title: Acid extraction and purification of recombinant spider silk proteins.
abstract: A procedure has been developed for the isolation of recombinant spider silk proteins based upon their unique stability and solubilization characteristics. Three recombinant silk proteins, (SpI)7, NcDS, and [(SpI)4/(SpII)1]4, were purified by extraction with organic acids followed by affinity or ion exchange chromatography resulting in 90-95% pure silk solutions. The protein yield of NcDS (15 mg/L culture) and (SpI)7 (35 mg/L) increased 4- and 5-fold, respectively, from previously reported values presumably due to a more complete solubilization of the expressed recombinant protein. [(SpI)4/(SpII)1]4, a hybrid protein based on the repeat sequences of spidroin I and spidroin II, had a yield of 12.4 mg/L. This method is an effective, reproducible technique that has broad applicability for a variety of silk proteins as well as other acid stable biopolymers.
authors.affiliation: U.S. Army RDECOM Natick Soldier Center, Kansas St., Massachusetts 01760-5020, USA. charlene.mello@us.army.mil
authors.forename: Charlene M
authors.initials: CM
authors.lastname: Mello
authors.forename: Jason W
authors.initials: JW
authors.lastname: Soares
authors.forename: Steven
authors.initials: S
authors.lastname: Arcidiacono
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Butler
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange / Q000379:methods; D005349:Fibroins / Q000096:biosynthesis / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification*
chemical_list: D011994:Recombinant Proteins; D005349:Fibroins