Abstract

Amyloids are highly ordered protein aggregates, characterized by their elongated fibrillar architecture that is stabilized by a β-sheet structural core. The amyloid conformation has been classically associated to protein misfolding disorders such as Alzheimer’s and Parkinson’s diseases among others but in the past two decades reports on novel functional roles for these aggregates have increasingly emerged. Their unique mechanical properties have also positioned amyloids as promising novel bionanomaterials. The recent discover that rational design of amyloidogenic peptide sequences can yield catalytically active amyloids have opened up new venues for biotechnological and biological research. The observed activities typically emerges by alternating polar and apolar residues that enable the coordination of divalent metals on the polar side, giving rise to a metal-peptide amyloid arrangement that structurally mimic the active site of certain enzymes. Previous work from our group showed that the assembly into amyloids of a peptide containing the catalytic sequence from a nucleotydiltransferase (SDIDVFI) is dependent on coordination of divalent metals magnesium (Mg+2) or manganese (Mn+2) ions. In this work, we showed that this peptide exhibits an ATPase-like activity that is observed only for the amyloid-Mn+2 complex. We performed a kinetic characterization of the activity using different nucleotides in order to gain details about substrate specificity. The results from our work will provide novel insights on amyloid reactivity and its potential impact on diverse aspects such as amyloid toxicity and molecular evolution.