Beta-Synuclein

β-synuclein is a member of the synuclein protein family, the other two members being α and γ-synuclein, each protein being coded for by a distinct but related gene. α-synuclein was originally isolated as a major synaptic vesicle associated protein from the electric organ of the fish Torpedo, and direct homologues of α-synuclein are found in all vertebrates. Later work connected α-synuclein expression with several human brain pathologies, so that it is a major component of the Lewy bodies of Parkinson’s disease. β-synuclein was isolated as a component of normal and diseased human brain as a protein clearly related to but distinct from α-synuclein. The human β-synuclein molecule is 134 amino acids in size compared to 140 amino acids for α-synuclein, and the N-terminal halves of the two molecules are virtually identical while the C-terminal regions is more variable.