title: [eta 5-Cyclopentadienyl]metal tricarbonyl pyrylium salts: novel reagents for the specific conjugation of proteins with transition organometallic labels.
abstract: New specific reagents for the conjugation of organo transition metal species to proteins are described. These reagents are pyrylium salts bearing a (eta 5-C5H4)M(CO)3 (M = Mn and Re) at position 4. They couple with simple amines (n-butylamine and tert-butylamine) and to lysine side chains of proteins (bovine serum albumin and lysozyme) with varying yields. In almost all cases, the final conjugated species is a pyridinium salt, with the exception of lysozyme, for which the reaction ends at the divinylogous amide form. Differences in reactivity for bovine serum albumin and lysozyme can be explained in terms of differences of isoelectric point and steric local environment around the reactive lysine residue.
authors.affiliation: Ecole Nationale Supérieure de Chimie de Paris, URA CNRS 403, France.
authors.forename: M
authors.initials: M
authors.lastname: Salmain
authors.forename: K L
authors.initials: KL
authors.lastname: Malisza
authors.forename: S
authors.initials: S
authors.lastname: Top
authors.forename: G
authors.initials: G
authors.lastname: Jaouen
authors.forename: M C
authors.initials: MC
authors.lastname: Sénéchal-Tocquer
authors.forename: D
authors.initials: D
authors.lastname: Sénéchal
authors.forename: B
authors.initials: B
authors.lastname: Caro
mesh_terms: D000097:Acetonitriles; D001888:Boric Acids; D002021:Buffers; D002082:Butylamines / Q000737:chemistry; D007202:Indicators and Reagents; D007526:Isoelectric Point; D008239:Lysine / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: C092362:4-(cyclopentadienyltricarbonylmanganio)-2,6-diphenylpyrylium tetrafluoroborate; C092363:4-(cyclopentadienyltricarbonylrhenio)-2,6-diphenylpyrylium tetrafluoroborate; D000097:Acetonitriles; D001888:Boric Acids; D002021:Buffers; D002082:Butylamines; D007202:Indicators and Reagents; D009942:Organometallic Compounds; D012710:Serum Albumin, Bovine; D009113:Muramidase; D008239:Lysine; C032462:n-butylamine; C032688:boric acid; C032159:acetonitrile