Proteolytic activity at quantum dot-conjugates: kinetic analysis reveals enhanced enzyme activity and localized interfacial "hopping"

Nano Lett. 2012 Jul 11;12(7):3793-802. doi: 10.1021/nl301727k. Epub 2012 Jun 25.

Abstract

Recent studies show that polyvalent, ligand-modified nanoparticles provide significantly enhanced binding characteristics compared to isolated ligands. Here, we assess the ability of substrate-modified nanoparticles to provide enhanced enzymatic activity. Energy transfer assays allowed quantitative, real-time measurement of proteolytic digestion at polyvalent quantum dot-peptide conjugates. Enzymatic progress curves were analyzed using an integrated Michaelis-Menten (MM) formalism, revealing mechanistic details, including deviations from classic MM-behavior. A "hopping" mode of proteolysis at the nanoparticle was identified, confirming enhanced activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cadmium Compounds / chemistry
  • Cattle
  • Fluorescence Resonance Energy Transfer
  • Kinetics
  • Models, Molecular
  • Pancreas / enzymology
  • Peptides / chemistry*
  • Proteolysis*
  • Quantum Dots*
  • Selenium Compounds / chemistry
  • Sulfides / chemistry
  • Trypsin / chemistry
  • Trypsin / metabolism*
  • Zinc Compounds / chemistry

Substances

  • Cadmium Compounds
  • Peptides
  • Selenium Compounds
  • Sulfides
  • Zinc Compounds
  • cadmium selenide
  • Trypsin
  • zinc sulfide