A practical teaching course in directed protein evolution using the green fluorescent protein as a model.

Area of Science:

• Biochemistry
• Molecular Biology
• Protein Engineering

Background:

• Protein engineering is crucial for understanding protein structure-function relationships.
• Green fluorescent protein (GFP) from Aequorea victoria is a vital tool in biotechnology and research.
• Random mutagenesis is a common strategy for protein variant generation.

Purpose of the Study:

• To present a practical teaching course on engineering GFP.
• To identify GFP variants with improved fluorescence using random mutagenesis.
• To correlate structural changes with functional improvements in GFP.

Main Methods:

• Random mutagenesis using error-prone polymerase chain reaction (PCR).
• Construction and screening of random mutant libraries in bacterial colonies.
• Three-dimensional structural mapping of selected GFP mutants.

Main Results:

• Identified GFP variants with significantly increased fluorescence yields.
• Demonstrated that alterations in the fluorophore's microenvironment affect fluorescence.
• Showed that changes in protein surface properties influence protein solubility.

Conclusions:

• Protein engineering via random mutagenesis can effectively enhance GFP fluorescence.
• Structural insights are key to understanding and optimizing protein function.
• This approach provides a valuable educational framework for protein engineering.