cDNA Cloning of a Bovine Insulin-like growth factor-1 from Egyptian Buffalos and Expression of its Recombinant Protein in Escherichia coli

ABSTRACT Insulin-like growth factor-1 (IGF-1) is regarded as a crucial clinically significant therapeutic agent against several pathological conditions. Recently, recombinant DNA (rDNA) technology has enabled the production of many drugs of rDNA-origin including IGF-1. Securing a readily available supply of IGF-1 is invaluable to clinical research and biotechnological domains. In this work, the cloning of a full-length bovine IGF-1 cDNA and the successful expression of its cognate recombinant IGF-1 protein is reported. Single-strand cDNA was prepared from liver tissues, through the specific reverse transcription (RT) of IGF-1 mRNA. Subsequently, a PCR amplicon of ~543bp was successfully amplified. Recombinant pTARGET™ vector harboring IGF-1 insert was successfully cloned into competent E. coli JM109 cells. SDS-PAGE analysis revealed that the recombinant IGF-1 has been expressed at the expected size of 7.6kDa. The outcome provides a robust basis for transecting the recombinant pTARGETTM vector, harboring the IGF-1 cDNA insert, into mammalian cells. Optimal initial glucose concentration was found to be 10g/l with corresponding protein concentration of 6.2g/l. The proliferative biological activity crude recombinant IGF-1 protein was verified on HeLa cell lines. This is envisaged to facilitate large-scale production of recombinant IGF-1 protein, thereby enabling thorough investigation of its clinical and pharmaceutical effects.