FIG. 4.

Patient-derived SMN mutations decrease NS2 binding. Truncated and point-mutated SMN displays a reduced affinity for NS2. SMN wild type (WT), SMN point mutations (type I mutations, 274 and 279; type II mutation, 272), or SMNΔ7 was immobilized on a sensor chip using an anti-SMN monoclonal antibody and probed with recombinant NS2. Truncated and point-mutated SMN displays a reduced ability to self associate (open bars). Wild-type monomeric SMN covalently bound to a sensor chip was exposed to truncated and point-mutated SMN to determine the various proteins' ability to dimerize. Binding values are represented as response units (RU).