- Novel construction of gold nanoparticle-based peptide chip and assaying enzyme activity and inhibitor effect using secondary ion mass spectrometric analysis thereof

摘要

A gold nanoparticle-based peptide chip, and methods for assaying enzyme activity and enzyme inhibitor effects by using secondary ion mass spectrometric analysis with the same peptide chip are provided to accurately detect the peptide mass through amplification of the secondary ion mass signal by the gold nanoparticle without a marker, and directly measure the enzyme activity. The gold nanoparticle-based peptide chip comprises (A) a support selected from glass, silicon, metal, semiconductor and plastic, (B) a self-assembly monolayer formed on the surface of the support, (C) a gold nanoparticle monolayer formed on the self-assembly monolayer by binding an end group of the self-assembly monolayer to a function group of the gold nanoparticle surface, and (D) a peptide foxed by the gold nanoparticle, wherein the end group of the self-assembly monolayer is selected from amine, thiol, carboxyl, aldehyde, epoxy and maleimide groups, and the surface of the gold nanoparticle is modified with citrate. The method for assaying enzyme activity comprises the steps of: (1) measuring the peptide mass in the gold nanoparticle-based peptide chip by the secondary ion mass spectrometric analysis, (2) reacting an enzyme to be assayed with the gold nanoparticle-based peptide chip; (3) measuring the peptide mass in the gold nanoparticle-based peptide chip of which reaction is completed; and (4) measuring the change of peptide mass by comparing the peptide mass of step(1) with the peptide mass of step(3), wherein the enzyme is kinase, phosphatase, protease, acetylase or methylase.