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Jeyarajan S, Peter AS, Sathyan A, Ranjith S, Kandasamy I, Duraisamy S, Chidambaram P, Kumarasamy A. Expression and purification of epinecidin-1 variant (Ac-Var-1) by acid cleavage. Appl Microbiol Biotechnol 2024; 108:176. [PMID: 38277014 PMCID: PMC10817847 DOI: 10.1007/s00253-024-13017-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 12/19/2023] [Accepted: 01/11/2024] [Indexed: 01/27/2024]
Abstract
The demand for massive quantities of therapeutic active antimicrobial peptides (AMPs) is high due to their potential as alternatives to antibiotics. However, each antimicrobial peptide has unique properties, necessitating distinct synthesis and purification strategies for their large-scale production. In this study, we bio-synthesized and purified a functional enhanced variant of the AMP epinecidin-1, known as Ac-Var-1 (acid-cleavable variant-1). To generate the active peptide, we cloned the gene for Ac-Var-1 with acid-cleavable site (aspartic acid-proline) into the pET-32a expression vector, purified the fusion protein by His tag enrichment chromatography, and performed acid cleavage to release the active Ac-Var-1 peptide. After acid cleavage, the active Ac-Var-1 was purified and characterized by SDS-PAGE and mass spectrometry. The results from both techniques provided confirmation of the intactness of the purified Ac-Var-1. The Ac-Var-1 inhibited the growth of pathogenic Escherichia coli and Staphylococcus aureus. KEY POINTS : • Epinecidin-1 is a well-known antimicrobial peptide having multipotential bioactivities. • Epinecidin-1 variant is developed via the site-directed mutagenesis method to improve its structural stability and bioactivity. • AC-Var-1 development is an economical and easy method to remove peptide from tag protein.
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Affiliation(s)
- Sivakumar Jeyarajan
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Ansu Susan Peter
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Aswathy Sathyan
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Sukumar Ranjith
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Indira Kandasamy
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Senbagam Duraisamy
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
- Department of Biotechnology, SRM University, Chennai, India
| | | | - Anbarasu Kumarasamy
- Microbial Biotechnology Laboratory, Department of Marine Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
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2
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Peng J, Yang Y, Zhao P, Qiu S, Jia F, Wang J, Liang X, Chaudhry AS, Xu P, Yan W, Xu Z, Wang K. Cu2+ reduces hemolytic activity of the antimicrobial peptide HMPI and enhances its trypsin resistance. Acta Biochim Biophys Sin (Shanghai) 2020; 52:603-611. [PMID: 32369105 DOI: 10.1093/abbs/gmaa043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 11/12/2022] Open
Abstract
Nowadays, drug-resistant microbes are becoming a serious clinical problem threatening people's health and life. Antimicrobial peptides (AMPs) are believed to be potential alternatives of conventional antibiotics to combat the threat of drug-resistant microbes. However, the susceptibility of AMPs toward proteases is one of the major problems limiting their clinical use. In the present study, we reported the effect of Cu2+ on the bioactivity of AMP HMPI. We found that the addition of Cu2+ could improve the protease resistance of AMP HMPI without affecting its bioactivity. Notably, after the binding of Cu2+ with HMPI, the hemolytic activity of HMPI was greatly decreased. In addition, our results also demonstrated that the addition of Cu2+ increased the production of reactive oxygen species in the fungal cells, which may be a supplement for the antifungal activity of HMPI. In conclusion, the introduction of Cu2+ may provide an inorganic strategy to improve the stability and decrease the hemolytic activity of AMP HMPI, while maintaining its antifungal activity.
