RESUMO
Objective To explore the cooperative effect from β-propensity of amyloidogenic peptides on amyloid nucleation and its related products. Methods Based on a coarse-grained model for amyloidogenic peptides containing two states ( a soluble state and a β-sheet-forming state), with the consideration of two kinds of cooperative effects on β-propensity of peptides ( inhibiting and promoting the conformational conversion of peptides), the regulation of cooperative effects from amyloidogenic peptides on amyloid nucleation was analyzed through Monte Carlo simulations. Results In the case of the cooperative effect inhibiting the conformational conversion of peptides, amyloid nucleation occurred only within a certain interval of the peptide concentration, as well as inside the oligomers with certain sizes. Besides, the coexistence of on-pathway and off-pathway oligomers was observed. In the case of the cooperative effect promoting the conformational conversion of peptides, the β-sheet protofibril could be observed at physiological concentration as low as 4 μmol / L. Conclusions In this study, a more realistic coarse-grained model for amyloidogenic peptides was developed by introducing the cooperative effects of local concentration on β-propensity of amyloidogenic peptides, with observation of some intriguing phenomena not reported in previous simulations. The research findings not only improve current understandings about the mechanism of amyloid formation, but also provide theoretic references for the therapeutic strategies for curing neurodegenerative diseases