Plasmid-based CTX phage replication system and vibrio cholerae strain that can be infected by CTX phage and can be used for cholera toxin production

Patent metadata

Field	Value
Publication number	US-11136358-B2
Application number	US-201916442164-A
Country	US
Kind code	B2
Filing date	Jun 14, 2019
Priority date	Dec 16, 2016
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

The present invention relates to a plasmid-based CTX phage replication system and Vibrio cholerae strain that can be infected by CTX phage and can be used for cholera toxin production. More particularly, the present invention provides a Vibrio cholera variant strain, which expresses a toxT protein in which tyrosine at position 139 is substituted by phenylalanine through the point mutation of a toxT gene using a plasmid-based CTX phage replication system, and is used as a receptor strain which can improve CTX phage infection efficiency and allows a plurality of CTX prophages to simultaneously infect the strain and to be inserted into the chromosome thereof, which the consequent provision of the effect of increasing the production yield of a cholera toxin.

First claim

What is claimed is:

1. A Vibrio cholerae variant strain, comprising:
expressing a toxT protein having the amino acid sequence of SEQ ID NO: 7 in which Tyr at amino acid 139 of SEQ ID NO: 7 is substituted with Phe through the point mutation of a toxT gene.

2. The Vibrio cholerae variant strain according to claim 1 , wherein the Vibrio cholerae variant strain is used as a recipient strain for CTX phage infection.

3. The Vibrio cholerae variant strain according to claim 1 , wherein the Vibrio cholerae variant strain uses a classical biotype, E1 Tor biotype, atypical E1 Tor biotype or O139 serotype Vibrio cholerae strain as a parental strain to prepare the Vibrio cholerae variant strain.

4. The Vibrio cholerae variant strain according to claim 1 , wherein the Vibrio cholerae variant strain is a toxigenic Vibrio cholerae variant strain comprising one or more CTX prophages selected from the group consisting of CTX-1, CTX-cla, CTX-2, CTX-env, and CTX-O139 having a cholera toxin gene.

5. The Vibrio cholerae variant strain according to claim 1 , wherein the Vibrio cholerae variant strain is a toxigenic Vibrio cholerae variant strain comprising a cholera toxin gene inserted on the chromosome of the strain.

Assignees

• Iucf Hyu Erica Campus

Inventors

• Kim Dong Wook
• Kim Eun Jin
• Yu Hyun Jin

Classifications

• C12N7/00

  Viruses; Bacteriophages; Compositions thereof; Preparation or purification thereof (preparing medicinal viral antigen or antibody compositions, e.g. virus vaccines, A61K39/00) · CPC title

• C12R2001/63

  Vibrio · CPC title

• C07K14/28 Primary

  from Vibrionaceae (F) · CPC title

• C12N2795/14143

  viral genome or elements thereof as genetic vector · CPC title

• C12N2795/00042

  virus or viral particle as vehicle, e.g. encapsulating small organic molecule · CPC title