Broad spectrum of Streptococcus lyase and use thereof

Inventors

Wei, Hongping • Yang, Hang • Wang, Jing • Yu, Junping

Assignees

Precisio Biotix Therapeutics Inc

Abstract

This invention discloses a lysin that can kill many species of Streptococci. A new lysin, ClyR, was constructed by the gene splicing method. The ClyR can effectively kill different species of Streptococci, including Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus suis, Streptococcus uberis, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus mutans, Streptococcus equi, and various Enterococci and Staphylococcus aureus. ClyR shows good stability and is not sensitive to EDTA and high concentration of NaCl. Moreover, the ClyR is active in a wide range of pH and maintains high activity in pH 5-11. Recombinant protein ClyR is well expressed in E. coli stain BL21 (DE3). High doses of ClyR showed no apparent toxicity in mice. Furthermore, administration of 0.8 mg per mouse once is able to completely protect the mouse infected with lethal doses of Group B Streptococci. The ClyR can be used alone or in combination with different forms of reagents and solutions, for the control of a variety of Streptococci and for the treatment of infections caused by these bacteria. It has a broad application prospect.

Core Innovation

The disclosed invention concerns an isolated and recombinant Streptococcus lyase ClyR, where the protein sequence is shown in SEQ.ID.NO.2. The invention is presented as a gene-spliced phage-derived lysin ClyR that includes a coding nucleic acid sequence (SEQ.ID.NO.1) and a corresponding protein sequence (SEQ.ID.NO.2).

ClyR shows broad lytic activity against multiple Streptococcus species, including Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus suis, Streptococcus uberis, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus mutans, and Streptococcus equi. The disclosed content further states activity against Enterococci and Staphylococcus aureus.

The disclosure further describes favorable stability and resistance to EDTA and high NaCl, and activity across pH 5–11. It reports soluble expression in E. coli BL21(DE3), in vivo protection in mice against lethal Group B Streptococcus, lack of cytotoxicity in Caco-2 cells, and antimicrobial elimination of Streptococcus in milk.

Claims Coverage

The partial content provides one independent claim and multiple dependent claims. Across the set, the inventive features focus on the sequence-defined recombinant ClyR, gene/vector embodiments, expression and purification related refinements, and use as a killing agent and medicament/formulation for specific bacterial targets and contexts.

The independent claim anchors protection on a sequence-defined recombinant ClyR protein (SEQ.ID.NO.2). Dependent claim coverage, as provided in the partial content, extends from a SEQ.ID.NO.1 encoding gene in a vector, through a soluble expression and purification workflow, to killing methods targeting Streptococcus, Enterococcus, and Staphylococcus aureus, and to medicament and composition uses such as bovine mastitis and an antibiotic composition containing ClyR.

Stated Advantages

Documented Applications