Design of an electroactive peptide probe for sensing of a protein.
We designed a new electroactive peptide probe that has a molecular recognition function for the sensing of a protein. Ovalbumin (OVA) was the model protein, and when RNRCKGTDVQAW interacted with OVA, it conjugated with a tyrosine-rich peptide (Y4C). This peptide is electroactive, has a high degree of biocompatibility, and offers the possibility of gene expression. To measure the effect of a number of the tyrosine residues, voltammetric measurements were conducted using a series of tyrosine-rich peptides (YnC, n = 3-7) with sensitivities that ranged from 10(-9) to 10(-8) M. The electrode response of Y5C was the maximum value in the series. However, the peak current did not increase when the number of tyrosine residues was increased in a linear fashion. This may have been due to the micelles that are formed by a tyrosine-rich surfactant peptide. Thus, Y4C was suitable as an electroactive label for the construction of the peptide probe. The electrode response of Y4CRNRCKGTDVQAW obtained by a glassy carbon electrode was 100-fold that of tyrosine alone. The measurement of OVA via the peptide probe resulted in a detection on the order of 10(-12) M. In contrast, the sensitivity of OVA using RCKGTDVQAWY4C probe was at the 10(-11) M level, because the hydrophobic moiety gave it a molecular recognition function. The recoveries of the OVA using Y4CRNRCKGTDVQAW in a solution containing fetal bovine serum ranged between 98 and 101%. Consequently, the combination of a specific peptide and an electroactive element could be a powerful probe for the sensing of proteins.
Maebashi Institute of Technology, Gunma 371-0816, Japan.
Hiroki
H
Shinohara
Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Toyama 930-8555, Japan.
Hideki
H
Kuramitz
Maebashi Institute of Technology, Gunma 371-0816, Japan. Electronic address: kzsuga@maebashi-it.ac.jp.
Kazuharu
K
Sugawara
D000595:Amino Acid Sequence; D000818:Animals; D002244:Carbon / Q000737:chemistry; D002417:Cattle; D055664:Electrochemical Techniques; D004566:Electrodes; D057927:Hydrophobic and Hydrophilic Interactions; D015335:Molecular Probes / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D010047:Ovalbumin / Q000032:analysis*; D010084:Oxidation-Reduction; D044967:Serum / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry
D015335:Molecular Probes; D009842:Oligopeptides; D014443:Tyrosine; D002244:Carbon; D010047:Ovalbumin
Oligotyrosine; Ovalbumin; Protein-peptide binding; Tyrosine-rich peptide; Voltammetry