title: Hydroxyproline substitutions stabilize non-glycosylated drosocin against serum proteases without challenging its antibacterial activity.
abstract: The increasing incidence of multi- and pan-resistant pathogens demands novel compounds to fight Grampositive and especially Gram-negative bacteria. Among the currently investigated compound classes, antimicrobial peptides (AMPs) inhibiting specific bacterial targets appear especially promising for systemic therapy of infections, although unmodified linear peptides are typically rapidly degraded by serum proteases. Proline-rich AMPs have been heavily investigated in recent years due to their low toxicity and proven in vivo efficacy. Here, we report novel unglycosylated drosocin analogs with extended half-life in mouse serum and improved activity against Gram-negative pathogens Escherichia coli and Klebsiella pneumoniae. Substituting proline (Pro) residues in positions 3, 5, 10, and 14 with trans-4-hydroxy-Lproline ((t)Hyp) improved the antibacterial activity, whereas substitution of Pro-16 reduced the activity. Drosocin analogs with (t)Hyp in positions 3 and 5 were also four to eight times more stable in mouse serum than the unmodified analog. The new compounds were not toxic against human HeLa, HEK293, and HepG2 cell lines and showed no hemolytic activity against human erythrocytes at peptide concentrations of at least 600 µg/mL.
authors.forename: Daniel
authors.initials: D
authors.lastname: Knappe
authors.forename: Marco
authors.initials: M
authors.lastname: Cassone
authors.forename: Friederike Inga
authors.initials: FI
authors.lastname: Nollmann
authors.forename: Laszlo
authors.initials: L
authors.lastname: Otvos
authors.affiliation: Institut fur Bioanalytische Chemie, Biotechnologisch-Biomedizinisches Zentrum, Universitat Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany. daniel.knappe@bbz.uni-leipzig.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D002460:Cell Line; D004355:Drug Stability; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000188:drug therapy; D006020:Glycopeptides / Q000097:blood / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D006031:Glycosylation; D006207:Half-Life; D006801:Humans; D006909:Hydroxyproline / Q000737:chemistry*; D007710:Klebsiella Infections / Q000188:drug therapy; D007711:Klebsiella pneumoniae / Q000187:drug effects; D051379:Mice; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000097:blood / Q000378:metabolism*; D010455:Peptides / Q000097:blood / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D010455:Peptides; C082117:drosocin; D010447:Peptide Hydrolases; D006909:Hydroxyproline