title: Specific interaction of jacalin with phycocyanin, a fluorescent phycobiliprotein.
abstract: Recent research has shown that, like porphyrins, phycocyanin (PC) too can produce singlet oxygen upon excitation with the appropriate radiation and hence could be useful in photodynamic therapy (PDT) for cancer. Unlike porphyrins, PC has the advantage of being a non-toxic, non-carcinogenic, soluble protein. However, the challenge would be to target the fluorescent phycobiliprotein to malignant cells. We report here that the tumor-specific lectin, jacalin, binds PC specifically in a carbohydrate-independent manner and with affinities better than that for porphyrins. Hence the lectin could prove to be a useful carrier for targeted delivery of PC. The interaction involves both ionic and hydrophobic interactions and more than one contact site.
authors.affiliation: Department of Bio-Sciences, Jamia Millia Islamia, New Delhi 110 025, India.
authors.forename: Gunjan
authors.initials: G
authors.lastname: Pandey
authors.forename: Tasneem
authors.initials: T
authors.lastname: Fatma
authors.forename: Sudha M
authors.initials: SM
authors.lastname: Cowsik
authors.forename: Sneha Sudha
authors.initials: SS
authors.lastname: Komath
mesh_terms: D005453:Fluorescence; D057927:Hydrophobic and Hydrophilic Interactions; D010778:Photochemotherapy; D052979:Phycobiliproteins / Q000737:chemistry*; D010798:Phycocyanin / Q000737:chemistry*; D037121:Plant Lectins / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D052979:Phycobiliproteins; D037121:Plant Lectins; C043696:jacalin; D010798:Phycocyanin; D026082:Singlet Oxygen