Effect of the selection marker on the viability and plasmid stability of two human proteins with neurotrophic action expressed in Escherichia coli.
Most developed expression systems rely on the production of fusion proteins or the change of selection marker increasing genetic stability to avoid toxicity of heterologous proteins to Escherichia coli host cells. According to this, we analyzed the effect of the selection marker on the viability and plasmid stability of vectors pYMK5 and pYMK7 that codify neurotrophic factors brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). We also analyzed the influence of two different lac promoter inducers on these parameters. We found that the addition of IPTG to culture medium produced a significant decrease of viability and plasmid stability for both expression vectors compared with values reached with lactose. There was no increase of both parameters when we changed the selection marker, so we can conclude that, in our case, a change of antibiotic does not solve the problem of low plasmid stability values.
Marí
Y M
YM
Pharmaceutical Division, Biopharmaceutical Development Division, Center for Genetic Engineering and Biotechnology, Playa 10600, Havana, Cuba.
Espinosa
A E
AE
Ubieta
R
R
Batista
O F
OF
Fernández
M L
ML
D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005819:Genetic Markers; D006801:Humans; D007763:Lac Operon; D009414:Nerve Growth Factors / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D019208:Brain-Derived Neurotrophic Factor; D005819:Genetic Markers; D009414:Nerve Growth Factors; D011994:Recombinant Proteins