Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2011-5-19
pubmed:abstractText
MX-2401 is a semisynthetic calcium-dependent lipopeptide antibiotic (analogue of amphomycin) in preclinical development for the treatment of serious Gram-positive infections. In vitro and in vivo, MX-2401 demonstrates broad-spectrum bactericidal activity against Gram-positive organisms, including antibiotic-resistant strains. The objective of this study was to investigate the mechanism of action of MX-2401 and compare it with that of the lipopeptide daptomycin. The results indicated that although both daptomycin and MX-2401 are in the structural class of Ca²?-dependent lipopeptide antibiotics, the latter has a different mechanism of action. Specifically, MX-2401 inhibits peptidoglycan synthesis by binding to the substrate undecaprenylphosphate (C??-P), the universal carbohydrate carrier involved in several biosynthetic pathways. This interaction resulted in inhibition, in a dose-dependent manner, of the biosynthesis of the cell wall precursors lipids I and II and the wall teichoic acid precursor lipid III, while daptomycin had no significant effect on these processes. MX-2401 induced very slow membrane depolarization that was observed only at high concentrations. Unlike daptomycin, membrane depolarization by MX-2401 did not correlate with its bactericidal activity and did not affect general membrane permeability. In contrast to daptomycin, MX-2401 had no effect on lipid flip-flop, calcein release, or membrane fusion with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (POPG) liposomes. MX-2401 adopts a more defined structure than daptomycin, presumably to facilitate interaction with C??-P. Mutants resistant to MX-2401 demonstrated low cross-resistance to other antibiotics. Overall, these results provided strong evidence that the mode of action of MX-2401 is unique and different from that of any of the approved antibiotics, including daptomycin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1098-6596
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2743-54
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Mechanism of action and limited cross-resistance of new lipopeptide MX-2401.
pubmed:affiliation
BioWest Therapeutics Inc., Suite 400, 1727 West Broadway, Vancouver, British Columbia V6J4W61, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't