1. Halocyntin and papillosin, two new antimicrobial peptides isolated from hemocytes of the solitary tunicate, Halocynthia papillosa
Richard Galinier, Emmanuel Roger, Pierre-Eric Sautiere, Andre Aumelas, Bernard Banaigs, Guillaume Mitta J Pept Sci. 2009 Jan;15(1):48-55. doi: 10.1002/psc.1101.
We report here the screening of five marine invertebrate species from two taxa (tunicates and echinoderms) for the presence of cationic antimicrobial peptides (AMP) in defence cells (hemocytes). Antimicrobial activities were detected only in the two tunicates Microcosmus sabatieri and Halocynthia papillosa. In addition, we report the isolation and characterization of two novel peptides from H. papillosa hemocytes. These molecules display antibacterial activity against Gram-positive and Gram-negative bacteria. Complete peptide characterization was obtained by a combination of Edman degradation and mass spectrometry. The mature molecules, named halocyntin and papillosin, comprise 26 and 34 amino acid residues, respectively. Their primary structure display no significant similarities with previously described AMP.
2. Potent antimicrobial peptides with selectivity for Bacillus anthracis over human erythrocytes
Raymond M Dawson, Marc A Fox, Helen S Atkins, Chun-Qiang Liu Int J Antimicrob Agents. 2011 Sep;38(3):237-42. doi: 10.1016/j.ijantimicag.2011.05.006. Epub 2011 Jul 8.
In this study, 39 antimicrobial peptides, most with documented low haemolytic activity and potent efficacy against Gram-negative and Gram-positive bacteria, were evaluated for their haemolytic activity against human red blood cells as well as their antimicrobial activity against Escherichia coli, Burkholderia thailandensis, Bacillus globigii and Bacillus anthracis. The majority of the peptides had a minimum inhibitory concentration (MIC) of 30 and could be considered as candidates for further development for potential medical countermeasures against anthrax. Although B. globigii has often been used as a non-pathogenic simulant for B. anthracis, in this study it was found that the sensitivity of B. globigii to peptides was not a reliable predictor of the sensitivity of B. anthracis to the same peptides.
3. Recent patents on antimicrobial peptides
Firoz K Pathan, Deepa A Venkata, Siva K Panguluri Recent Pat DNA Gene Seq. 2010 Jan;4(1):10-6. doi: 10.2174/187221510790410831.
Research on antimicrobial peptides has gained pace to exploit their potential and ability to replace conventional antibiotics. Antimicrobial peptides are important members of the host defense system, as they have a broad ability to kill microbes. Antimicrobial peptides and proteins form an important means of host defense in eukaryotes. Large antimicrobial proteins (>100 a.a.), are often lytic, nutrient-binding proteins or specifically target the microbial macromolecules. Small antimicrobial peptides act by disrupting the structure or function of microbial cell membranes. A multitude of antimicrobial peptides has been found in the epithelial layers, phagocytes, and body fluids of multicellular animals including humans. Aside from their role as endogenous antibiotics, antimicrobial peptides have functions in inflammation, wound repair, and regulation of the adaptive immune system. In this review, we discuss recent patents relating to antimicrobial peptides. These patents are related to the method of identifying peptides that have antimicrobial activity, including the papillosin antimicrobial peptide and its encoding gene, the antimicrobial peptide isolated from Halocynthia aurantium, retrocyclins, and the use of cathelicidin LL-37 and its derivatives for wound healing. These patents provide valuable information that could be useful in the identification of antimicrobial peptides and the exploitation of their therapeutic potential.
