Study on the Optimized Expression of Pseudomonas Aeruginosa Truncated Exotoxin A (PE38KDEL) in Escherichia Coli

Hina Qaiser*1, Adeen Farooq2, and Saima Iftikhar3

Abstract

The present study focused on the optimized expression of Pseudomonas aeruginosa truncated Exotoxin A (PE38KDEL) gene. This protein is considered as a
potent toxin and is largely being used in the construction of immunotoxins for targeted cancer therapy. Escherichia coli BL21 DE3 Codon Plus was used as the expression host and the protein was expressed under the control of T7 promoter system. The effects of inducer type (IPTG and lactose), inducer concentration (IPTG: 0.2, 0.5 and 1 mM/lactose: 2.0, 5.0, 10, 15 and 20 mM) and incubation period (2, 4, 6, 8 and 10 hrs) were evaluated for the expressed protein. The maximum protein production was observed when IPTG at a concentration of 0.5 mM was used as an inducer however, lactose also showed substantial protein expression at 20 mM concentration. The most suitable incubation period for optimum protein expression was 6 hrs post induction.