Phage twort endolysin CHAP domain is lytic for Staphylococcus aureus

US9567575B2 · kind B2 · utility

Assignee

• The United States of America, as represented by the Secretary of Agriculture · US

Inventors

• David M. Donovan · Baltimore, US
• Igor V. Abaev · Наркевичі, UA

Key dates

• Filing date: Sep 29, 2014
• Grant date: Feb 14, 2017
• Expiry date: Apr 2, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C12Y305/01028
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

Increases in antibiotic resistant strains of Staphylococcus aureus have elicited efforts to develop novel antimicrobials. One potential treatment includes lytic enzymes produced by staphylococcal bacteriophage during the lytic cycle. The phage Twort endolysin (PlyTW) harbors three domains, a CHAP endopeptidase, an amidase-2 domain, and a SH3b-5 cell wall binding domain. The CHAP domain alone is necessary and sufficient for lysis of live S. aureus; the amidase-2 domain alone is insufficient. Loss of the SH3b cell wall binding domain results in a 10 fold reduction of enzymatic activity in turbidity reduction and plate lysis assays compared to the full length protein. Deletion of the amidase-2 domain resulted in a protein (PlyTW Δ172-373) with lytic activity that exceeded the activity of the full length construct in both assays. Addition of Ca2+ enhanced activity in turbidity reduction assays. Chelation by the addition of EDTA or zinc inhibited the activity of all PlyTW constructs.