Antimicrobial activity of bovine lactoferrin-derived peptides

Antimicrobial peptides, such as bovine lactoferrin (bLF), are produced by a wide variety of organisms. AMPs represent a first line defence against invading microbes and are found in large quantity in several secretory fluids [1] . They are relatively short, amphiphilic and positively charged. bLF is an 80- kDa iron-binding, multifunctional cationic glycoprotein of the transferrin family. This protein is active against a widespread range of microbiological organisms: bacteria, viruses, fungi and parasites [2,3,4]. In order to obtain novel active peptides from bLF, several approaches have been used. Two novel active peptides have been identified in our study. In agreement with the not disclosure agreement for the pending patent N°102015000044047*, we are not allowed to report the sequences in the abstract. These peptides, named respectively KFp and LKp, were synthesized using the standard solid-phase- 9-fluorenylmethoxycarbonyl (Fmoc) method. Antibacterial activity of KFp and LKp was analyzed by minimal inhibitory concentration (MIC) using the broth microdilution method outlined by the Clinical and Laboratory StandardsInstitute (CLSI) on two bacteria strains: Escherichia coli ATCC 11229 and Staphylococcus aureus ATCC 6538. Likewise, the antiviral activity was performed on HSV-1using a co-treatment assay. Moreover, their cytotoxicity activity was evaluated by the MTT assay.According to the study conducted, these novel peptides show a marked broad-spectrum antimicrobial and antiviral activity with a low toxicity. This can be a favorable prerequisite for the developing and for the use of these peptides in vivo, as additional therapeutic agents and/or as alternative to the conventional antibiotics.