Here, we studied the utility of the experimental system in which heterogeneous mProVII variants were formed by co-assembly of α chains fused with RFP or GFP. Although the native procollagen VII is characterized by the presence of a relatively long triple-helical domain, studies by Chen et al. and our own research have demonstrated that mini-procollagen VII variants consisting of a truncated triple-helical domain flanked by intact NC1 and NC2 domains are thermostable, have correct structure, and are properly secreted from
ha tag peptide [18], [19] and [20]. In our current studies the rationale for tagging the individual α chains with different fluorescent proteins was to facilitate selection of recombinant mProVII molecules that consist of WT and mutant chains harboring single amino
acid substitutions found in patients with DEB [18]. An important aspect of such an experimental design was to determine if the presence of bulky fluorescent proteins at the C-termini of individual mProVII chains could interfere with their proper folding into triple-helical structure and their secretion into the extracellular space.
