Assessing histidine tags for recruiting deoxyribozymes to catalyze peptide and protein modification reactions

Abstract

We evaluate the ability of hexahistidine (His6) tags on peptide and protein substrates to recruit deoxyribozymes for modifying those substrates. For two different deoxyribozymes, one that creates tyrosine-RNA nucleopeptides and another that phosphorylates tyrosine side chains, we find substantial improvements in yield, kobs, and Km for peptide substrates due to recruiting by His6/Cu2+. However, the recruiting benefits of the histidine tag are not observed for larger protein substrates, likely because the tested deoxyribozymes either cannot access the target peptide segments or cannot function when these segments are presented in a structured protein context.

Tyrosine bioconjugation – an emergent alternative

“…This arrangement would bring the substrate and the catalyst into close proximity 60 via binding of divalent metal ions (e.g. Cu 2+ ) to both the His 6 and NTA (Scheme 8b).…”

“…A slightly different approach used a hexahistidine tag (His 6 ) on the untethered peptide 46 in combination with a DNA anchor complementary to part of the deoxyribozyme and linked to three nitrilotriacetic acid (NTA) units 47 . This arrangement would bring the substrate and the catalyst into close proximity 60 via binding of divalent metal ions ( e.g. Cu 2+ ) to both the His 6 and NTA ( Scheme 8b ).…”

DNA‐Catalyzed Introduction of Azide at Tyrosine for Peptide Modification

“…In ongoing work, we are seeking to combine the key features of peptide sequence selectivity (for example, DzAz2) and reactivity with free peptide substrates (for example, DzAz8). We are also seeking to extend DNA‐catalyzed reactivity from peptides to larger protein substrates …”

“…We are also seeking to extend DNA-catalyzed reactivity from peptides to larger protein substrates. [19] …”

DNA‐Catalyzed Introduction of Azide at Tyrosine for Peptide Modification

“…We are also seeking to extend DNAcatalyzed reactivity from peptides to larger protein substrates. [19] Keywords: deoxyribozymes ·DNA ·invitro selection · peptide modification ·p eptides Figure 5. DzAz2 differentiates between two Tyrinone peptide substrate.…”