Recombinant production of rhesus θ-defensin-1 (RTD-1) using a bacterial expression system.
Defensins are antimicrobial peptides that are important in the innate immune defense of mammals. In contrast to mammalian α- and β-defensins, rhesus θ-defensin-1 (RTD-1) comprises only 18 amino acids stabilized by three disulfide bonds and an unusual backbone cyclic topology. In this work we report for the first time the recombinant expression of the fully folded θ-defensin RTD-1 using a bacterial expression system. This was accomplished using an intramolecular native chemical ligation in combination with a modified protein-splicing unit. RTD-1 was produced either in vitro or in vivo. In-cell production of RTD-1 was estimated to reach an intracellular concentration of ~4 μM. Recombinant RTD-1 was shown to be correctly folded as characterized by heteronuclear-NMR and by its ability to specifically inhibit lethal factor protease. The recombinant production of folded θ-defensins opens the possibility to produce peptide libraries based on this peptide scaffold that could be used to develop in-cell screening and directed evolution technologies.
Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033, USA.
Andrew
A
Gould
Yilong
Y
Li
Subhabrata
S
Majumder
Angie E
AE
Garcia
Patrick
P
Carlsson
Alexander
A
Shekhtman
Julio A
JA
Camarero
D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D003001:Cloning, Molecular; D023082:Defensins / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008253:Macaca mulatta; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics
D000596:Amino Acids; D023082:Defensins; D010456:Peptides, Cyclic; D011994:Recombinant Proteins