Antibacterial effects of lactoferricin B.
The antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin. We have examined the inhibitory efficacy of lactoferricin of bovine origin (Lf-cin B) on Escherichia coli, Proteus mirabilis and Staphylococcus aureus with or without a cell wall. We found that spheroplasts and protoplasts had a lower MIC than their counterparts with a cell wall. We also compared the efficacies of Lf-cin B (17-31) made of all L-amino acids and all D-amino acids. The peptide made of all D-amino acids was more active than the corresponding L-enantiomer. Furthermore, we examined the influence of Lf-cin B on the motility of E. coli and the influence of temperature on the susceptibility of bacteria exposed to Lf-cin B. Bacteria exposed to sub-MIC of Lf-cin B lost their motility. Bacteria exposed to Lf-cin B at 20 degrees C were more sensitive to Lf-cin B than when exposed at 37 degrees C. These findings indicate that the cell envelope is a limiting step for Lf-cin B to exert its antibiotic effect. We cannot rule out a receptor-mediated first step for Lf-cin B (17-31).
Vorland
L H
LH
Department of Medical Microbiology, University Hospital, Tromsø, Norway.
Ulvatne
H
H
Andersen
J
J
Haukland
H H
HH
Rekdal
O
O
Svendsen
J S
JS
Gutteberg
T J
TJ
D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D002417:Cattle; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D007781:Lactoferrin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010455:Peptides; D011513:Proteus mirabilis / Q000187:drug effects* / Q000502:physiology; D011523:Protoplasts / Q000187:drug effects; D013104:Spheroplasts / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D013237:Stereoisomerism; D013696:Temperature
D000900:Anti-Bacterial Agents; D010455:Peptides; C082171:lactoferricin B; D007781:Lactoferrin