title: Antifungal Activity and Action Mechanism of Histatin 5-Halocidin Hybrid Peptides against Candida ssp.
abstract: The candidacidal activity of histatin 5 is initiated through cell wall binding, followed by translocation and intracellular targeting, while the halocidin peptide exerts its activity by attacking the Candida cell membrane. To improve antimicrobial activities and to understand the killing mechanism of two peptides, six hybrid peptides were designed by conjugating histatin 5 and halocidin. A comparative approach was established to study the activity, salt tolerance, cell wall glucan binding assay, cytotoxicity, generation of ROS and killing kinetics. CD spectrometry was conducted to evaluate secondary structures of these hybrid peptides. Furthermore the cellular localization of hybrid peptides was investigated by confocal fluorescence microscopy. Of the six hybrid congeners, di-PH2, di-WP2 and HHP1 had stronger activities than other hybrid peptides against all tested Candida strains. The MIC values of these peptides were 1-2, 2-4 and 2-4 μg/ml, respectively. Moreover, none of the hybrid peptides was cytotoxic in the hemolytic assay and cell-based cytotoxicity assay. Confocal laser microscopy showed that di-PH2 and HHP1 were translocated into cytoplasm whereas di-WP2 was accumulated on surface of C. albicans to exert their candidacidal activity. All translocated peptides (Hst 5, P113, di-PH2) were capable of generating intracellular ROS except HHP1. Additionally, the KFH residues at C-terminal end of these peptides were assumed for core sequence for active translocation.
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, Soonchunhyang University, Cheonan, Chungnam, 31151, South Korea.
authors.forename: Juhye
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, Soonchunhyang University, Cheonan, Chungnam, 31151, South Korea.
authors.forename: Md Anirban
authors.initials: MA
authors.lastname: Jyoti
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, Soonchunhyang University, Cheonan, Chungnam, 31151, South Korea.|Regional Innovation Center, Soonchunhyang University, Asan, Chungnam, 31538, South Korea.
authors.forename: Ho-Yeon
authors.initials: HY
authors.lastname: Song
authors.affiliation: Regional Innovation Center, Soonchunhyang University, Asan, Chungnam, 31538, South Korea.
authors.forename: Woong Sik
authors.initials: WS
authors.lastname: Jang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000494:pharmacology* / Q000633:toxicity; D002175:Candida / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D002473:Cell Wall / Q000378:metabolism; D002942:Circular Dichroism; D003593:Cytoplasm / Q000737:chemistry; D004353:Drug Evaluation, Preclinical; D005936:Glucans / Q000378:metabolism; D054808:Histatins / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D007739:L Cells; D051379:Mice; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D021381:Protein Transport; D017382:Reactive Oxygen Species / Q000378:metabolism; D055049:Salt Tolerance / Q000187:drug effects; D019810:Sodium Azide / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D005936:Glucans; C068075:HTN3 protein, human; D054808:Histatins; D010446:Peptide Fragments; D010455:Peptides; D017382:Reactive Oxygen Species; C460842:halocidin; D019810:Sodium Azide