A single nucleotide mutation drastically increases the expression of tumor-homing NGR-TNF α in the E. coli M15-pQE30 system by improving gene transcription.

A single nucleotide mutation drastically increases the expression of tumor-homing NGR-TNFα in the E. coli M15-pQE30 system by improving gene transcription. Appl Microbiol Biotechnol. 2021 Feb 02;: Authors: Chen J, Yang H, Feng Y, Shi Q, Li Z, Tao Z, Fan J, Jin Y, Li S, Cheng J, Lu X Abstract Due to their potent immune stimulation, tumor necrosis factor alpha (TNFα) variants with tumor-homing activity are attractive as novel antitumor drugs. The promising antitumor effect of NGR-TNFα in clinical trials triggered extensive interest in developing novel tumor-homing TNFα variants in recent years. Owing to its promising antitumor effect, NGR-TNFα is usually used as a control for newly developed tumor-homing TNFα variants. In our previous works, we produced a pericyte-targeting Z-TNFα at high levels using the Escherichia coli (E. coli) M15-pQE30 system. To further compare Z-TNFα and NGR-TNFα, we attempted to express NGR-TNFα using the same system. Surprisingly, native NGR-TNFα was expressed at a low (~ 0.2 mg/L) level in E. coli M15 containing the pQE30 plasmid. However, a single nucleotide mutation of C to G, resulting in a substitution of leucine (L) with valine (V) at the start of TNFα, increased the expression of NGR-TNFα by ~ 100 times through improving transcription. In addition, the amino acid substitution showed a little impact on the receptor binding, in vitro cytotoxicity, and in vivo antitumor effect of NGR-TNFα. A...
Source: Applied Microbiology and Biotechnology - Category: Microbiology Authors: Tags: Appl Microbiol Biotechnol Source Type: research