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Functionalized graphene oxide in enzyme engineering: a selective modulator for enzyme activity and thermostability
Liling Jin1, Kai Yang, Kai Yao
1Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
ACS Nano
|May 12, 2012
Summary
Functionalized graphene oxide (GO) selectively enhances serine protease activity, particularly trypsin, by up to 43-fold for specific substrates. This discovery offers new potential for enzyme engineering and biosensing applications.
Area of Science:
- Nanobiotechnology
- Materials Science
- Biochemistry
Background:
- Understanding nanomaterial-biomolecule interactions is crucial for nanobiotechnology.
- Graphene oxide (GO) is a 2-D nanomaterial with broad biomedical applications.
- Interactions between functionalized GO and enzymes remain underexplored.
Purpose of the Study:
- Investigate interactions between serine proteases and amine-terminated polyethylene glycol (PEG)-functionalized GO.
- Explore the potential of functionalized GO in enzyme engineering.
- Analyze the effects on trypsin, chymotrypsin, and proteinase K.
Main Methods:
- Functionalization of GO with amine-terminated PEG.
- Enzyme activity and thermostability assays using trypsin, chymotrypsin, and proteinase K.
- Substrate-dependent activity analysis and mechanistic investigation.
Main Results:
- PEGylated GO selectively enhanced trypsin activity and thermostability (60-70% retained activity at 80 °C).
- No significant effect observed on chymotrypsin or proteinase K.
- Activity enhancement was substrate-dependent, specifically on phosphorylated substrates, with up to a 43-fold increase.
- Mechanism attributed to PEG terminal amino groups and GO's 2-D structure.
Conclusions:
- Functionalized GO acts as an efficient and selective enzyme positive modulator.
- Demonstrated a proof-of-concept enzyme-based bioassay system using GO.
- Highlights novel potential of functionalized GO in enzyme engineering and enzyme-based biosensing.
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