Fusion of plectasin derivative NZ2114 with hydrophilic random coil polypeptide: Recombinant production in Pichia pastoris and antimicrobial activity against clinical strain MRSA.

One of the roadblocks towards the practical use of antimicrobial peptides for medical use is their relatively high cost when synthesized chemically. Effective recombinant production has only been successful in some cases, such as the previously reported production in Pichia pastoris of the antimicrobial plectasin derivative peptide NZ2114. The same production host has also been used extensively to produce so-called protein-polymers: sequences that consist of repetitions of simple amino acid motifs found in structural proteins such as collagen and elastin, and that can be designed to self-assemble in micelles, fibers and hydrogels. With the eventual goal of producing recombinant biomaterials such as antimicrobial protein polymer, we here explore the secreted production in Pichia pastoris of a fusion of NZ2114 with a hydrophilic random coil protein polymer CP4 . The intact NZ2114-CP4 fusion copolymer was produced with a yield of purified protein on the order of 1 g.L-1 supernatant. We find that purified NZ2114-CP4 has an activity against clinical strain MRSA, but very much lower than activity of chemically synthesized NZ2114. We conclude that possibly, the activity of NZ2114 is impaired by the C-terminal attachment to the protein polymer chain, but other reasons for the low activity cannot yet be excluded either. This article is protected by copyright. All rights reserved.