title: Recombinant expression of Bacillus anthracis lethal toxin components of Indian isolate in Escherichia coli and determination of its acute toxicity level in mouse model.
abstract: Bacillus anthracis lethal toxin (LeTx) is the principle factor responsible for toxaemia and anthrax related death. Lethal toxin consist of two proteins viz protective antigen (PA) and lethal factor which combines in a typical fashion similar to other toxins belonging to A-B toxin super family. The amount of LeTx required to kill a particular organism generally differs among strains owing to their geographical distributions and genetic variation. In the present study, we have cloned PA and LF genes from B. anthracis clinical isolate of Indian origin and expressed them in soluble form employing Escherichia coli expression system. Both the proteins were purified to near homogeneity level using Immobilized metal ion affinity chromatography (IMAC). Further we have used equal ratio of both the proteins to form LeTx and determined its acute toxicity level in Balb/c mice by graphical method of Miller and Tainter. The LD50 value of LeTx by intravenous (i.v) route was found to be 0.97 ± 0.634 mg kg(-1) Balb/c mice. This study highlights the expression of recombinant LeTx from E. coli and assessing its acute toxicity level in experimental mouse model.
authors.affiliation: Division of Microbiology, Defence Research and Development Establishment, Gwalior, Madhya Pradesh 474002, India. Electronic address: nagendranavada06@gmail.com.
authors.forename: Suryanarayana
authors.initials: S
authors.lastname: Nagendra
authors.affiliation: Division of Microbiology, Defence Research and Development Establishment, Gwalior, Madhya Pradesh 474002, India. Electronic address: vanlalh@gmail.com.
authors.lastname: Vanlalhmuaka
authors.affiliation: Division of Microbiology, Defence Research and Development Establishment, Gwalior, Madhya Pradesh 474002, India. Electronic address: sarika191208@gmail.com.
authors.forename: Sarika
authors.initials: S
authors.lastname: Verma
authors.affiliation: Division of Microbiology, Defence Research and Development Establishment, Gwalior, Madhya Pradesh 474002, India. Electronic address: urmil_tuteja@yahoo.co.in.
authors.forename: Urmil
authors.initials: U
authors.lastname: Tuteja
authors.affiliation: Division of Microbiology, Defence Research and Development Establishment, Gwalior, Madhya Pradesh 474002, India. Electronic address: kt_drde@rediffmail.com.
authors.forename: Kulanthaivel
authors.initials: K
authors.lastname: Thavachelvam
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000633:toxicity*; D001408:Bacillus anthracis; D001427:Bacterial Toxins / Q000235:genetics / Q000633:toxicity*; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D005843:Geography; D007194:India; D007928:Lethal Dose 50; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000378:metabolism; D023382:Toxicity Tests, Acute
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D011994:Recombinant Proteins; C030325:anthrax toxin
keywords: Bacillus anthracis; Lethal toxin; Log dose; Miller and Tainter method; Probit analysis; Protective antigen