Fig. 2.

LTBP1 and LTBP3 can be cross-linked to fibrillin by TG2. (A) Schematic diagrams of the domain arrangements of LTBPs 1-4 and the C-terminal regions used in this study, referred to as CT1-4, respectively. These constructs along with the fibrillin1-PF3 region were expressed and purified from HEK293 cells. (B) SDS-PAGE gels, stained with Coomassie Blue, showing the fibrillin PF3 fragment and the C-terminal regions of LTBP1 (CT1), LTBP3 (CT3), LTBP2 (CT2) and LTBP4 (CT4) in the presence (+) and absence (-) of transglutaminase-2 (TG2). When incubated, complexes form between PF3-CT1 and PF3-CT3 (i) but not between PF3-CT2 and PF3-CT4 (ii). The two assays shown in (B) were performed at the same time, under the same conditions and with the same batch of TG2 but were run on separate gels.