A new look at the fluorescent protein-based approach for identifying optimal coding sequence for recombinant protein...

Area of Science:

• Molecular Biology
• Biotechnology
• Genetics

Background:

• The genetic code's degeneracy allows multiple codons for one amino acid.
• Synonymous codon choice impacts protein expression, particularly in Escherichia coli.
• mRNA secondary structures at the 5'-end can hinder translation initiation.

Purpose of the Study:

• To develop an efficient method for optimizing protein expression using synonymous codon substitutions.
• To overcome limitations of in silico gene optimization.
• To enhance the expression of poorly expressed proteins in bacteria.

Main Methods:

• Creation of a partially randomized library of expression constructs with selected synonymous variants.
• Fusion of the gene of interest to a fluorescent protein reporter gene.
• Screening of variants based on reporter signal intensity to identify high-expression candidates.

Main Results:

• Demonstrated a significant increase in prokaryotic expression for three proteins: canine cystatin C, human BCL2-associated athanogene 3, and human cardiac troponin I.
• Validated the effectiveness of the screening approach for identifying optimal synonymous codon variants.
• Achieved substantial improvements in protein yields through this method.

Conclusions:

• A novel, simple, and cost-effective approach for optimizing protein expression in bacteria was developed.
• This method offers an efficient alternative to in silico optimization for poorly expressed proteins.
• The screening of randomized libraries provides a powerful tool for genetic engineering and protein production.