title: Synthesis and antimicrobial activity of cysteine-free coprisin nonapeptides.
abstract: Coprisin is a 43-mer defensin-like peptide from the dung beetle, Copris tripartitus. CopA3 (LLCIALRKK-NH₂), a 9-mer peptide containing a single free cysteine residue at position 3 of its sequence, was derived from the α-helical region of coprisin and exhibits potent antibacterial and anti-inflammatory activities. The single cysteine implies a tendency for dimerization; however, it remains unknown whether this cysteine residue is indispensible for CopA3's antimicrobial activity. To address this issue, in the present study we synthesized eight cysteine-substituted monomeric CopA3 analogs and two dimeric analogs, CopA3 (Dimer) and CopIK (Dimer), and evaluated their antimicrobial effects against bacteria and fungi, as well as their hemolytic activity toward human erythrocytes. Under physiological conditions, CopA3 (Mono) exhibits a 6/4 (monomer/dimer) molar ratio in HPLC area percent, indicating that its effects on bacterial strains likely reflect a CopA3 (Mono)/CopA3 (Dimer) mixture. We also report the identification of CopW, a new cysteine-free nonapeptide derived from CopA3 that has potent antimicrobial activity with virtually no hemolytic activity. Apparently, the cysteine residue in CopA3 is not essential for its antimicrobial function. Notably, CopW also exhibited significant synergistic activity with ampicillin and showed more potent antifungal activity than either wild-type coprisin or melittin.
authors: School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712, Republic of Korea.
authors: Jaeho
authors: J
authors: Lee
authors: School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712, Republic of Korea.
authors: Daeun
authors: D
authors: Lee
authors: School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu 702-701, Republic of Korea.
authors: Hyemin
authors: H
authors: Choi
authors: College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea.
authors: Ha Hyung
authors: HH
authors: Kim
authors: School of Life Sciences and Biotechnology, College of Natural Science, Daejin University, Pocheon, Gyeonggido, Republic of Korea.
authors: Ho
authors: H
authors: Kim
authors: Department of Agricultural Biology, Natural Academy of Agricultural Science, RDA, Suwon 441-853, Republic of Korea.
authors: Jae Sam
authors: JS
authors: Hwang
authors: School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu 702-701, Republic of Korea.
authors: Dong Gun
authors: DG
authors: Lee
authors: School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712, Republic of Korea. Electronic address: jikim@gist.ac.kr.
authors: Jae Il
authors: JI
authors: Kim
mesh_terms: D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000494:pharmacology; D001419:Bacteria / Q000166:cytology / Q000187:drug effects*; D018407:Bacterial Physiological Phenomena / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D003545:Cysteine / Q000737:chemistry*; D005658:Fungi / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D019476:Insect Proteins / Q000138:chemical synthesis* / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D019476:Insect Proteins; C570442:coprisin peptide, Copris tripartitus; D003545:Cysteine
keywords: AMP; ATCC; American Type Culture Collection; Antimicrobial activity; Antimicrobial peptide; CLSI; Clinical and Laboratory Standards Institute; Cysteine-free coprisin; HPLC; KCTC; Korean Collection for Type Cultures; LPS; Nonapeptide; PBS; Synergic effect; antimicrobial peptide; high performance liquid chromatography; lipopolysaccharide; phosphate buffered saline