Abstract
Dityrosine cross-links are widely observed in nature in structural proteins such as elastin and silk. Natural oxidative cross-linking between tyrosine residues is catalyzed by a diverse group of metalloenzymes. Dityrosine formation is also catalyzed in vitro by metal - peptide complexes such as Gly-Gly-His-Ni(II). On the basis of these observations, a system was developed to specifically and covalently surface immobilize proteins through dityrosine cross-links. Methacrylate monomers of the catalytic peptide Gly-Gly-His-Tyr-OH (GGHY) and the Ni(II)-chelating group nitrilotriacetic acid (NTA) were copolymerized with acrylamide into microbeads. Green fluorescent protein (GFP), as a model protein, was genetically tagged with a tyrosine-modified His 6 peptide on its carboxy terminus. GFP-YGH6, specifically associated with the NTA-Ni(II) groups, was covalently coupled to the bead surface through dityrosine bond formation catalyzed by the colocalized GGHY-Ni(II) complex. After extensive washing with EDTA to disrupt metal coordination bonds, we observed that up to 75% of the initially bound GFP-YGH6 remained covalently bound to the bead while retaining its structure and activity. Dityrosine cross-linking was confirmed by quenching the reaction with free tyrosine. The method may find particular utility in the construction and optimization of protein microarrays.
Original language | English (US) |
---|---|
Pages (from-to) | 11305-11310 |
Number of pages | 6 |
Journal | Langmuir |
Volume | 22 |
Issue number | 26 |
DOIs | |
State | Published - Dec 19 2006 |
Funding
ASJC Scopus subject areas
- Condensed Matter Physics
- Spectroscopy
- General Materials Science
- Surfaces and Interfaces
- Electrochemistry