FIGURE 2.
Dysferlin directly binds syntaxin 4 and SNAP-23 as determined by fluorescence anisotropy. A, representative SDS gel showing purity of recombinant dysferlin proteins. Purified C2 domains are shown on the left and with the dysferlin construct possessing the entire cytoplasmic region of the protein (lacking only the transmembrane domain) shown on the right. a.a., amino acids; MBP, maltose-binding protein. B, dose-response curve for the addition of the full-length cytoplasmic region of dysferlin (amino acids 1–1965) to a sample containing FITC-labeled syntaxin 4 lacking a transmembrane domain. C, dose-response curves for C2ABC and C2DEFG region of dysferlin show a progressive increase in binding for the H3 domain of syntaxin 4. D, titration curves for FITC-labeled SNAP-23 mixed with either the C2ABC or C2DEFG constructs of dysferlin. Measurements were collected at 23 °C. Error bars represent S.D. n = 3.