Recommended Name ?N-acetylmuramoyl-L-alanine amidase
Systematic Name ?peptidoglycan amidohydrolase
Alternative Name ?endolysin LysK
acetylmuramoyl-alanine amidase
acetylmuramyl-alanine amidase
acetylmuramyl-L-alanine amidase
N-acetylmuramic acid L-alanine amidase
N-acetylmuramyl-L-alanine amidase
N-acetylmuramylalanine amidase
N-acylmuramyl-L-alanine amidase
peptidoglycan amidohydrolase
Uniprot IDQ6Y7T6
General Mode of ActionEnzymatic cleavage of peptidoglycan which results in a rapid lysis of the bacterial cell.
phiBIOTICS Family ?NAM amidase
Reaction ?1. Catalysis of the hydrolysis of the link between N-acetylmuramoyl residues and L-amino acid residues in certain bacterial cell-wall glycopeptides (R04112)
    Corresponding Pfam domain: Amidase_2
    Evidence: experimental (PubMed: 19493008)
2. Catalysis of the hydrolysis of the peptide bond between D-alanine and glycine in cell wall peptidoglycans
    EC: n/a
    Corresponding Pfam domain: CHAP
    Evidence: experimental (PubMed: 19493008)
Source Organism ?Staphylococcus phage K
Target Organism ?Staphylococcus aureus
Disease ?Infective endocarditis
Nosocomial infections
State ?Tested
Reference ?19493008

Studies found: 1

Antimicrobial Agent
Study Type
AdministrationRelevant ResultsAdverse Effects and Other IssuesReference ?
LysK in vitro
  • Set of various human and bovine strains of S. aureus including MRSA and VRSA. LysK was applied on autoclaved and live staphylococci.
  • Set of other gram-positive bacteria: Lactococcus lactis, Lactobacillus lactis, Lactobacillus rhamnosous, Lactobacillus paracasei, Listeria innocua, Bacillus cereus
Recombinant lysine LysK produced in Lactococcus lactis was examined for its ability to degrade staphylococcal cell walls.

Lactococcal lysates containing LysK was able to form lytic zone in autoclaved staphylococci (zymographic analysis).

LysK demonstrated capability to kill live pathogenic staphylococci (including MRSA and VRSA). S. aureus strain DPC5654 (3 ml) was grown to an optical density (OD) of approximately 0.1 at 600 nm, when 500 µl of the lactococcal extract containing LysK was added. 99% reduction in staphylococcal cell numbers was observed after 1 h after the addition of lysates containing LysK. A different lytic ability was observed with different staphylococcal strains.

Other gram-positive bacteria from different genera including beneficial probiotic strains were not affected by LysK.