Keary, R,Sanz-Gaitero, M,van Raaij, MJ,O'Mahony, J,Fenton, M,McAuliffe, O,Hill, C,Ross, RP,Coffey, A

2016

January

Current Protein & Peptide Science

Characterization of a Bacteriophage-Derived Murein Peptidase for Elimination of Antibiotic-Resistant Staphylococcus aureus

Validated

()

Bacteriophage CHAP Domain Endolysin Murein/peptidoglycan hydrolase Staphylococcus aureus LYTIC ENZYME CPL-1 STREPTOCOCCUS-PNEUMONIAE PHAGE ENDOLYSIN IN-VIVO ANTIMICROBIAL ACTIVITY CRYSTAL-STRUCTURE ESCHERICHIA-COLI BACILLUS-CEREUS NASAL CARRIAGE MRSA INFECTION

17

183

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Staphylococcus aureus is a major cause of infection in humans and animals, causing a wide variety of diseases, from local inflammations to fatal sepsis. The bacterium is commonly multi-drug resistant and thus many front-line antibiotics have been rendered ineffective for treating such infections. Research on murein/peptidoglycan hydrolases, derived from bacterial viruses (bacteriophages), has demonstrated that such proteins are attractive candidates for development as novel antibacterial agents for combatting Gram-positive pathogens. Here we review the research produced to-date on the bacteriophage-derived CHAPK murein peptidase. Initially, we sequenced and annotated the genome of anti-staphylococcal bacteriophage K and cloned the gene for the bacteriophage endolysin, a murein hydrolase which plays a role in cell killing during the bacteriophage life cycle. An highly active domain of the enzyme, a cysteine, histidine-dependent amido hydrolase/peptidase (CHAPK), was cloned, over-expressed in E. coli and purified. This CHAPK enzyme was demonstrated to rapidly lyse several strains of methicillin resistant S. aureus and both disrupted and prevented the formation of a staphylococcal biofilm. The staphylolytic activity of the peptidase was demonstrated in vivo using a mouse model, without adverse effects on the animals. The crystal structure of the enzyme was elucidated, revealing a calcium ion close to the active site. Site-directed mutagenesis indicated that this calcium ion is involved in the catalytic mechanism of the enzyme. The crystal structure of this enzyme is a valuable source of information for efficient engineering of this and similar CHAP-domain-containing proteins. Overall, the data collected to date on CHAPK has demonstrated its strong potential as a novel therapeutic candidate for treatment of staphylococcal infections and has provided us with insight into the fundamental enzymatic mechanisms of CHAP domain-containing peptidoglycan hydrolases.

10.2174/1389203716666151102105515