[Compatible-solute-supported periplasmic expression of recombinant immunotoxins and the effects of glucose thereby]

Bacteria protect themselves against high external osmolality by uptake or synthesis of a limited number of so-called compatible solutes. Under such extreme conditions, combine factors can facilitate the foreign recombinant protein expression. In our experiment, we added additional NaCl and two compatible solutes (glycine betaine and sorbitol) into the medium. The recombinant immunotoxin BDI(scFv)-PE38 was expressed mainly in soluble form and can be purified by Ni2+-NTA agarose. We also found the time when the glucose was added into the medium greatly affected the expression level of the recombinant immunotoxin. This suggested that glucose played an important role in the expression system.