Amyloid beta peptides
Beta Amyloid peptides, also called Amyloid beta peptides (Abeta peptides) are the main component of amyloid peptide plaques in the brain of patients with Alzheimer’s disease. sb-PEPTIDE provides a broad range of chemically synthesized amyloid beta peptides for Alzheimer’s disease research. We supply Abeta peptides of different lengths and point-mutated versions. Do not hesitate to contact us for any information.
Amyloid Beta peptide (1-42)
Here is the specifications for Amyloid beta peptide (1-42).
|Sequence : DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA|
|MW : 4 514.08 Da (C203H311N55O60S)|
|Purity : > 95%|
|Counter-Ion : TFA Salts (see option TFA removal)|
|Delivery format : Freeze dried in propylene 2mL microtubes|
|Other Names : Beta-Amyloid peptide, β-Amyloid Peptide, AAA, ABETA, ABPP, AD1, APPI, CTFgamma, CVAP, PN-II, PN2, Amyloid beta A4 protein, preA4, protease nexin-II, peptidase nexin-II, alzheimer disease amyloid protein, cerebral vascular amyloid peptide, APP, Amyloid Precursor Protein, 107761-42-2|
|Peptide Solubility Guideline|
|Bulk peptide quantities available|
1- Murphy MP, LeVine H 3rd. J Alzheimers Dis. 2010
Alzheimer’s disease (AD) pathogenesis is widely believed to be driven by the production and deposition of the β-amyloid peptide (Aβ). For many years, investigators have been puzzled by the weak to nonexistent correlation between the amount of neuritic plaque pathology in the human brain and the degree of clinical dementia. Recent advances in our understanding of the development of amyloid pathology have helped solve this mystery. Substantial evidence now indicates that the solubility of Aβ peptide, and the quantity of Aβ in different pools, may be more closely related to disease state. The composition of these pools of β-amyloid peptides reflects different populations of amyloid deposits, and has definite correlates with the clinical status of the patient. Imaging technologies, including new amyloid imaging agents based on the chemical structure of histologic dyes, are now making it possible to track amyloid pathology along with disease progression in the living patient. Interestingly, these approaches indicate that the Aβ deposited in AD is different from that found in animal models. In general, deposited Aβ is more easily cleared from the brain in animal models, and does not show the same physical and biochemical characteristics as the amyloid found in AD. This raises important issues regarding the development and testing of future therapeutic agents.
2- Gouras GK, Olsson TT, Hansson O. Neurotherapeutics. 2015
Many lines of evidence support that β-amyloid (Aβ) peptides play an important role in Alzheimer’s disease (AD), the most common cause of dementia. But despite much effort the molecular mechanisms of how Aβ peptide contributes to AD remain unclear. While Amyloid Beta peptide is generated from its precursor protein throughout life, the peptide is best known as the main component of amyloid plaques, the neuropathological hallmark of AD. Reduction in Aβ has been the major target of recent experimental therapies against AD. Unfortunately, human clinical trials targeting Aβ have not shown the hoped-for benefits. Thus, doubts have been growing about the role of Aβ peptide as a therapeutic target. Here we review evidence supporting the involvement of Aβ peptide in AD, highlight the importance of differentiating between various forms of Aβ, and suggest that a better understanding of Aβ’s precise pathophysiological role in the disease is important for correctly targeting it for potential future therapy.
3- Kopec KK, Carroll RT. J Neurochem. 1998
Beta-amyloid (A beta) peptides are a key component of the senile plaques that characterize Alzheimer’s disease. Cytokine-producing microglia have been shown to be intimately associated with amyloid deposits and have also been implicated as scavengers responsible for clearing A beta deposits. However, little is known about the initial activation of these microglia or the effect of A beta on phagocytosis. Murine BV-2 microglia were used to assess the effect of synthetic A beta 1-42 on phagocytosis by quantifying uptake of fluorescent microspheres, acetylated low-density lipoproteins, and zymosan particles by flow cytometry. A beta 1-42 stimulated microglial phagocytosis in a time- and dose-dependent manner. A beta fibrils produced the greatest potentiation, and once activated, phagocytosis remained elevated after removal of A beta from the cultures. A beta-stimulated phagocytosis could be blocked if proteoglycans were first complexed to A beta fibrils. These data suggest that A beta fibrils act as an immune signal to stimulate microglial phagocytosis and that extracellular matrix molecules may modify Amyloid beta peptide function.
4- Miyashita N, Straub JE, Thirumalai D. J Am Chem Soc. 2009
Structures of beta-amyloid peptide 1-40, 1-42, and 1-55-the 672-726 fragment of APP-in a membrane environment with implications for interactions with gamma-secretase
Aggregation of Amyloid beta (Abeta) peptide has been linked to the neurodegenerative Alzheimer’s Disease and implicated in other amyloid diseases including cerebral amyloid angiopathy. Abeta peptide is generated by cleavage of the amyloid precursor protein (APP) by transmembrane proteases. It is crucial to determine the structures of beta-amyloid peptides in a membrane to provide a molecular basis for the cleavage mechanism. We report the structures of amyloid beta peptide (Abeta(1-40) and Abeta(1-42)) as well as the 672-726 fragment of APP (referred to as Abeta(1-55)) in a membrane environment determined by replica-exchange molecular dynamics simulation. Abeta(1-40) is found to have two helical domains A (13-22) and B(30-35) and a type I beta-turn at 23-27. The peptide is localized at the interface between membrane and solvent. Substantial fluctuations in domain A are observed. The dominant simulated tertiary structure of Abeta(1-40) is observed to be similar to the simulated Abeta(1-42) structure. However, there are differences observed in the overall conformational ensemble, as characterized by the two-dimensional free energy surfaces. The fragment of APP (Abeta(1-55)) is observed to have a long transmembrane helix. The position of the transmembrane region and ensemble of membrane structures are elucidated. The conformational transition between the transmembrane Abeta(1-55) structure, prior to cleavage, and the Abeta(1-40) structure, following cleavage, is proposed.