SNARE proteins are soluble N-ethylmaleimide-sensitive factor activating protein receptor proteins that are membrane-bound and contain Heptad repeats. These SNARE proteins are needed for the fusion of vesicles with the plasma membrane. When the SNARE proteins come together, they are able to pull the vesicle membrane and plasma membrane closer together by forming a tight group of alpha helices. Only around two or three SNARE complexes are needed to allow a vesicle to fuse with the plasma membrane. In order for SNARE proteins to aid the fusion of vesicles to the membrane, a number of other proteins are needed to help the process take place. SNARE proteins have a conserved amino acid sequence called the 'SNARE' motif. Overall, there are four families of SNARE proteins, and when two different families come together they form a stable core complex. This complex can only be separated by boiling it with SDS (sodium dodecyl sulfonate). - ↑ Duman J, Forte J. What is the role of SNARE proteins in membrane fusion?. AJP: Cell Physiology [Internet]. 2003;285(2):C237-C249. Available from: https://www.ncbi.nlm.nih.gov/pubmed/12842832- ↑ Goodsell D. PDB-101: SNARE Proteins [Internet]. Pdb101.rcsb.org. 2017 [cited 3 December 2017]. Available from: http://pdb101.rcsb.org/motm/167- ↑ Wang Z. Molecular mechanisms of neurotransmitter release. [Place of publication not identified]: Humana; 2014.