Large-scale production of soluble recombinant amyloid-β peptide 1-42 using cold-inducible expression system

Amyloid-beta peptide 1-42 (A beta(1-42)), the predominant form in senile plaques, plays important roles in the pathogenesis of Alzheimer's disease. Because A beta(1-42) has aggregation-prone nature, it has been difficult to produce in a soluble state in bacterial expression systems. In this study, we modified our expression system to increase the soluble fraction of A beta(1-42) in Escherichia coli (E. coli) cells. The expression level and solubility of recombinant A beta(1-42) induced at the low temperature (16 degrees C) is highly increased compared to that induced at 37 degrees C. To optimize expression temperature, the coding region of A beta(1-42) was constructed in a pCold vector, pCold-TF, which has a hexahistidine-tagged trigger factor (TF). Recombinant A beta(1-42) was expressed primarily as a soluble protein using pCold vector system and purified with a nickel-chelating resin. When the toxic effect of recombinant A beta(1-42) examined on human neuroblastoma SH-SY5Y cells, the purified A beta(1-42) induced cell toxicity on SH-SY5Y cells. In conclusion, the system developed in this study will provide a useful method for the production of aggregation prone-peptide such as A beta(1-42). (C) 2012 Elsevier Inc. All rights reserved.