Figure 1. The recombinant transforming growth factor beta-induced protein (TGFBIp) was successfully expressed using mammalian cells. A: The TGFBI cDNA with various motifs were used for the expression in mammalian cells. "(His)6": polyhistidine tag; "Strep II": strep II tag; "Fas": Fasciclin-like domain; "RGD": arginine-glycine-aspartate motif. B: Purified recombinant TGFBIp were analyzed on a 12% SDS-PAGE gel. “St’d”: molecular markers; lane 1: single-tagged (His)₆-TGFBIp; lane 2: double-tagged (His)₆-TGFBIp-(Strep II) protein. The amyloid fibril formation of recombinant TGFBIp was obtained after incubation in 1× Tris-buffered saline at 37 °C for one week, as demonstrated by C: thioflavin (ThT) fluorescence spectroscopy and by D: electron microscopy (75,000× magnification).