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Affiliation(s)
- Jinxiu Peng
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yang Yang
- State Key Laboratory of State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China
| | - Ping Zhao
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Shuai Qiu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Fengjing Jia
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jiayi Wang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xiaolei Liang
- Key Laboratory for Gynecologic Oncology of Gansu Province, Department of Gynecology, the First Hospital of Lanzhou University, Lanzhou University, Lanzhou 730000, China
| | - Ahmed Shabbir Chaudhry
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Peihan Xu
- The First Hospital of Lanzhou University, Lanzhou University, Lanzhou 730000, China
| | - Wenjin Yan
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Zhaoqing Xu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Kairong Wang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
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3
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Wang C, Wu J, Li L, Mu C, Lin W. A facile preparation of a novel non-leaching antimicrobial waterborne polyurethane leather coating functionalized by quaternary phosphonium salt. JOURNAL OF LEATHER SCIENCE AND ENGINEERING 2020. [DOI: 10.1186/s42825-019-0014-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
AbstractThe aim of this research is to develop a novel non-leaching antimicrobial waterborne polyurethane (WPU) leather coating material with covalently attached quaternary phosphonium salt (QPS). The structure of the QPS-bearing WPU has been identified, and their thermal stability, mechanical property, and antimicrobial performance have been investigated. The results reveal that the incorporation of QPS slightly reduces the thermal stability of WPU material but would not affects its usability as leather coating. Despite the presence of hydrophobic benzene in QPS structure, the strong hydration of its cationic groups leads to the increased surface contact angle (SCA) and water absorption rate (WAR) of the films, suggesting that the water resistance of the films needs to be improved for the purpose of leather coatings. Antibacterial tests demonstrate that when the QPS content is 20 wt%, QPS-bearing WPU shows effective antimicrobial activity against bacteria. The WPU containing QPS prepared in this study is a non-leaching antimicrobial material and has great potential application as leather coating.
Graphical abstract
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4
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Yadav K, Yavvari PS, Pal S, Kumar S, Mishra D, Gupta S, Mitra M, Soni V, Khare N, Sharma P, Srikanth CV, Kapil A, Singh A, Nandicoori VK, Bajaj A. Oral Delivery of Cholic Acid-Derived Amphiphile Helps in Combating Salmonella-Mediated Gut Infection and Inflammation. Bioconjug Chem 2019; 30:721-732. [DOI: 10.1021/acs.bioconjchem.8b00880] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Kavita Yadav
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
- Manipal Academy of Higher Education, Manipal-576104, Karnataka, India
| | - Prabhu Srinivas Yavvari
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal-462026, Madhya Pradesh, India
| | - Sanjay Pal
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
- Kalinga Institute of Industrial Technology, Bhubaneswar-751024, Odisha India,
| | - Sandeep Kumar
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
- Manipal Academy of Higher Education, Manipal-576104, Karnataka, India
| | - Deepakkumar Mishra
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
| | - Siddhi Gupta
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
| | - Madhurima Mitra
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
| | - Vijay Soni
- National Institute of Immunology, Aruna Asaf Ali
Marg, New Delhi-110067, India
| | - Neha Khare
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
| | - Priyanka Sharma
- Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029, India
| | - Chittur V. Srikanth
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
| | - Arti Kapil
- Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029, India
| | - Archana Singh
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110025, India
| | | | - Avinash Bajaj
- Laboratory of Nanotechnology and Chemical Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Third Milestone, Faridabad-Gurgaon
Expressway, Faridabad-121001, Haryana, India
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5
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Wu ZC, Isley NA, Boger DL. N-Terminus Alkylation of Vancomycin: Ligand Binding Affinity, Antimicrobial Activity, and Site-Specific Nature of Quaternary Trimethylammonium Salt Modification. ACS Infect Dis 2018; 4:1468-1474. [PMID: 30067012 DOI: 10.1021/acsinfecdis.8b00152] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A series of vancomycin derivatives alkylated at the N-terminus amine were synthesized, including those that contain quaternary trimethylammonium salts either directly at the terminal amine site or with an intervening three-carbon spacer. The examination of their properties provides important comparisons with a C-terminus trimethylammonium salt modification that we recently found to improve the antimicrobial potency of vancomycin analogues through an added mechanism of action. The N-terminus modifications disclosed herein were well-tolerated, minimally altering model ligand binding affinities (d-Ala-d-Ala) and antimicrobial activity, but did not induce membrane permeabilization that was observed with a similar C-terminus modification. The results indicate that our earlier observations with the C-terminus modification are sensitive to the site as well as structure of the trimethylammonium salt modification and are not simply the result of nonspecific effects derived from introduction of a cationic charge.
