Part:BBa_K632002

INP-Silicatein

The silicatein gene has been successfully fused to an existent ice nucleation protein (BBa_K265009). Gel electrophoresis and DNA sequencing both suggest the fusion product is the correct size, frame, and orientation. Silicatein functional assay was performed to verify the activity of silicatein, and the results indicate the silicatein is enzymatically active.

Usage and Biology

The INP-Silicatein fusion protein is a chimeric protein with the outer membrane associated domain (N-terminal domain) of ice nucleation protein fused to silicatein which is capable of polymerizing silicic acid monomers. The 2011 University of Minnesota iGEM team generated the following data regarding this part:

Figure 1. (left) A standard curve for the functional silicatein assay described at [http://2011.igem.org/Team:Minnesota/Protocols 2011 University of Minnesota iGEM Protocols]. The standard curve shows good linear correlation and represents data from three trials. (Right) Data obtained from cultures of cells expressing INP and INP-Silicatein. As can be seen, as cell culture volume increases, the amount of silicic acid monomers remaining in the supernatent decreases indicating an increase in silicatein activity. Cells expressing only INP with an active silicatein domain do not show an increase in silicatein activity as cell volume increases suggesting that endogenous cellular components and INP do not cause an appreciable response to the enzymatic assay. Figure 2. Tubes showing the results of the silicatein functional assay. The leftmost vial contained no cells in the incubation culture which is reflected in the darker blue tint of the supernatent. This indicates that there is a higher concentration of monomers remaining in solution and therefore negligible silicatein activity. The rightmost vial shows a much reduced degree of response to the functional silicatein assay which indicates a higher degree of silicatein activity in the incubation culture. These data are consistent with our expectations.