Misfolding and aggregation of a-synuclein (AS) protein are considered to be causative factors for Parkinson's disease. Herein, we describe molecular dynamics simulations of aggregated AS with βC-EGCG to better characterize the detailed conformational effects on their inhibitory action. Our results indicate that the binding of βC-EGCG disrupt the β-sheet of aggregated AS structure and cause impairment of intermolecular interactions. Furthermore, the free energy landscape portrayed the effect of βC-EGCG directly impedes the formation of aggregated intermediate conformers in AS. Hence, our study could aid in the field of structure-based drug design against the AS disorder. © 2019 Elsevier B.V.