Lactoferricin B inhibits bacterial macromolecular synthesis in and

Abstract

Most antimicrobial peptides have an amphipathic, cationic structure, and an effect on the cytoplasmic membrane of susceptible bacteria has been postulated as the main mode of action. Other mechanisms have been reported, including inhibition of cellular functions by binding to DNA, RNA and proteins, and the inhibition of DNA and/or protein synthesis. Lactoferricin B (Lfcin B), a cationic peptide derived from bovine lactoferrin, exerts slow inhibitory and bactericidal activity and does not lyse susceptible bacteria, indicating a possible intracellular target. In the present study incorporation of radioactive precursors into DNA, RNA and proteins was used to demonstrate effects of Lfcin B on macromolecular synthesis in bacteria. In Escherichia coli UC 6782, Lfcin B induces an initial increase in protein and RNA synthesis and a decrease in DNA synthesis. After 10 min, the DNA-synthesis increases while protein and RNA-synthesis decreases significantly. In Bacillus subtilis, however, all synthesis of macromolecules is inhibited for at least 20 min. After 20 min RNA-synthesis increases. The results presented here show that Lfcin B at concentrations not sufficient to kill bacterial cells inhibits incorporation of radioactive precursors into macromolecules in both Gram-positive and Gram-negative bacteria.

Consequences of N-Acylation on Structure and Membrane Binding Properties of Dermaseptin Derivative K4-S4-(1-13)

“…Although the cytoplasmic membrane of target cells (including that of bacteria) is widely believed to be the ultimate target of many AMPs, various intracellular potential targets have been proposed (26,61,62) to account for the ability of certain AMPs to spontaneously translocate across the plasma membrane of various cell types at nontoxic concentrations (63,64). Whether representing a final or intermediate step in the mechanism of action, it is nevertheless clear that the interaction of AMPs with the plasma membrane plays an important role in their biological activity.…”

Design of Host Defence Peptides for Antimicrobial and Immunity Enhancing Activities

“…Interestingly, a Yersinia pestis homologue of this protein, Pla, is known to be expressed at body temperature and is a virulence factor involved in the mobility of the bacterium from a subcutaneous wound to distal sites [100]. Furthermore, studies that looked at the susceptibility of both Gram-positive and Gram-negative bacteria in the presence of protease inhibitors suggested that a number of intracellular proteases like DegP, also contributed to the intrinsic resistance of a number of bacteria to cationic peptides [101].…”

Expression, Purification, and Antibacterial Activity of Bovine Lactoferrampin–Lactoferricin in Pichia pastoris

“…This innate immunity factor contains two antimicrobial domains: lactoferricin (LFC) 17-30, found as a pepsin digestion product [1,2], and lactoferrampin (LFA) 265-284 [3][4][5], which can also be released from bovine lactoferrin by proteolytic digestion. Related synthetic peptides from both domains show broad-spectrum bactericidal activities against a range of Gram-positive and Gram-negative bacteria [6][7][8][9]. In addition, LFC has been shown to have antifungal [10,11], antiviral [12][13][14][15], and antitumor activities [11,16].…”