Fig 5.

TPV-15L binds to heparin. (A) Unfractionated baculovirus-expressed TPV-15Lmyc/His slot blots. Three identical slot blots were performed, each aspirating heparin (1a, 3a, and 5a), TPV-15Lmyc/His (2a, 4a, and 6a), BSA (1b, 3b, and 5b), and uninfected Sf21 cell supernatant (Neg, 2b, 4b, and 6b). Blots were blocked and then incubated in either TPV-15Lmyc/His supernatant, TPV-2Lmyc/His supernatant or uninfected Sf21 cell supernatant as shown. Membranes were washed and detected using anti-myc antibodies. (B) TPV-15L isolated from His column was dialyzed with PBS, passed through a heparin column, and eluted with an increasing gradient of NaCl to assess relative affinity. In comparison, hNRG1elutes at 0.45 to 0.65 M NaCl on an identical column, suggesting a slightly weaker but comparable interaction with heparin.