title: Site-specific and stoichiometric conjugation of cationic porphyrins to antiangiogenic monoclonal antibodies.
abstract: Synthesis of three new cationic thiol-reactive maleimide-porphyrin derivatives and their use in site-specific conjugation to monoclonal antibodies is reported. The selective reactivity toward thiols is demonstrated using competition experiments, where both thiols and amines are present. This selectivity was used to successfully achieve specific conjugation of two porphyrins to cysteine residues present in the antiangiogenic antibody L19, expressed in small immunoprotein (SIP) format. The effect of length and hydrophilicity of the linkage between porphyrin and maleimide was also investigated, and maximum photocytotoxicity was achieved with the longest and most hydrophilic chain. Immunoreactivity and in vitro photocytotoxicity for these well-characterized porphyrin-antibody conjugates are described.
authors.affiliation: Department of Chemistry, University of Hull, Cottingham Road, HU6 7RX, Kingston-upon-Hull, United Kingdom.
authors.forename: Cristina M A
authors.initials: CM
authors.lastname: Alonso
authors.forename: Alessandro
authors.initials: A
authors.lastname: Palumbo
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Bullous
authors.forename: Francesca
authors.initials: F
authors.lastname: Pretto
authors.forename: Dario
authors.initials: D
authors.lastname: Neri
authors.forename: Ross W
authors.initials: RW
authors.lastname: Boyle
mesh_terms: D000588:Amines / Q000737:chemistry; D020533:Angiogenesis Inhibitors / Q000737:chemistry*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D001665:Binding Sites; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D018796:Immunoconjugates / Q000737:chemistry; D007162:Immunoproteins / Q000737:chemistry; D008301:Maleimides / Q000737:chemistry; D010084:Oxidation-Reduction; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry*; D012995:Solubility; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000588:Amines; D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D018796:Immunoconjugates; D007162:Immunoproteins; D008301:Maleimides; D017319:Photosensitizing Agents; D011166:Porphyrins; D013438:Sulfhydryl Compounds; D014867:Water; C043592:maleimide