Site-Specific Protein Modification with a Dirhodium Metallopeptide Catalyst

Abstract

A new method for chemical protein modification is presented utilizing a dirhodium metallopeptide catalyst. The combination of peptide-based molecular recognition and a dirhodium catalyst with broad side-chain scope enables site-specific protein functionalization. The scope and utility of dirhodium-catalyzed biomolecule modification is expanded to allow reaction at physiological pH and in biologically relevant buffer solutions. Specific protein modification is possible directly in E. coli lysate, demonstrating the remarkable activity and specificity of the designed metallopeptide catalyst. Furthermore, a new biotin-diazo conjugate 1b is presented that allows affinity tagging of target proteins.

Click Chemistry in Complex Mixtures: Bioorthogonal Bioconjugation

“…The Francis lab has developed a tryptophan modification using rhodium carbenoids in aqueous solution (Antos and Francis, 2004) over a broad pH range (entry 3) (Antos et al, 2009). This rhodium catalysis has been applied to site-specific modification of aromatic side chains (Trp, Tyr and Phe) using metallopeptides capable of molecular recognition (Antos et al, 2009; Chen et al, 2011). …”

Selective N-terminal functionalization of native peptides and proteins

“…1 Due to the wide applications, a series of selective modification methods 2 have been developed to modify lysines, 3 cysteines, 1b,2f,g,4 tyrosines, 5 tryptophans 6 or N-termini. 7–10 Among these positions, the N-terminus position is an appealing target because there is generally only one such group in a single-chain peptide or protein.…”

Designing Enzyme-Like Catalysts: A Rhodium(II) Metallopeptide Case Study

“…In totality, residues identified as substrates for modification make up >40% of protein amino-acid space. The reactivity demonstrated here enabled a number of studies with similar engineered coils, including design of orthogonally reactive catalyst-substrate [10] pairs and the use of tryptophan-containing coils as tags for proteins expressed in lysate [10,11].…”