Table 2C.

Peptides influencing Aβ aggregation and toxicity. β-sheet breaking peptides based on proline

Name	Sequence	Description	D/L	Results	Reference
iAβ5	Ac-LPFFD-amid	Proline β-sheet breaker	L/D	Aβ fibril inhibition and de-fibrillization in vitro. Reduction of plaque load and Aβ induced pathological processes in rat model and in AD tg mice. Improvement of rat spatial memory impairments	Soto et al., 1996; Soto et al., 1998; Poduslo et al., 1998; Sigurdsson et al., 2000; Permanne et al., 2002; Chacon et al., 2004 [68, 83-86, 135]
iAβ5	LPFFD-derivatives	Proline β-sheet breaker	L	Methylation of amide nitrogen increased in vitro and in vivo stability while maintaining iAβ5 activity in vitro	Adessi et al., 2003 [131]
iAβ5-PEG	LPFFD-PEG	Proline β-sheet breaker	L	Biological activity of iAβ5 (in vivo) is not affected by PEG. Aimed to improve pharmacological properties, especially in vivo degradation	Rocha et al., 2009 [136]
none	LPYFD	Proline β-sheet breaker	L	Decreased neurite degeneration, tau aggregation and cell viability reduction induced by Aβ	Datki et al., 2004 [87]
LPYFDa	LPYFDamid	Proline β-sheet breaker, amidated	L	Protects neurons in vitro and in vivo after intraperitonial administration to rat models	Szegedi et al., 2005; Juhász et al., 2009 [88, 89]

D/L: describes peptide conformation. Tg: transgenic. PEG: poly (ethylene glycol).