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Affiliation(s)
- Zhi-Chen Wu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nicholas A. Isley
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dale L. Boger
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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6
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Yarlagadda V, Manjunath GB, Sarkar P, Akkapeddi P, Paramanandham K, Shome BR, Ravikumar R, Haldar J. Glycopeptide Antibiotic To Overcome the Intrinsic Resistance of Gram-Negative Bacteria. ACS Infect Dis 2016; 2:132-9. [PMID: 27624964 DOI: 10.1021/acsinfecdis.5b00114] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The emergence of drug resistance along with a declining pipeline of clinically useful antibiotics has made it vital to develop more effective antimicrobial therapeutics, particularly against difficult-to-treat Gram-negative pathogens (GNPs). Many antibacterial agents, including glycopeptide antibiotics such as vancomycin, are inherently inactive toward GNPs because of their inability to cross the outer membrane of these pathogens. Here, we demonstrate, for the first time, lipophilic cationic (permanent positive charge) vancomycin analogues were able to permeabilize the outer membrane of GNPs and overcome the inherent resistance of GNPs toward glycopeptides. Unlike vancomycin, these analogues were shown to have a high activity against a variety of multidrug-resistant clinical isolates such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. In the murine model of carbapenem-resistant A. baumannii infection, the optimized compound showed potent activity with no observed toxicity. The notable activity of these compounds is attributed to the incorporation of new membrane disruption mechanisms (cytoplasmic membrane depolarization along with outer and inner (cytoplasmic) membrane permeabilization) into vancomycin. Therefore, our results indicate the potential of the present vancomycin analogues to be used against drug-resistant GNPs, thus strengthening the antibiotic arsenal for combating Gram-negative bacterial infections.
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Affiliation(s)
- Venkateswarlu Yarlagadda
- Chemical Biology and Medicinal Chemistry
Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Goutham B. Manjunath
- Chemical Biology and Medicinal Chemistry
Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Paramita Sarkar
- Chemical Biology and Medicinal Chemistry
Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Padma Akkapeddi
- Chemical Biology and Medicinal Chemistry
Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Krishnamoorthy Paramanandham
- National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI) Yelahanka, Bengaluru 560064, Karnataka, India
| | - Bibek R. Shome
- National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI) Yelahanka, Bengaluru 560064, Karnataka, India
| | - Raju Ravikumar
- Department of Neuromicrobiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bengaluru 560029, Karnataka, India
| | - Jayanta Haldar
- Chemical Biology and Medicinal Chemistry
Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
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7
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Crisma M, De Zotti M, Formaggio F, Peggion C, Moretto A, Toniolo C. Handedness preference and switching of peptide helices. Part II: Helices based on noncodedα-amino acids. J Pept Sci 2015; 21:148-77. [DOI: 10.1002/psc.2743] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 12/27/2022]
Affiliation(s)
| | - Marta De Zotti
- Department of Chemistry; University of Padova; Padova Italy
| | - Fernando Formaggio
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | | | - Alessandro Moretto
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | - Claudio Toniolo
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
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8
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Yarlagadda V, Akkapeddi P, Manjunath GB, Haldar J. Membrane active vancomycin analogues: a strategy to combat bacterial resistance. J Med Chem 2014; 57:4558-68. [PMID: 24846441 DOI: 10.1021/jm500270w] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The alarming growth of antibiotic resistant superbugs such as vancomycin-resistant Enterococci and Staphylococci has become a major global health hazard. To address this issue, we report the development of lipophilic cationic vancomycin analogues possessing excellent antibacterial activity against several drug-resistant strains. Compared to vancomycin, efficacy greater than 1000-fold was demonstrated against vancomycin-resistant Enterococci (VRE). Significantly, unlike vancomycin, these compounds were shown to be bactericidal at low concentrations and did not induce bacterial resistance. An optimized compound in the series, compared to vancomycin, showed higher activity in methicillin-resistant Staphylococcus aureus (MRSA) infected mouse model and exhibited superior antibacterial activity in whole blood with no observed toxicity. The remarkable activity of these compounds is attributed to the incorporation of a new membrane disruption mechanism into vancomycin and opens up a great opportunity for the development of novel antibiotics.
