Purity ~90% (SDS-PAGE). Neurophysin 1 specifically binds oxytocin.Oxytocin causes contraction of the smooth muscle of the uterus and of the mammary gland. Source: Recombinant protein corresponding to aa32-125 from human Oxytocin-neurophysin 1, fused to His-SUMO-Tag at N-terminal and fused to Myc-Tag at C-terminal, expressed in E. coli. Molecular Weight: ~29.6kD AA