Costa, André3; Machado, Raul7; Ribeiro, Artur3; Collins, Tony3; Thiagarajan, Viruthachalam5; Neves Petersen, Maria Teresa1; Rodriguez-Cabello, Jose Carlos8; Gomes, Andreia C.3; Casal, Margarida5
1 The Faculty of Medicine, Aalborg University, VBN2 Department of Clinical Medicine, The Faculty of Medicine, Aalborg University, VBN3 unknown4 University of Minho5 International Iberian Nanotechnology Laboratory, Braga6 National University of Ireland, Galway7 University of Minho8 National University of Ireland, Galway
In the present work we explored the ABP-CM4 peptide properties from Bombyx mori for the creation of biopolymers with broad antimicrobial activity. An antimicrobial recombinant protein-based polymer (rPBP) was designed by cloning the DNA sequence coding for ABP-CM4 in frame with the N-terminus of the elastin-like recombinamer consisting of 200 repetitions of the pentamer VPAVG, here named A200. The new rPBP, named CM4-A200, was purified via a simplified nonchromatographic method, making use of the thermoresponsive behavior of the A200 polymer. ABP-CM4 peptide was also purified through the incorporation of a formic acid cleavage site between the peptide and the A200 sequence. In soluble state the antimicrobial activity of both CM4-A200 polymer and ABP-CM4 peptide was poorly effective. However, when the CM4-A200 polymer was processed into free-standing films high antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and filamentous fungi was observed. The antimicrobial activity of CM4-A200 was dependent on the physical contact of cells with the film surface. Furthermore, CM4-A200 films did not reveal a cytotoxic effect against both normal human skin fibroblasts and human keratinocytes. Finally, we have developed an optimized ex vivo assay with pig skin demonstrating the antimicrobial properties of the CM4-A200 cast films for skin applications.
Biomacromolecules, 2015, Vol 16, Issue 2, p. 625-635