Antimicrobial host defense peptides are produced by all complex organisms as well as some microbes and have diverse and complex antimicrobial activities. Collectively these peptides demonstrate a broad range of antiviral and antibacterial activities and modes of action, and it is important to distinguish between direct microbicidal and indirect activities against such pathogens. The structural ...

One of the characteristics of the host defense of insects is the rapid synthesis of a variety of potent antibacterial and antifungal peptides. To date, seven types of inducible antimicrobial peptides (AMPs) have been characterized in Drosophila. The importance of these peptides in host defense is supported by the observation that flies deficient for the Toll or Immune deficiency (Imd) pathway, ...

The antibacterial activity of many small, positively charged peptides and proteins is based on pore formation in lipid bilayers. It is here proposed to arise from an electroporation effect. This hypothesis is supported by calculations of the electrostatic potential of NK-lysin associated to a membrane. For a significant area of the protein-membrane interface, the electrostatic potential is foun...

Histidine-rich glycoprotein (HRGP), an abundant heparin-binding protein found in plasma and thrombocytes, exerts antibacterial effects against Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Fluorescence studies and electron microscopy to assess membrane permeation showed that HRGP induces lysis o...

The rampant spread of antibiotic resistant bacteria has spurred interest in alternative strategies for developing next-generation antibacterial therapies. As such, there has been growing interest in cationic antimicrobial peptides (CAMPs) and their therapeutic applications. Modification of CAMPs via conjugation to auxiliary compounds, including small molecule drugs, is a new approach to develop...

Cationic antibacterial peptides (ABPs) are secreted in the airways and function in the first line of defence against infectious agents. They attack multiple molecular targets to cooperatively penetrate and disrupt microbial surfaces and membrane barriers. Antibacterial properties of ABPs, including cathelicidin LL-37, are reduced in cystic fibrosis (CF) airways as a result of direct interaction...

A novel antimicrobial short peptide was purified from earthworm (Eisenia foetida) by a five-step protocol including ammonium sulfate precipitation, ultrafiltration, DE-52 ion exchange chromatography, Sephadex G-10 column chromatography, and C-18 reversed-phase HPLC techniques. The purified peptide was applied to the MALDI-TOP MS to determine the molecular mass and was also subjected to TOF MS-M...

Alpha-melanocyte stimulating hormone (alpha-MSH) is an endogenous anti-inflammatory peptide reported to possess antimicrobial properties, however their role as antibacterial peptides is yet to be established. In the present study, we examined in vitro antibacterial activity of alpha-MSH against S. aureus strain ISP479C and several methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) S....

V13K, a 26-residue peptide, has been shown to have strong antimicrobial activity, negligible hemolytic activity, and significant anticancer activity. In the present work, V13K was used as the framework to investigate the influence of helicity, as influenced by d-amino acid substitutions in the center of the peptide polar and non-polar faces of the amphipathic helix, on biological activity. The ...

We report on a procedure for the preparation, printing and curing of antibacterial poly(N-isopropylacrylamide) nanocellulose-reinforced hydrogels. These composites present highly anisotropic microstructure which allows to control modulate resulting mechanical properties. The incorporation such nanoparticles enables us modify both strength humidity-dependent swelling direction printed parts, off...