title: Two efficient methods for the conjugation of smooth-form lipopolysaccharides with probes bearing hydrazine or amino groups. II. LPS activation with a cyanopyridinium agent.
abstract: This chapter presents a conjugation method for coupling probes bearing hydrazine or primary amino groups to a lipopolysaccharide (LPS). LPS is modified by the activation of the hydroxyl groups present in its O-antigen moiety with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP). The method yields conjugates with good labeling ratios, preserving the endotoxic activity of the lipid A moiety. Conjugation of smooth-form LPS from Salmonella enterica sv. Minnesota with dansyl hydrazine and horseradish peroxidase yields labeling ratios above 110 nmol dansyl/mg LPS, with nearly no loss of the original endotoxic activity. In the case of horseradish peroxidase, introducing a spacer, a ratio of 29 nmol HRP/mg LPS was obtained, preserving 65% of the original endotoxic activity and an enzymatic activity of 120 U/mg.
authors.affiliation: INQUIMAE - DQIAQF, Universidad de Buenos Aires, C1428EHA, Buenos Aires, Argentina. battagli@qi.fcen.uba.ar
authors.forename: Fernando
authors.initials: F
authors.lastname: Battaglini
authors.forename: Diego
authors.initials: D
authors.lastname: Pallarola
mesh_terms: D000588:Amines / Q000737:chemistry*; D003619:Dansyl Compounds / Q000737:chemistry; D005456:Fluorescent Dyes; D006735:Horseradish Peroxidase / Q000378:metabolism; D006834:Hydrazines / Q000737:chemistry*; D008050:Lipid A / Q000032:analysis*; D009570:Nitriles / Q000737:chemistry*; D019081:O Antigens / Q000737:chemistry; D011726:Pyridinium Compounds / Q000737:chemistry*; D019779:Salmonella enterica / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D000588:Amines; D003619:Dansyl Compounds; D005456:Fluorescent Dyes; D006834:Hydrazines; D008050:Lipid A; D009570:Nitriles; D019081:O Antigens; D011726:Pyridinium Compounds; C029424:hydrazine; C027913:dansyl hydrazine; C067292:1-cyano-4-dimethylaminopyridinium; D006735:Horseradish Peroxidase