Isolated recombinant cDNA

US9545431B1 · kind B1 · utility

Assignee

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

Inventor

• David M. Donovan · Baltimore, US

Key dates

• Filing date: May 21, 2009
• Grant date: Jan 17, 2017
• Expiry date: May 5, 2032

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C12N9/503
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

The routine use of antibiotics to battle Streptococcal pathogens has produced a new class of superbug—multi-drug resistant streptococci resulting in a need for new antimicrobials. The LambdaSa2 prophage endolysin gene harbors an amidase-5 (endopeptidase), an amidase-4 (glycosidase) domain and two Cpl-7 cell wall-binding domains. This endolysin can digest the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae and Staphylococcus aureus. Turbidity reduction and plate lysis assays indicate that this peptidoglycan hydrolase also shows strong lytic activity toward Streptococcus pyogenes, Streptococcus dysgalactiae, Streptococcus uberis, Streptococcus equi, GES, and GGS. Deletion analysis on the His-tagged version of this gene further indicates that the N-terminal endopeptidase domain is minimally active in the absence of a Cpl-7 domain when lysing cells from without; however, with both Cpl-7 domains, it achieves a higher specific activity than the full length protein (on some strains) and shows weak activity against two Coagulase Negative Staphylococci, Staphylococcus hyicus and Staphylococcus xyloses.