By searching databases for sequences similar to the long coiled-coil region of alpha-taxilin, followed by PCR of a brain cDNA library, Nogami et al. (2004) cloned TXLNB. The deduced 684-amino acid protein has a calculated molecular mass of 76.5 kD. The long coiled-coil region of TXLNB spans amino acids 140 to 456. Western blot analysis of rat tissues detected abundant expression in skeletal muscle and heart.

Using C-terminally truncated syntaxins for in vitro protein pull-down assays, Nogami et al. (2004) demonstrated that epitope-tagged human TXLNB and native rat Txlnb bound to syntaxin 1A (STX1A) and, to a lesser extent, to STX4A (186591), but not to STX3A, STX7, or STX8 . Binding of TXLNB to truncated STX1A and STX4A was dose-dependent and saturable.