Multienzyme detection and in‐situ monitoring of enzyme activity by bending CE using quantum dots‐based polypeptide substrate

Abstract

Multienzyme detection and monitoring enzyme activity in situ are significant for the disease to diagnose. This study aims to develop a quantum dots (QDs)‐based nanoprobe Cyanine5‐DDDLEVLFQFPGLVPRGSGGHHHHHH‐QDs (Cy5‐LEVLVP‐QD), which is able to detect two enzymes inside a bent capillary using CE. Cy5‐LEVLVP and QDs were allowed to bind with each other through metal affinity interaction and then injected the Cy5‐LEVLVP‐QD complex into a capillary with different bends, followed by related enzyme that can cleave the Cy5‐LEVLVP peptide. The fluorescence of Cy5 was excited by QDs due to Förster resonance energy transfer. By monitoring the peaks produced by the original Cy5‐LEVLVP‐QD complex and a significant fluorescence change, sensitive analysis of two different enzymes was conducted. Therefore, the novel approach of using capillaries with semicircular bends could prove particularly useful for enzyme investigating in disease.

Recent developments in capillary and microchip electroseparations of peptides (2019–mid 2021)

“…Multienzyme detection and in situ monitoring of enzyme activity was implemented using the quantum dots (QDs)‐based polypeptide substrate in the bending CE, that is, CE in capillary with semicircular bends [251]. QDs with attached polypeptide ligand with cleavage sites for two enzymes and CE with Förster resonance energy transfer (FRET) detection allowed assessment of cleavage activity of precision protease and thrombin on the hydrolysis of polypeptide‐QD assembly.…”

Recent advances in nanomaterial‐assisted detection coupled with capillary and microchip electrophoresis

“…Besides DNA fragments, peptides can also be used as arms to link two fluorophores between which FRET occurs. A CE method monitoring the enzyme activities of PreScission protease and thrombin was reported using a capillary with semicircular bends [32]. The peptides DDDLEVLFQFPGLVPRGSGGHHHHHH (LEVLVP) were first labeled with Cyanine5 (Cy5‐LEVLVP), and were immobilized on CdSe/ZnS QDs through a metal affinity interaction (Cy5‐LEVLVP‐QD).…”