title: Synthesis and biological evaluation of biotinyl hydrazone derivatives of muramyl peptides.
abstract: Muramyl peptides derived from bacterial peptidoglycan have long been known for their ability to trigger host innate immune responses, including inflammation and antimicrobial defense. Muramyl peptides have also been widely studied for their role as immune adjuvants. In mammals, the nucleotide-binding oligomerization domain (Nod) proteins Nod1 and Nod2 detect distinct muramyl peptide structures and mediate their biological activity. Because of the poor immunogenicity of these small peptidoglycan derivatives, research in this field is currently limited by the lack of reagents to track or immobilize specific muramyl peptides. We present here the generation and initial biological characterization of synthetic muramyl peptides covalently coupled to dansyl or biotinyl derivatives and demonstrate that biotinyl coupling on the muramyl moiety results in derivatives that can be tracked by immunofluorescence and maintain full biological activity, as observed by their capacity to trigger Nod signaling. Moreover, using digitonin-mediated permeabilization techniques on live cells, we also demonstrate that biotinylated muramyl peptides efficiently reach the host cytosol, where they activate Nod signaling. Therefore, these derivatives represent useful probes to study the cell biology and the biochemistry of host responses to muramyl peptides.
authors.affiliation: Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Univ. Paris-Sud, Orsay, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Blanot
authors.forename: Jooeun
authors.initials: J
authors.lastname: Lee
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Girardin
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D000276:Adjuvants, Immunologic / Q000494:pharmacology; D001710:Biotin / Q000737:chemistry*; D002460:Cell Line; D003619:Dansyl Compounds / Q000737:chemistry; D004072:Digitonin / Q000737:chemistry; D006801:Humans; D006835:Hydrazones / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D053474:Nod1 Signaling Adaptor Protein / Q000737:chemistry / Q000378:metabolism; D053473:Nod2 Signaling Adaptor Protein / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000276:Adjuvants, Immunologic; D003619:Dansyl Compounds; D006835:Hydrazones; D016328:NF-kappa B; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D000119:Acetylmuramyl-Alanyl-Isoglutamine; D001710:Biotin; D004072:Digitonin; C029038:dansyl chloride