Chiral LVFFARK enantioselectively inhibits amyloid-β protein fibrillogenesis

摘要

The modulation of protein aggregation is involved not only in biochemical engineering processes,but also in in vivo biological events such as Alzheimer's disease(AD)that features amyloid-βprotein(Aβ)deposits.Inspired by the different pharmacological efficacy of enantiomers,taking heptapeptide LVFFARK(LK7)as an example,herein the chiral influence of peptide inhibitors on Aβfibrillogenesis and cytotoxicity was investigated by extensive biophysical and biological analyses.It was intriguing to find that although both LLK7 and D-LK7 could inhibit Aβaggregation in a concentration-dependent manner,it was the D-enan-tiomer that exhibited chirality preference and selectivity for modulation of Aβself-assembly.As com-pared with L-LK7 at the same conditions,D-LK7 showed significantly enhanced potency on suppressing cross-βsheet formation,fibrillar Aβaggregates deposition,Aβconformational transition,and Aβ-triggered neurotoxicity on cultured cells.For instance,L.LK7 and D-LK7 rescued cells by increasing cell via-bility from 60%to 62%and 84%at 100μmolL^(-1),respectively.The chiral discrimination of L-LK7 and D-LK7 was further validated by the different elimination efficiency on amyloid accumulation in AD model nematodes.It is considered that the higher binding affinity of D-LK7 to Aβmonomers than that of L LK7 resulted in the stronger inhibition effect.This work provided new insights into understanding chiral-ity in the interaction with Aβand the consequent inhibitory effect,and would contribute to the design of anti-amyloid agents.