Synthetic multivalent antifungal peptides effective against fungi.
Taking advantage of the cluster effect observed in multivalent peptides, this work describes antifungal activity and possible mechanism of action of tetravalent peptide (B4010) which carries 4 copies of the sequence RGRKVVRR through a branched lysine core. B4010 displayed better antifungal properties than natamycin and amphotericin B. The peptide retained significant activity in the presence of monovalent/divalent cations, trypsin and serum and tear fluid. Moreover, B4010 is non-haemolytic and non-toxic to mice by intraperitoneal (200 mg/kg) or intravenous (100 mg/kg) routes. S. cerevisiae mutant strains with altered membrane sterol structures and composition showed hyper senstivity to B4010. The peptide had no affinity for cell wall polysaccharides and caused rapid dissipation of membrane potential and release of vital ions and ATP when treated with C. albicans. We demonstrate that additives which alter the membrane potential or membrane rigidity protect C. albicans from B4010-induced lethality. Calcein release assay and molecular dynamics simulations showed that the peptide preferentially binds to mixed bilayer containing ergosterol over phophotidylcholine-cholesterol bilayers. The studies further suggested that the first arginine is important for mediating peptide-bilayer interactions. Replacing the first arginine led to a 2-4 fold decrease in antifungal activities and reduced membrane disruption properties. The combined in silico and in vitro approach should facilitate rational design of new tetravalent antifungal peptides.
Singapore Eye Research Institute, Singapore, Singapore ; Department of Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore.
Rajamani
R
Lakshminarayanan
Singapore Eye Research Institute, Singapore, Singapore ; Department of Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore.
Shouping
S
Liu
Singapore Eye Research Institute, Singapore, Singapore ; Bioinformatics Institute (ASTAR), Singapore, Singapore.
Jianguo
J
Li
Singapore Eye Research Institute, Singapore, Singapore.
Muruganantham
M
Nandhakumar
Singapore Eye Research Institute, Singapore, Singapore.
Thet Tun
TT
Aung
Singapore Eye Research Institute, Singapore, Singapore.
Eunice
E
Goh
Singapore Eye Research Institute, Singapore, Singapore.
Jamie Ya Ting
JY
Chang
Singapore Eye Research Institute, Singapore, Singapore.
Padhmanaban
P
Saraswathi
Department of Pathology, Singapore General Hospital, Singapore, Singapore.
Charles
C
Tang
Singapore Eye Research Institute, Singapore, Singapore.
Siti Radiah Binte
SR
Safie
Singapore Eye Research Institute, Singapore, Singapore.
Lim Yih
LY
Lin
Department of Biochemistry and NCCR Chemical Biology, University of Geneva, Geneva, Switzerland.
Howard
H
Riezman
Singapore Eye Research Institute, Singapore, Singapore ; Department of Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore.
Zhou
Z
Lei
Bioinformatics Institute (ASTAR), Singapore, Singapore ; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore ; Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
Chandra S
CS
Verma
Singapore Eye Research Institute, Singapore, Singapore ; Department of Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School, Singapore, Singapore ; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
Roger W
RW
Beuerman
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology*; D002151:Calorimetry; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002942:Circular Dichroism; D003228:Conjunctiva / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008051:Lipid Bilayers / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008826:Microbial Sensitivity Tests; D056004:Molecular Dynamics Simulation; D010446:Peptide Fragments / Q000737:chemistry* / Q000494:pharmacology*; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects
D000935:Antifungal Agents; D008051:Lipid Bilayers; D010446:Peptide Fragments