Position 30 of alpha-synuclein is a Parkinson's disease locus. A30P was among the first SNCA mutations linked to familial disease, and an A30G variant has since been described in a separate kindred. This peptide brackets that position, covering residues 21 to 40. How A30P causes disease is instructive, because it does not act by making the protein stickier. The substitution sits in the lipid-binding repeat region and weakens helical association with membranes, shifting the balance toward unbound protein. Pathology follows indirectly from that redistribution rather than from a direct change to the aggregation core, which is why the N-terminal region is studied as a distinct problem from the hydrophobic segment. Practically, a peptide over this window serves as the wild-type reference when asking whether an antibody, aptamer or binding protein discriminates the variant sequence. Paired with the mutant version it reports specificity directly; used alone it establishes baseline recognition of the unmutated stretch. Biotinylation with a long-chain spacer suits it to streptavidin capture formats. | 