Zahra Hajihassan - Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Seyed Kazem Hosseini - Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Alireza Zomorodipour - Molecular Biotechnology Department, National institute of Genetic Engineering and Biotechnology, Tehran, Iran

Human activin A is a member of the transforming growth factor-β superfamily consists of two similar beta subunits.Activin A is expressed by different cells and displays numerous biological activities such as control of neuronal cellproliferation and differentiation, promotion of neuronal survival in the body. Therefore, recombinant production ofactivin A is beneficial because it can be used to treat many neurodegenerative diseases such as Alzheimer s andParkinson diseases. In this study E. coli as a cheap and fast-growing host was selected to produce recombinant humanactivin A. As cytoplasmic expression of human activin A with complex structure and disulfide bonds producesinclusion bodies, so periplasmic expression of it can be beneficial. Therefore, we used modified Iranian B.licheniformis α-amylase signal peptide as a new signal peptide in order to translocate the recombinant activin Athrough the inner membrane. In this study human pro-activin A cDNA and signal sequence were cloned in pET21bvector and resulting vector transformed into the two strains of E. coli BL21. SDS-PAGE and western blot techniqueswere used to confirm recombinant activin A expression. Finally, our results indicated that the signal peptide used inthis study was effective for secretion of activin A into the periplasmic space of E. coli.

Activin A, modified α-amylase signal peptide, periplasmic expression