1. Soluble NSF attachment (accessory) proteins (SNAPs) that are involved in the control of vesicle transport. SNAPα (295 aa) and SNAPγ are found in a wide range of tissues. SNAPβ is a brain-specific isoform of SNAPα. SNAPs and NSF bind to SNAREs. SNAP-25 (synaptosomal-associated 25-kDa protein, 206 aa) is involved in the regulation of neurotransmitter release. See SNIP (2).