cancer therapeutics, based on various recent advances and evidence available in the literature till date. In this article, we discuss ways through which our interpretation of AID biology may reflect upon novel clinical insights, which could be successfully translated into designing clinical trials and improving patient prognosis and disease management.
Collapse
Affiliation(s)
- Meenal Choudhary
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Anubhav Tamrakar
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Amit Kumar Singh
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Monika Jain
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Ankit Jaiswal
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Prashant Kodgire
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| |
Collapse
|
19
|
Kodgire P, Mukkawar P, Ratnam S, Martin TE, Storb U. Changes in RNA polymerase II progression influence somatic hypermutation of Ig-related genes by AID. ACTA ACUST UNITED AC 2013; 210:1481-92. [PMID: 23752228 PMCID: PMC3698518 DOI: 10.1084/jem.20121523] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ongoing transcription of the Ig gene coupled with temporary pausing within the targeted region facilitates somatic hypermutation. Somatic hypermutation (SHM) of Ig genes is initiated by the activation-induced cytidine deaminase (AID), and requires target gene transcription. We previously proposed that AID may associate with the RNA polymerase II (Pol). Here, to determine aspects of the transcription process required for SHM, we knocked-in a transcription terminator into an Ig gene variable region in DT40 chicken B cell line. We found that the human β-globin terminator was an efficient inhibitor of downstream transcription in these cells. The terminator reduced mutations downstream of the poly(A) signal, suggesting that the process of transcription is essential for efficient SHM and that AID has better access to its target when Pol is in the elongating rather than terminating mode. Mutations upstream of the poly(A) site were almost doubled in the active terminator clones compared with an inactivated terminator, and this region showed more single-stranded DNA, indicating that Pol pausing assists SHM. Moreover, the nontranscribed DNA strand was the preferred SHM target upstream of the active terminator. Pol pausing during poly(A) site recognition may facilitate persistence of negative supercoils, exposing the coding single strand and possibly allowing the nascent RNA intermittent reannealing with the template strand, for prolonged access of AID.
Collapse
Affiliation(s)
- Prashant Kodgire
- Department of Molecular Genetics and Cell Biology, University of Chicago, IL 60637, USA
| | | | | | | | | |
Collapse
|
20
|
Abstract
The process of somatic hypermutation (SHM) of immunoglobulin (Ig) genes requires activation-induced cytidine deaminase (AID). Although mistargeting of AID is detrimental to genome integrity, the mechanism and the cis-elements responsible for targeting of AID are largely unknown. We show that three CAGGTG cis-elements in the context of Ig enhancers are sufficient to target SHM to a nearby transcribed gene. The CAGGTG motif binds E47 in nuclear extracts of the mutating cells. Replacing CAGGTG with AAGGTG in the construct without any other E47 binding site eliminates SHM. The CA versus AA effect requires AID. CAGGTG does not enhance transcription, chromatin acetylation, or overall target gene activity. The other cis-elements of Ig enhancers alone cannot attract the SHM machinery. Collectively with other recent findings, we postulate that AID targets all genes expressed in mutating B cells that are associated with CAGGTG motifs in the appropriate context. Ig genes are the most highly mutated genes, presumably because of multiple CAGGTG motifs within the Ig genes, high transcription activity, and the presence of other cooperating elements in Ig enhancers.
Collapse
Affiliation(s)
- Atsushi Tanaka
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA
| | | | | | | | | |
Collapse
|
21
|
Abstract
In Bacillus subtilis, the transition state regulator ScoC indirectly, negatively regulates the anti-sigmaD factor FlgM in a SinR-dependent pathway leading to an increased availability of sigmaD. In addition to the SinR-dependent pathway, ScoC negatively regulates FlgM via directly repressing flgM transcription by binding to two sites in the promoter region of the flgM operon. Our studies also show that the regulation of FlgM by SinR is not at the transcriptional or translational levels. Thus, ScoC shows a dual mode of downregulation of FlgM, via both SinR-dependent and -independent pathways, which eventually results in the increased sigmaD activity.
