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

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.