Large-scale production in Escherichia coli TG1 and purification of llama single domain antibody ToxA5.1 against Clostridium difficile toxin A

Drug resistant strains of Clostridium difficile are a major health concern with over 3 million cases costing over 1 billion ;Combining the HCDC strategy with a temperature shift and yeast extract addition at the time of induction, ToxA5.1 concentration of 127 mg/L was obtained. Synergistic and selective cell lysis using Triton X-100 and temperature was achieved where 95% of the available ToxA5.1 was recovered and still functional while ToxA5.1 fraction in the resulting lysate increased to 27% in the cell lysate. Single-step purification was achieved using the synthesized NNP which proved to be highly selective and could be used up to five times. Diameter of the NNP synthesized was controlled by using various concentration of ranging from 131 +/- 80 nm to 47 +/- 20 nm. Using experimental data from binding isotherm, the ToxA5.1-NNP system was modeled.