Amyloid beta-peptide (25-35)

Amyloid beta-peptide (25-35) is the fragment Aβ (25-35) of the Alzheimer's amyloid β-peptide. Which has shown neurotoxic activities in cultured cells. The amino acid sequence of Aβ (25-35) peptide is NH2-Gly-Ser-Asn-Lys-Gly-Ala-Ile-Ile-Gly-Leu-Met-COOH, where the first Gly represents the amino acid 25 and the last Met represents the amino acid 35 and it is also investigated in gel state for the first time. Amyloid beta-peptide (25-35) induces apoptotic effects on isolated brain mitochondria and the redox state of methionine-35, plays a key role in the induction of programmed cellular death pathways and toxic events. Comparative studies are also carried out using vibrational absorption and ECD. The conformational preference of Aβ (25-35) peptide film is also investigated using vibrational absorption and VCD spectroscopy.The Alzheimer' s disease (AD) model group present with spatial learning and memory impairments. CDS and donepezil administration significantly ameliorate the Aβ25–35 peptide-induced memory impairment in both Morris water maze (P < 0.05) and passive avoidance task (P < 0.01) compared to the AD model group[3]. Rats are injected with Aβ25–35 peptide intracerebroventricularly and compound Danshen (CDS) are subsequently administered once daily for 23 days. Rats' behavior is monitored using Morris water maze and passive avoidance. Real time PCR and Western blotting are used in determining amyloid precursor protein (APP), β-site APP cleaved enzyme-1 (BACE1), Presenilin-1 (PS1), Insulin-degrading enzyme (IDE) and neprilysin (NEP) in hippocampus.