title: Spectroscopic investigation on the interaction of ruthenium complexes with tumor specific lectin, jacalin.
abstract: Several ruthenium complexes are regarded as anticancer agents and considered as an alternative to the widely used platinum complexes. Owing to the preferential interaction of jacalin with tumor-associated T-antigen, we report the interaction of jacalin with four ruthenium complex namely, tris(1,10-phenanthroline)ruthenium(II)chloride, bis(1,10-phenanthroline)(N-[1,10]phenanthrolin-5-yl-pyrenylmethanimine)ruthenium(II)chloride, bis(1,10-phenanthroline)(dipyrido[3,2-a:2',3'-c]-phenazine)ruthenium(II)chloride, bis(1,10-phenanthroline)(11-(9-acridinyl)dipyrido[3,2-a:2',3'-c]phenazine)ruthenium(II) chloride. Fluorescence spectroscopic analysis revealed that the ruthenium complexes strongly quenched the intrinsic fluorescence of jacalin through a static quenching procedure, and a non-radiative energy transfer occurred within the molecules. Association constants obtained for the interaction of different ruthenium complexes with jacalin are in the order of 10(5) M(-1), which is in the same range as those obtained for the interaction of lectin with carbohydrate and hydrophobic ligand. Each subunit of the tetrameric jacalin binds one ruthenium complex, and the stoichiometry is found to be unaffected by the presence of the specific sugar, galactose. In addition, agglutination activity of jacalin is largely unaffected by the presence of the ruthenium complexes, indicating that the binding sites for the carbohydrate and the ruthenium complexes are different. These results suggest that the development of lectin-ruthenium complex conjugate would be feasible to target malignant cells in chemo-therapeutics.
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thirumalaisamudaram, Thanjavur, Tamil Nadu, India.
authors.forename: Khan Behlol
authors.initials: KB
authors.lastname: Ayaz Ahmed
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thirumalaisamudaram, Thanjavur, Tamil Nadu, India.
authors.forename: Elamvazhuthi
authors.initials: E
authors.lastname: Reshma
authors.affiliation: Department of Chemistry, SRM University, Kattankulathur, Chennai, Tamil Nadu, India.
authors.forename: Mariappan
authors.initials: M
authors.lastname: Mariappan
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thirumalaisamudaram, Thanjavur, Tamil Nadu, India. Electronic address: anbazhagan@scbt.sastra.edu.
authors.forename: Veerappan
authors.initials: V
authors.lastname: Anbazhagan
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism; D031622:Artocarpus / Q000737:chemistry*; D001665:Binding Sites; D056831:Coordination Complexes / Q000737:chemistry* / Q000378:metabolism; D010618:Phenanthrolines / Q000737:chemistry / Q000378:metabolism; D037121:Plant Lectins / Q000737:chemistry* / Q000378:metabolism; D012428:Ruthenium / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D000970:Antineoplastic Agents; D056831:Coordination Complexes; D010618:Phenanthrolines; D037121:Plant Lectins; C043696:jacalin; D012428:Ruthenium; C025205:1,10-phenanthroline
keywords: Binding constant; Fluorescence quenching; Jacalin; Lectin; Polypyridyl ruthenium (II)