Related Experiment Video
Updated: Mar 21, 2026

Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells
Published on: April 20, 2017
Efficient recombinant expression of SFTI-1 in bacterial cells using intein-mediated protein trans-splicing
Yilong Li1, Teshome Aboye1, Leonard Breindel2
1Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, 90089-9121.
Abstract:
We report for the first time the recombinant expression of bioactive wild-type sunflower trypsin inhibitor 1 (SFTI-1) inside E. coli cells by making use of intracellular protein trans-splicing in combination with a high efficient split-intein. SFTI-1 is a small backbone-cyclized polypeptide with a single disulfide bridge and potent trypsin inhibitory activity. Recombinantly produced SFTI-1 was fully characterized by NMR and was observed to actively inhibit trypsin. The in-cell expression of SFTI-1 was very efficient reaching intracellular concentration ≈ 40 µM. This study clearly demonstrates the possibility of generating genetically encoded SFTI-based peptide libraries in live E. coli cells, and is a critical first step for developing in-cell screening and directed evolution technologies using the cyclic peptide SFTI-1 as a molecular scaffold. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 818-824, 2016.
Related Concept Videos
Tagging and Fusion Proteins
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Reporter Genes

