Abstract
Enduracidins (1, 2) and ramoplanin (3) are structurally and functionally closely related lipodepsipeptide antibiotics. They are active against multi-drug-resistant Gram-positive pathogens, including MRSA. Each peptide contains one chlorinated non-proteinogenic amino acid residue, Cl 2-Hpg or Cl-Hpg. To investigate the timing of halogenation and the importance of chlorination on bioactivity and bioavailability of enduracidin, and to probe the substrate specificity and portability of the ramoplanin halogenase, we constructed the mutant strain SfΔ30 in which the enduracidin halogenase gene orf30 had been deleted and complemented it with the ramoplanin counterpart orf20. We also expressed orf20 in the enduracidin wild-type producer. Metabolite analysis revealed SfΔ30 produced the novel analogues dideschloroenduracidins A (4) and B (5), while the recombinant strains Sf?30R20 and SfR20 produced monodeschloroenduracidins A (6) and B (7) and a trichlorinated enduracidin (8), respectively. In addition, orf30 self-complementation yielded the strain Sf?30E30, which is capable of producing six peptides including 6 and 7. MS/MS analysis positioned the single chlorine atom in 6 at Hpg13 and localized the third chlorine atom in 8 to Hpg11. Biological evaluation of these enduracidin analogues indicated that all retained activity against Staphylococcus aureus. Our findings lay the foundation for further utilization of enduracidin and ramoplanin halogenases in combinatorial biosynthesis.
Original language | English (US) |
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Pages (from-to) | 583-589 |
Number of pages | 7 |
Journal | Journal of Natural Products |
Volume | 73 |
Issue number | 4 |
DOIs | |
State | Published - Apr 23 2010 |
Externally published | Yes |
ASJC Scopus subject areas
- Analytical Chemistry
- Molecular Medicine
- Pharmacology
- Pharmaceutical Science
- Drug Discovery
- Complementary and alternative medicine
- Organic Chemistry