The normal cellular role of α-synuclein is of potential importance in understanding diseases in which an aggregated form of the protein has been implicated. A potential loss or change in the normal function of α-synuclein could play a role in the aetiology of diseases such as Parkinson's disease. Recently, it has been suggested that α-synuclein could cause the enzymatic reduction of iron and a cellular increase in Fe(II) levels. Experiments were carried out to determine if such activity could be measured in vivo. Experiments with rats overexpressing human α-synuclein in nigral dopaminergic neurons demonstrated a correlation between α-synuclein expression and ferrireductase activity. Furthermore, studies on tissue from Parkinson's disease patient brains showed a significant decrease in ferrireductase activity, possibly due to deposition of large amounts of inactive protein. Cellular studies suggest that increase ferrireductase activity results in increased levels of dopamine metabolites and increased sensitivity to the toxicity of DOPAL. These findings demonstrate that α-synuclein ferrireductase activity is present in vivo and its alteration may play a role in neuron loss in disease.

α-突触核蛋白的正常细胞作用对于理解涉及蛋白质聚集形式的疾病具有潜在的重要性。α-突触核蛋白正常功能的潜在丧失或改变可能在诸如帕金森氏病等疾病的病因中起作用。最近，有人提出α-突触核蛋白可能引起铁的酶促还原和Fe（II）水平的细胞增加。进行实验以确定这种活性是否可以在体内测量。在大鼠多巴胺能神经元中过表达人α-突触核蛋白的大鼠进行的实验表明，α-突触核蛋白的表达与亚铁还原酶活性之间存在相关性。此外，对帕金森氏病患者大脑组织的研究表明，亚铁还原酶活性显着下降，这可能是由于大量非活性蛋白沉积所致。细胞研究表明，亚铁还原酶活性的提高导致多巴胺代谢产物的含量增加，并且对DOPAL毒性的敏感性增加。这些发现表明，α-突触核蛋白亚铁还原酶活性存在于体内，并且其改变可能在疾病的神经元丧失中起作用。