title: Rapid catalyst-free hydrazone ligation: protein-pyridoxal phosphoramides.
abstract: Pyridoxal-5'-phosphate (PLP) represents an active form of Vitamin B(6) that shows relatively fast imine formation with hydrazines under physiological conditions without the need of a catalyst. A convenient phosphate/amine conjugation protocol was developed to covalently link PLP to proteins, affording proteins capable of hydrazone formation with bioorthogonal hydrazinyl functional groups. Thus, the lectin Concanavalin A (Con A) was labeled with PLP. Pretreatment with fluorescein hydrazide gave dye-labeled Con A that labeled cell surfaces efficiently. Alternatively, pretargeting was achieved by labeling cells with Con A-PLP, then treatment in vitro with Alexa Fluor 488 hydrazide.
authors.affiliation: Department of Chemistry, New York University, New York, NY 10003, USA.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Wang
authors.forename: James W
authors.initials: JW
authors.lastname: Canary
mesh_terms: D002460:Cell Line; D003208:Concanavalin A / Q000737:chemistry*; D004847:Epithelial Cells / Q000737:chemistry; D005452:Fluoresceins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D006834:Hydrazines / Q000737:chemistry; D006835:Hydrazones / Q000138:chemical synthesis*; D007202:Indicators and Reagents / Q000737:chemistry; D015394:Molecular Structure; D063088:Phosphoramides / Q000138:chemical synthesis*; D011732:Pyridoxal Phosphate / Q000737:chemistry*; D013194:Staining and Labeling / Q000379:methods*
chemical_list: C417561:Alexa 488 hydrazide; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006834:Hydrazines; D006835:Hydrazones; D007202:Indicators and Reagents; D063088:Phosphoramides; C052067:fluorescein hydrazide; D003208:Concanavalin A; D011732:Pyridoxal Phosphate