Abstract: Provided herein are methods of improving solubilization, extraction, and isolation of recombinant spider silk proteins with a salt and alcohol buffer. Provided herein are methods of solubilizing a recombinant spider silk protein from a host cell, comprising: providing a cell culture comprising a host cell, wherein the host cell expresses a recombinant spider silk protein; collecting an insoluble portion derived from the cell culture, wherein the insoluble portion comprises the recombinant spider silk protein; adding the insoluble portion of the host cell to a solution comprising a salt and an alcohol, thereby solubilizing the recombinant spider silk protein in the solution.

Abstract: The present disclosure relates to methods of producing and purifying synthetic block copolymer proteins, expression constructs for their secretion, recombinant microorganisms for their production, and synthetic fibers comprising these proteins that recapitulate many properties of natural silk.