DNA catalysts with tyrosine kinase activity

Area of Science:

• Biochemistry
• Molecular Biology
• Catalysis

Background:

• DNA catalysts (deoxyribozymes) are increasingly recognized for their diverse enzymatic functions.
• Phosphorylation is a critical post-translational modification in biological systems, primarily mediated by protein kinases.

Purpose of the Study:

• To investigate the potential of deoxyribozymes to catalyze the phosphorylation of tyrosine residues in peptides.
• To identify and characterize DNA catalysts capable of tyrosine phosphorylation.

Main Methods:

• In vitro selection was employed to evolve deoxyribozymes from random-sequence DNA pools.
• Peptide substrates with a tyrosine residue were used to screen for phosphorylation activity.
• Enzyme kinetics, including apparent Km, were determined for identified deoxyribozymes.

Main Results:

• Deoxyribozymes capable of transferring a phosphoryl group to tyrosine residues of a hexapeptide were successfully identified.
• These DNA catalysts require specific metal ions, primarily Zn(2+) and often Mn(2+).
• The identified deoxyribozymes exhibit high selectivity for tyrosine over serine phosphorylation and low selectivity for flanking amino acids.

Conclusions:

• DNA possesses the fundamental catalytic ability to phosphorylate tyrosine residues on peptide substrates.
• The discovery of tyrosine kinase deoxyribozymes expands the known repertoire of DNA enzyme functions.
• These findings open possibilities for novel DNA-based catalysts in synthetic biology and biotechnology.