Difference between revisions of "Part:BBa K2235011"

Revision as of 10:41, 28 October 2017

Sialidase enzyme coding composite N terminally attached to secretion system type 1

Usage and Biology

We used an already existing biobrick for HylA E.coli secretion system (BBa_K1166002) to secrete our sialidase from the iGEM 2017 distribution kit.

Characterization

Important Parameter

Purification and Identification

Figure 8: SDS-PAGE gel and a protein ladder. From left to right: protein ladder, following four are IMAC purification fractions of a control that wasn’t induced with IPTG, the last four show the IPTG induced sample fractions.

The newly cloned plasmid was transformed into E.coli and expression in flask was induced with 0.5 mM IPTG. The enzyme was extracted from the medium using IMAC purification. SDS-PAGE results (figure 8) shows no secretion of a protein resembling the correct size (≈ 55 kDa).

Ligation of sialidase insert into secretion device

Figure 7: Agarose gel. From left to right: DNA ladder, the next five are digested BBa_K2235011 plasmids.

Firstly, we removed the stop codon at the end of the sialidase gblock sequence using PCR and thereafter cloned sialidase without the stop codon upstream of the secretion system (BBa_K2235011). To confirm successful cloning, we double digested the plasmid (figure 7). Two bands were observed, one at ~7000 bp, corresponding to the size of T7 promoter-RBS-Sialidase-HylA E.coli secretion system, and one at ~2000 bp, corresponding to the size of the plasmid backbone.

References

Sequence and Features