Production of repetitive amino acid sequenced protein in Escherichia coli.

Abstract

Repetitive sequenced proteins and polypeptides are being highlighted as being the next new biomaterial for the future. Not only do they display outstanding mechanical properties, the proteins also exhibit biocompatibility. Spider silk has attracted much attention in the biotechnology field due to its great physical properties: strength, toughness, elasticity, as well as biocompatibility and biodegradability. However, mass production of spider silk has been imposed by the aggressive territorialism and cannibalism of spiders. Alternative ways to produce the silk has been studied including production of recombinant spider silk protein through Escherichia coli. This study shows the increased production of native- sized recombinant spider silk protein through engineering of promoters and introducing synthetic biology approach to increase the production of the silk protein. In addition, production of artificially made recombinant protein was shown as well. Tyrosine and phenylalanine were repeated within the recombinant gene and was expressed successfully in the E.coli system for the first time to our knowledge. In addition, to increase the production of the recombinant protein, charged tRNAs of both tyrosine and phenylalanine were expressed within the cell. These results show the possibility of mass production of spider silk protein as well as genetic strategies for expressing high molecular weight and repetitive sequenced proteins.