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Affiliation(s)
- Venkateswarlu Yarlagadda
- Chemical Biology and Medicinal Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bengaluru 560064, Karnataka India
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9
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Libardo MD, Cervantes JL, Salazar JC, Angeles-Boza AM. Improved bioactivity of antimicrobial peptides by addition of amino-terminal copper and nickel (ATCUN) binding motifs. ChemMedChem 2014; 9:1892-901. [PMID: 24803240 DOI: 10.1002/cmdc.201402033] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Indexed: 12/11/2022]
Abstract
Antimicrobial peptides (AMPs) are promising candidates to help circumvent antibiotic resistance, which is an increasing clinical problem. Amino-terminal copper and nickel (ATCUN) binding motifs are known to actively form reactive oxygen species (ROS) upon metal binding. The combination of these two peptidic constructs could lead to a novel class of dual-acting antimicrobial agents. To test this hypothesis, a set of ATCUN binding motifs were screened for their ability to induce ROS formation, and the most potent were then used to modify AMPs with different modes of action. ATCUN binding motif-containing derivatives of anoplin (GLLKRIKTLL-NH2), pro-apoptotic peptide (PAP; KLAKLAKKLAKLAK-NH2), and sh-buforin (RAGLQFPVGRVHRLLRK-NH2) were synthesized and found to be more active than the parent AMPs against a panel of clinically relevant bacteria. The lower minimum inhibitory concentration (MIC) values for the ATCUN-anoplin peptides are attributed to the higher pore-forming activity along with their ability to cause ROS-induced membrane damage. The addition of the ATCUN motifs to PAP also increases its ability to disrupt membranes. DNA damage is the major contributor to the activity of the ATCUN-sh-buforin peptides. Our findings indicate that the addition of ATCUN motifs to AMPs is a simple strategy that leads to AMPs with higher antibacterial activity and possibly to more potent, usable antibacterial agents.
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Affiliation(s)
- M Daben Libardo
- Department of Chemistry, University of Connecticut, Unit 3060, 55 North Eagleville Rd, Storrs, CT 06269 (USA)
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10
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Hoque J, Akkapeddi P, Yarlagadda V, Uppu DSSM, Kumar P, Haldar J. Cleavable cationic antibacterial amphiphiles: synthesis, mechanism of action, and cytotoxicities. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:12225-34. [PMID: 22838496 DOI: 10.1021/la302303d] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The development of novel antimicrobial agents having high selectivity toward bacterial cells over mammalian cells is urgently required to curb the widespread emergence of infectious diseases caused by pathogenic bacteria. Toward this end, we have developed a set of cationic dimeric amphiphiles (bearing cleavable amide linkages between the headgroup and the hydrocarbon tail with different methylene spacers) that showed high antibacterial activity against human pathogenic bacteria (Escherichia coli and Staphylococcus aureus) and low cytotoxicity. The Minimum Inhibitory Concentrations (MIC) were found to be very low for the dimeric amphiphiles and were lower or comparable to the monomeric counterpart. In the case of dimeric amphiphiles, MIC was found to decrease with the increase in the spacer chain length (n = 2 to 6) and again to increase at higher spacer length (n > 6). It was found that the compound with six methylene spacers was the most active among all of the amphiphiles (MICs = 10-13 μM). By fluorescence spectroscopy, fluorescence microscopy, and field-emission scanning electron microscopy (FESEM), it was revealed that these cationic amphiphiles interact with the negatively charged bacterial cell membrane and disrupt the membrane integrity, thus killing the bacteria. All of the cationic amphiphiles showed low hemolytic activity (HC(50)) and high selectivity against both gram-positive and gram-negative bacteria. The most active amphiphile (n = 6) had a 10-13-fold higher HC(50) than did the MIC. Also, this amphiphile did not show any cytotoxicity against mammalian cells (HeLa cells) even at a concentration above the MIC (20 μM). The critical micellar concentration (CMC) values of gemini surfactants were found to be very low (CMC = 0.30-0.11 mM) and were 10-27 times smaller than the corresponding monomeric analogue (CMC = 2.9 mM). Chemical hydrolysis and thermogravimetric analysis (TGA) proved that these amphiphiles are quite stable under both acidic and thermal conditions. Collectively, these properties make the newly synthesized amphiphiles potentially superior disinfectants and antiseptics for various biomedical and biotechnological applications.
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Affiliation(s)
- Jiaul Hoque
- Bioorganic and Medicinal Chemistry Laboratory, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
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