title: Hydrazino-Pictet-Spengler ligation as a biocompatible method for the generation of stable protein conjugates.
abstract: Aldehyde- and ketone-functionalized biomolecules have found widespread use in biochemical and biotechnological fields. They are typically conjugated with hydrazide or aminooxy nucleophiles under acidic conditions to yield hydrazone or oxime products that are relatively stable, but susceptible to hydrolysis over time. We introduce a new reaction, the hydrazino-Pictet-Spengler (HIPS) ligation, which has two distinct advantages over hydrazone and oxime ligations. First, the HIPS ligation proceeds quickly near neutral pH, allowing for one-step labeling of aldehyde-functionalized proteins under mild conditions. Second, the HIPS ligation product is very stable (>5 days) in human plasma relative to an oxime-linked conjugate (∼1 day), as demonstrated by monitoring protein-fluorophore conjugates by ELISA. Thus, the HIPS ligation exhibits a combination of product stability and speed near neutral pH that is unparalleled by current carbonyl bioconjugation chemistries.
authors.affiliation: Redwood Bioscience, 5703 Hollis Street, Emeryville, California 94608, United States.
authors.forename: Paresh
authors.initials: P
authors.lastname: Agarwal
authors.forename: Romas
authors.initials: R
authors.lastname: Kudirka
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Albers
authors.forename: Robyn M
authors.initials: RM
authors.lastname: Barfield
authors.forename: Gregory W
authors.initials: GW
authors.lastname: de Hart
authors.forename: Penelope M
authors.initials: PM
authors.lastname: Drake
authors.forename: Lesley C
authors.initials: LC
authors.lastname: Jones
authors.forename: David
authors.initials: D
authors.lastname: Rabuka
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D006801:Humans; D006834:Hydrazines / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007659:Ketones / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010091:Oximes / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D001672:Biocompatible Materials; D006834:Hydrazines; D007659:Ketones; D010091:Oximes; D011506:Proteins; C029424:hydrazine