Monolithic Peptide-Nucleic Acid Hybrid Functioning as an Artificial Microperoxidase

Bioconjug Chem. 2017 Aug 16;28(8):2031-2034. doi: 10.1021/acs.bioconjchem.7b00216. Epub 2017 Jul 25.

Abstract

A new peptide nucleic acid (PNA) with an installed peroxidase function has been developed. Fmoc solid phase peptide synthesis prepared a PNA hybrid (VQKCAQCHTVE-(C2H4O)2CH2-[PNA(T)]6-G) that renders the microperoxidase backbone, followed by reconstitution with hemin. The resulting holocompound catalyzed the oxidation of 3,3',5,5'-tetramthylbenzidine by H2O2 to 50% that of natural microperoxidase-11, whereas the apo-form and hemin gave no responses. The peroxidase domain was found to be active toward direct electrochemistry and the PNA hybrid served for gene sensor; in the presence of the target DNA (5'-CATGTATAAAAAA-3'), an electrode-attached DNA probe (5'-TsTsTsTsTsTCTCATACATG-3') showed the ferric-to-ferrous quasi-reversible wave (-276 mV vs Ag/AgCl) through sandwich hybridization. Moreover, the hybridization product could accept H2O2 as an oxidant to enhance the reduction current, which occurred likely based on the iron(II)-center-recycling with specific rate constant of 0.19 s-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Biomimetic Materials / chemistry*
  • Biomimetic Materials / metabolism*
  • Models, Molecular
  • Peptide Nucleic Acids / chemistry*
  • Peptide Nucleic Acids / metabolism*
  • Peroxidases / metabolism*
  • Protein Conformation

Substances

  • Peptide Nucleic Acids
  • Peroxidases
  • microperoxidase