Collapse
|
22
|
Kodgire P, Rao KK. hag expression in Bacillus subtilis is both negatively and positively regulated by ScoC. Microbiology (Reading) 2009; 155:142-149. [PMID: 19118355 DOI: 10.1099/mic.0.021899-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Bacillus subtilis, motility and chemotaxis require the expression of hag, which encodes flagellin. This gene is transcribed by the sigma(D) form of RNA polymerase and is regulated by a group of proteins called transition state regulators (TSRs). Our studies show that hag transcription is negatively regulated by the transition state regulator ScoC, by binding to its promoter. Furthermore, ScoC, indirectly, also positively regulates hag by increasing the availability of sigma(D) by downregulating the levels of the anti-sigma(D)-factor FlgM. We further show that the positive regulation by ScoC predominates over the negative regulation.
Collapse
Affiliation(s)
- Prashant Kodgire
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - K Krishnamurthy Rao
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| |
Collapse
|
23
|
Abstract
Negative regulation of epr in Bacillus subtilis 168 is mediated jointly by both ScoC and SinR, which bind to their respective target sites 62 bp apart. Increasing the distance between the two sites abolishes repression, indicating that the two proteins interact, thereby suggesting a mechanism of corepression.
Collapse
Affiliation(s)
- Prashant Kodgire
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | | |
Collapse
|
24
|
Murudkar CS, Kodgire P, Krishnamurthy Rao K. The carboxy terminal domain of Epr, a minor extracellular serine protease, is essential for the swarming motility ofBacillus subtilis168. FEMS Microbiol Lett 2006; 257:24-31. [PMID: 16553828 DOI: 10.1111/j.1574-6968.2006.00151.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
In this study we have investigated the role of Epr, a minor extracellular serine protease, in the swarming motility of Bacillus subtilis 168. We identified that the protease activity of Epr was dispensable for swarming. Since the protease activity of Epr was confined to its N-terminal domain, we hypothesized instead that its C-terminal domain (CTD) could be critical for swarming. Our study showed that not only the expression of Epr-CTD was necessary, but also its secretion was crucial for the swarming motility of B. subtilis 168.
Collapse
Affiliation(s)
- Charuta S Murudkar
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India.
| | | | | |
Collapse
|
25
|
Kar S, Pradhan B, Sinha RK, Kundu T, Kodgire P, Rao KK, Puranik VG, Lahiri GK. Synthesis, structure, redox, NLO and DNA interaction aspects of [{(L′–‴)2RuII}3(μ3-L)]3+and [(L′)2RuII(NC5H4S−)]+[L3−= 1,3,5-triazine-2,4,6-trithiolato, L′–‴ = arylazopyridine]. Dalton Trans 2004:1752-60. [PMID: 15252573 DOI: 10.1039/b403332a] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The trinuclear complexes [(L'-'")2RuII)3(mu3-L)](ClO4)3, [1] (ClO4)3-[3](ClO4)3 (L = trianionic form of 1,3,5-triazine-2,4,6-trithiol; N(p)C(5)H(4)N=N(a)-C6H4(R), R = H (L'), m-Me (L"), p-Me (L'")) and the analogous mononuclear complex [(L')2RuII(NC5H4S-)]ClO4 [4] ClO4 were synthesized. Crystal structures of [1](ClO4)3 and [4]ClO4 were determined. [1](3+)-[3](3+) exhibit three successive oxidative couples corresponding to Ru(II)Ru(II)Ru(III)<==>Ru(II)Ru(II)Ru(II); Ru(II)Ru(III)Ru(III)<==>Ru(II)Ru(II)Ru(III); Ru(III)Ru(III)Ru(III)<==>Ru(II)Ru(III)Ru(III) where the mixed valent states are moderately coupled. The complexes display multiple reductions associated with the azo functions of the ancillary ligands (L'-'"). The energy of the Ru(II)-based lowest energy MLCT transitions (533-558 nm) involving the pi* level of azoimine chromophore of L'-'" varies depending on the nuclearity as well as substituents in the ligand framework and follows the order: [1](3+) > [2](3+) > [3](3+) > [4](+). The complexes exhibit reasonably high third-order non-linear optical properties with gamma= (0.90-2.45) [times] 10(-29) esu. The interactions of the trinuclear complexes [((L')2RuII)3(mu3-L)]3+[1]3+, [((bpy)2RuII)3((mu3-L)]3+[5]3+ and [((phen)2RuII)3((mu3)-L)]3+[6]3+(bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline) with the circular and linear forms of p-Bluescript DNA show reduced ethidium bromide fluorescence on gel electrophoresis.
Collapse
Affiliation(s)
- Sanjib Kar
- Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India
| | | | | | | | | | | | | | | |
Collapse
|