Figure 5.

In Vitro Binding Assay.

Purified recombinant proteins lacking transmembrane and C-terminal lumenal sequences, designated Δ(At)SRC2 and Δ(At)VAP, were incubated with agarose-immobilized specific (S; CYPIEPPPHH) and nonspecific (NS; CHQPLATEDY) peptides. Unbound proteins were recovered in the drain (D) and the wash (W) steps. Bound proteins were eluted (E) with a 2% SDS buffer and detected on an immunoblot using their corresponding antibodies.

(A) The binding reaction was performed in the presence of 75 mM NaCl for both Δ(At)SRC2 and Δ(At)VAP.

(B) The binding specificity of Δ(At)SRC2 was tested in 75, 150, and 250 mM NaCl as indicated.