Cloning, expression, and characterization of a peptidoglycan hydrolase from the Burkholderia pseudomallei phage ST79

Journal Article · Thu Sep 15 00:00:00 EDT 2016 · AMB Express

DOI:https://doi.org/10.1186/s13568-016-0251-7· OSTI ID:1627035

Khakhum, Nittaya ^[1]; Yordpratum, Umaporn ^[2]; Boonmee, Atcha ^[3]; Tattawasart, Unchalee ^[2]; Rodrigues, Jorge L. M. ^[4]; Sermswan, Rasana W. ^[1]

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1. Khon Kaen Univ. (Thailand). Faculty of Medicine. Dept. of Biochemistry and Melioidosis Research Center
2. Khon Kaen Univ. (Thailand). Faculty of Medicine. Dept. of Microbiology and Melioidosis Research Center
3. Khon Kaen Univ. (Thailand). Faculty of Medicine. Dept. of Microbiology
4. Univ. of California, Davis, CA (United States). Dept. of Land, Air and Water Resources; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Genomics and Systems Biology Division

The lytic phage ST79 of Burkholderia pseudomallei can lyse a broad range of its host including antibiotic resistant isolates from within using a set of proteins, holin, lysB, lysC and endolysin, a peptidoglycan (PG) hydrolase enzyme. The phage ST79 endolysin gene identified as peptidase M15A was cloned, expressed and purified to evaluate its potential to lyse pathogenic bacteria. The molecular size of the purified enzyme is approximately 18 kDa and the in silico study cited here indicated the presence of a zinc-binding domain predicted to be a member of the subfamily A of a metallopeptidase. Its activity, however, was reduced by the presence of Zn2+. When Escherichia coli PG was used as a substrate and subjected to digestion for 5 min with 3 μg/ml of enzyme, the peptidase M15A showed 2 times higher in lysis efficiency when compared to the commercial lysozyme. The enzyme works in a broad alkaligenic pH range of 7.5–9.0 and temperatures from 25 to 42 °C. The enzyme was able to lyse 18 Gram-negative bacteria in which the outer membrane was permeabilized by chloroform treatment. Interestingly, it also lysed Enterococcus sp., but not other Gram-positive bacteria. In general, endolysin cannot lyse Gram-negative bacteria from outside, however, the cationic amphipathic C-terminal in some endolysins showed permeability to Gram-negative outer membranes. Genetically engineered ST79 peptidase M15A that showed a broad spectrum against Gram-negative bacterial PG or, in combination with an antibiotic the same way as combined drug methodology, could facilitate an effective treatment of severe or antibiotic resistant cases.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1627035
• Journal Information: AMB Express, Vol. 6, Issue 1; ISSN 2191-0855
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
Biotechnology & Applied Microbiology
Endolysins
Enzyme
Gene expression
Peptidoglycan