Endolysin, a peptidoglycan hydrolase derived from bacteriophage,
has been suggested as an alternative antimicrobial
agent. Many endolysins on staphylococcal phages have been
identified and applied extensively against Staphylococcus spp.
Among them, LysK-like endolysin, a well-studied staphylococcal
endolysin, accounts for most of the identified endolysins.
However, relatively little interest has been paid to LysKunlike
endolysin and a few of them has been characterized.
An endolysin LysSAP33 encoded on bacteriophage SAP33
shared low homology with LysK-like endolysin in sequence
by 41% and domain composition (CHAP-unknown CBD).
A green fluorescence assay using a fusion protein for Lys-
SAP33_CBD indicated that the CBD domain (157-251 aa)
was bound to the peptidoglycan of S. aureus. The deletion of
LysSAP33_CBD at the C-terminal region resulted in a significant
decrease in lytic activity and efficacy. Compared to
LysK-like endolysin, LysSAP33 retained its lytic activity in a
broader range of temperature, pH, and NaCl concentrations.
In addition, it showed a higher activity against biofilms than
LysK-like endolysin. This study could be a helpful tool to develop
our understanding of staphylococcal endolysins not
belonging to LysK-like endolysins and a potential biocontrol
agent against biofilms.