Table 1.

Screening of GAIs

GAI	Sequence	Potency	Cytotoxicity	Side effect
		Aggregation inhibitory activity (%)	Cell viability (%)	Effect on GAPDH activity (%)
1	SNASCTTNAL	53.1 $\pm$ 2.87	100 $\pm$ 2.43	104 $\pm$ 2.73
2	SLKIISNASCTTNALAPLAK	70.8 $\pm$ 1.89	16.2 $\pm$ 2.91∗,∗∗	$-$
3	SVKIISNASCTTNALAPLAK	80.1 $\pm$ 2.78	2.60 $\pm$ 0.22∗,∗∗	$-$
4	SLKIISNASCTTNALAPVAK	72.0 $\pm$ 2.11	9.06 $\pm$ 2.73∗,∗∗	$-$
5	SNASCTTNAL	$0$	$-$	$-$
6	SNASCTTNSL	25.0 $\pm$ 2.87	100 $\pm$ 3.52	94.5 $\pm$ 9.77
7	SNASATTNCL	$0$	$-$	$-$
8	SNASCTTNDL	58.7 $\pm$ 2.55	102 $\pm$ 3.68	99.5 $\pm$ 2.68
9	SNASCTTNFL	22.8 $\pm$ 2.44	101 $\pm$ 3.18	104 $\pm$ 1.60
10	SNASCTTNGL	56.4 $\pm$ 2.77	102 $\pm$ 1.28	97.0 $\pm$ 3.32
11	SCTTNAL	48.3 $\pm$ 1.06	101 $\pm$ 3.28	106 $\pm$ 3.32
12	SNASCTT	46.2 $\pm$ 2.91	100 $\pm$ 3.01	98.8 $\pm$ 5.01
13	SCTT	89.6 $\pm$ 2.79	101 $\pm$ 3.05	97.6 $\pm$ 6.14
14	NASC	74.9 $\pm$ 3.00	101 $\pm$ 1.44	96.5 $\pm$ 6.15
15	ASCT	72.2 $\pm$ 2.49	102 $\pm$ 1.12	98.0 $\pm$ 4.49
16	CTTN	70.8 $\pm$ 2.10	101 $\pm$ 1.24	96.1 $\pm$ 10.6
17	SCT	97.2 $\pm$ 1.88	101 $\pm$ 2.95	100 $\pm$ 1.19
18	ASC	80.3 $\pm$ 2.18	102 $\pm$ 2.95	109 $\pm$ 4.57
19	CTT	89.7 $\pm$ 2.56	101 $\pm$ 2.15	108 $\pm$ 4.80
20	ACT	83.4 $\pm$ 1.84	102 $\pm$ 1.85	103 $\pm$ 9.17
21	SCA	86.5 $\pm$ 2.56	101 $\pm$ 0.90	93.6 $\pm$ 8.71
GSH	ECG	43.3 $\pm$ 2.55	101 $\pm$ 3.17	98.5 $\pm$ 3.60

Twenty peptides (GAI-2–21) based on the amino acid sequence of GAI-1 were synthesized and evaluated with GAPDH aggregation inhibitory effect (potency), the effect on cell viability (cytotoxicity), and GAPDH activity (side effect). n = 4, mean ± S.D. ∗p < 0.05 and ∗∗p < 0.01, relative to the treatment with vehicle, as determined by Student’s t test. Endogenous cysteine-containing tripeptide glutathione (GSH) was examined (bottom row), as compared with GAI-17. ($-$) means “not determined.”