Degradation of human antimicrobial peptide LL-37 by Staphylococcus aureus-derived proteinases.
Cathelicidin LL-37 is one of the few human bactericidal peptides with potent antistaphylococcal activity. In this study we examined the susceptibility of LL-37 to proteolytic degradation by two major proteinases produced by Staphylococcus aureus, a metalloproteinase (aureolysin) and a glutamylendopeptidase (V8 protease). We found that aureolysin cleaved and inactivated LL-37 in a time- and concentration-dependent manner. Analysis of the generated fragments by mass spectroscopy revealed that the initial cleavage of LL-37 by aureolysin occurred between the Arg19-Ile20, Arg23-Ile24, and Leu31-Val32 peptide bonds, instantly annihilating the antibacterial activity of LL-37. In contrast, the V8 proteinase hydrolyzed efficiently only the Glu16-Phe17 peptide bond, rendering the C-terminal fragment refractory to further degradation. This fragment (termed LL-17-37) displayed antibacterial activity against S. aureus at a molar level similar to that of the full-length LL-37 peptide, indicating that the antibacterial activity of LL-37 resides in the C-terminal region. In keeping with LL-37 degradation by aureolysin, S. aureus strains that produce significant amounts of this metalloprotease were found to be less susceptible to LL-17-37 than strains expressing no aureolysin activity. Taken together, these data suggest that aureolysin production by S. aureus contributes to the resistance of this pathogen to the innate immune system of humans mediated by LL-37.
Sieprawska-Lupa
Magdalena
M
Department of Microbiology, Faculty of Biotechnology, Jagiellonian University, Kraków, Poland.
Mydel
Piotr
P
Krawczyk
Katarzyna
K
Wójcik
Kinga
K
Puklo
Magdalena
M
Lupa
Boguslaw
B
Suder
Piotr
P
Silberring
Jerzy
J
Reed
Matthew
M
Pohl
Jan
J
Shafer
William
W
McAleese
Fionnuala
F
Foster
Timothy
T
Travis
Jim
J
Potempa
Jan
J
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D001426:Bacterial Proteins; D015153:Blotting, Western; D003114:Colony-Forming Units Assay; D006801:Humans; D008666:Metalloendopeptidases / Q000302:isolation & purification / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics; D054804:Cathelicidins
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D008666:Metalloendopeptidases; C115504:aureolysin; D054804:Cathelicidins