Figure 7.

Replacement of the region between the 6^th and 7^th cysteine residues in the 3^rd 8-Cys repeat of LTBP-2 with that of LTBP-1 results in gain-of-function of TGF-β-β1•LAP binding. Wild-type LTBP -1 and -2 constructs, pJS-4 and pJS-24, respectively, as well as construct L2GAIN were transfected together with TGF-β1 cDNA to 293T cells. The proteins from conditioned medium were separated by 7.5% PAGEs and analyzed for covalent complex formation between the proteins coded by LTBP constructs and β1•LAP. Brackets on the right indicate the free or complexed β1•LAP forms. Secretion of the proteins coded by LTBP constructs was verified by 4–15% gradient PAGEs followed by immunoblotting with anti-HA antibody (lower panel).