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Kanemitsu S, Morita K, Tominaga Y, Nishimura K, Yashiro T, Sakurai H, Yamamoto Y, Kurisaki I, Tanaka S, Matsui M, Ooya T, Tamura A, Maruyama T. Inhibition of Melittin Activity Using a Small Molecule with an Indole Ring. J Phys Chem B 2022; 126:5793-5802. [PMID: 35913127 DOI: 10.1021/acs.jpcb.2c03595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated d-amino acids as potential inhibitors targeting l-peptide toxins. Among the l- and d-amino acids tested, we found that d-tryptophan (d-Trp) acted as an inhibitor of melittin-induced hemolysis. We then evaluated various Trp derivatives and found that 5-chlorotryptamine (5CT) had the largest inhibitory effect on melittin. The indole ring, amino group, and steric hindrance of an inhibitor played important roles in the inhibition of melittin activity. Despite the small size and simple molecular structure of 5CT, its IC50 was approximately 13 μg/mL. Fluorescence quenching, circular dichroism measurements, and size-exclusion chromatography revealed that 5CT interacted with Trp19 in melittin and affected the formation of the melittin tetramer involved in hemolysis. Molecular dynamics simulation of melittin also indicated that the interaction of 5CT with Trp19 in melittin affected the formation of the tetramer.
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Affiliation(s)
- Sayuki Kanemitsu
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Kenta Morita
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Yudai Tominaga
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Kanon Nishimura
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Tomoko Yashiro
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Haruka Sakurai
- Graduate School of Science, Department of Chemistry, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Yumemi Yamamoto
- Graduate School of Science, Department of Chemistry, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Ikuo Kurisaki
- Department of Computational Science, Graduate School of System Informatics, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Shigenori Tanaka
- Department of Computational Science, Graduate School of System Informatics, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Masaki Matsui
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Tooru Ooya
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Atsuo Tamura
- Graduate School of Science, Department of Chemistry, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Tatsuo Maruyama
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.,Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
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Jamasbi E, Ciccotosto GD, Tailhades J, Robins-Browne RM, Ugalde CL, Sharples RA, Patil N, Wade JD, Hossain MA, Separovic F. Site of fluorescent label modifies interaction of melittin with live cells and model membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2031-9. [PMID: 26051124 DOI: 10.1016/j.bbamem.2015.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 05/30/2015] [Accepted: 06/02/2015] [Indexed: 02/01/2023]
Abstract
The mechanism of membrane disruption by melittin (MLT) of giant unilamellar vesicles (GUVs) and live cells was studied using fluorescence microscopy and two fluorescent synthetic analogues of MLT. The N-terminus of one of these was acylated with thiopropionic acid to enable labeling with maleimido-AlexaFluor 430 to study the interaction of MLT with live cells. It was compared with a second analogue labeled at P14C. The results indicated that the fluorescent peptides adhered to the membrane bilayer of phosphatidylcholine GUVs and inserted into the plasma membrane of HeLa cells. Fluorescence and light microscopy revealed changes in cell morphology after exposure to MLT peptides and showed bleb formation in the plasma membrane of HeLa cells. However, the membrane disruptive effect was dependent upon the location of the fluorescent label on the peptide and was greater when MLT was labeled at the N-terminus. Proline at position 14 appeared to be important for antimicrobial activity, hemolysis and cytotoxicity, but not essential for cell membrane disruption.
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Affiliation(s)
- Elaheh Jamasbi
- School of Chemistry, Bio21 Institute, The University of Melbourne, VIC 3010, Australia
| | | | - Julien Tailhades
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, VIC 3010, Australia
| | - Roy M Robins-Browne
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, VIC 3010, Australia; Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Cathryn L Ugalde
- Department of Biochemistry & Molecular Biology, Bio21 Institute, The University of Melbourne, VIC 3010, Australia
| | - Robyn A Sharples
- Department of Biochemistry & Molecular Biology, Bio21 Institute, The University of Melbourne, VIC 3010, Australia
| | - Nitin Patil
- School of Chemistry, Bio21 Institute, The University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, VIC 3010, Australia
| | - John D Wade
- School of Chemistry, Bio21 Institute, The University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, VIC 3010, Australia
| | - Mohammed Akhter Hossain
- School of Chemistry, Bio21 Institute, The University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, VIC 3010, Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Institute, The University of Melbourne, VIC 3010, Australia
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Ningsih Z, Hossain MA, Wade JD, Clayton AHA, Gee ML. Slow insertion kinetics during interaction of a model antimicrobial peptide with unilamellar phospholipid vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:2217-2224. [PMID: 22148887 DOI: 10.1021/la203770j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The mechanism of interaction between a model antimicrobial peptide and phospholipid unilamellar vesicle membranes was studied using fluorescence spectroscopy, fluorescence lifetime measurements, and light scattering. The peptide, a mellitin mutant, was labeled at position K14 with the polarity-sensitive probe AlexaFluor 430. The kinetics of the interaction of this derivative with various concentrations of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) vesicles was examined. Our work unveiled two novel aspects of peptide-lipid interactions. First, the AB plot or phasor analysis of the fluorescence lifetime studies revealed at least three different peptide states, the population of which depended on the lipid to peptide (L:P) concentration ratio. Second, complex fluorescence kinetics were observed over extended time-scales from 30 s to 2 h. The extended kinetics was only observed at particular lipid concentrations (L:P ratios 20:1 and 10:1) and not at others (30, 40, 50 and 100:1 L:P ratio). Analysis of the complex kinetics revealed several intermediates. We assign these to distinct states of the peptide formed during helix insertion into the vesicle membrane that are intermediate to lytic pore formation.
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Affiliation(s)
- Zubaidah Ningsih
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
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