The proteins α/β-SNAP are two related soluble and highly conserved proteins that bind to the fusion complex (SNARE complex), thus allowing the N-ethylmaleimide sensitive fusion protein NSF to bind to the complex. γ-SNAP binds directly to NSF and Gaf-1/Rip11, a protein of the Rab11 interacting family. In contrast to α/β-SNAP it does not interact directly with SNARE proteins and is not required for ER-Golgi transport. SNAP-proteins are abundantly expressed in all tissues. They are partially soluble, partially membrane-bound.