Difference between revisions of "Part:BBa K2332051"

Latest revision as of 18:24, 24 October 2017

Intimin'-SpyCatcher (constitutive)

This biobrick is the fusion of a truncated version of Intimin (159kDa), an outer membrane surface protein, and SpyCatcher (138 amino acids, 15 kDa) for the cell surface display of SpyCatcher. To trigger cell adhesion, we decided to make use of the SpyTag and SpyCatcher, two binding partners that form rapid covalent bonds, fused to outer membrane surface proteins. SpyTag (13 amino acids) and SpyCatcher (138 amino acids, 15 kDa) come from CnaB2 (immunoglobulin-llike collagen adhesin domain) of the FbaB protein, found in the invasive strains of S. pyogenes. The reactive lysine in SpyCatcher forms an isopeptide covalent bond with the aspartate residue in SpyTag. We decided to fuse SpyTag and SpyCatcher to outer membrane surface proteins in distinct cell populations that would then aggregate once mixed together. Intimin'-SpyCatcher and Intimin'-SpyTag will be placed under the control of our blue light inducible promoter Pblind to guide cell structure formation using blue light along with our SpyTag variants.

Usage and Biology

Cells transformed with this construct will express a truncated version of intimin (denoted intimin') fused to SpyCatcher. As shown in figure 1, Intimin is an outer membrane protein and thus proteins fused to its N termini will be displayed on the cell surface. The reactive aspartate residue (Asp) in SpyTag is able to form a spontaneous and irreversible strong isopeptide bond with the lysine residue (Lys) in SpyCatcher. Thus, when two cell lines expressing either Intimin'-SpyTag or Intimin'-SpyCatcher, are mixed together, cells will aggregate.

Figure 1: Cell surface display of SpyTag and SpyCatcher for cell aggregation.

Sequence and Features