Difference between revisions of "Part:BBa K942004:Experience"

Latest revision as of 22:52, 30 September 2012

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Applications of BBa_K942004

Our shuttle sequence can be quite useful to other iGEM teams and anyone with the objective of producing or comparing the expression of proteins in two different expression systems. Coupled with an codon optimization for Pichia pastoris and a strain capable of reading rare codons like Rosetta Gami DE3 pLysS, Bl21 star (DE3), the outcome can be a simultaneous expression in both organisms coming from one single genetic sequence.

User Reviews

UNIQ8b9bc03b25666d21-partinfo-00000000-QINU UNIQ8b9bc03b25666d21-partinfo-00000001-QINU

This construct was used for the expression of Der f 2 in Pichia pastoris. Also, thanks to its B.P.S. (bacterial promoter sequence) it is intended to be expressed in Escherichia coli.

We achieved expression of the protein in P. pastoris cultures grown in 0.5% methanol and enough aeration. Because this part uses a secretion signal for yeasts, the protein was mainly localized in the growth medium. After being harvested, the cultures were centrifuged (5000g , 4º C, 5 min), and the supernatant was collected and purified using Vivapure Metal Chelate Maxi spin columns (Sartorius Stedim Biotech). Futhermore, the samples were concentrated with 3 kDa ultracentrifuge filters, obtaining a final concentration of 0.37 ug/uL in 500uL.Finally, Der f 2 was detected in a SDS-PAGE gel (Tris-Tricine 16%, 90 V, 2.5 h run-time) with silver staining.

We are currently trying different conditions to achieve the expression in BL21 Star (DE3), JM109 (DE3) and Rosetta gami pLysS.

Tricine 16% gels loaded with purified samples from transformed P.pastoris cultures. The band representing Der f 2 was visualized after silver staining.

Third lane = Der f 2 (16 kDa olecular weight)

Fourth Lane = SeeBlue® Plus2 Pre-Stained