Expression of metallocarboxypeptidase inhibitors in Escherichia coli: effect of cysteine content and protein size in the secretory production of disulfide-bridged proteins.

Metallocarboxypeptidase inhibitors are proteins with possible applications in biomedicine given their properties as anticoagulant and antitumoral factors. They are small, eukaryotic polypeptides comprising several disulfide bridges, which makes them hard to express in inexpensive bacterial hosts. In this work, three of them were produced in high-cell-density cultures of Escherichia coli: PCI (39 residues and three bridges), LCI (66 residues and four bridges) and TCI (75 residues and six bridges).

Enhancing the secretory yields of leech carboxypeptidase inhibitor in Escherichia coli: influence of trigger factor and signal recognition particle.

The signal recognition particle (SRP) dependent secretion pathway is as an attractive alternative to Sec-dependent export for the production of disulfide-bonded and/or fast-folding recombinant proteins in the Escherichia coli periplasm. SRP, which shares a ribosomal attachment site with the molecular chaperone trigger factor (TF), recognizes highly hydrophobic signal sequence as they emerge from the ribosome and delivers ribosome nascent chain complexes to FtsY for subsequent cotranslational translocation of target proteins across the SecYEG pore. However, like in the case of Sec-dependent export, secretory yields can be limited by the accumulation of precursor proteins in the cytoplasm.

Engineering an efficient secretion of leech carboxypeptidase inhibitor in Escherichia coli.

Background: Despite advances in expression technologies, the efficient production of heterologous secreted proteins in Escherichia coli remains a challenge. One frequent limitation relies on their inability to be exported to the E. coli periplasm.