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β-Amyloid (1-42)由 42 个氨基酸组成的肽，其在阿尔茨海默病的发病机制中起关键作用。

淀粉样β-肽（1-42）（Aβ42）是一种42个氨基酸的肽，在阿尔茨海默病（AD）的发病机制中起着关键作用。

发病机制中的主要有害作用可能由Aβ42调节，Aβ42作为基因转录的阻遏物或激活物，导致进一步的突触功能损伤和神经元变性。

当Aβ42升高到2.5μM时，SH-SY5Y细胞的活力降低到65%。使用染色质免疫沉淀（ChIP）和qRT-PCR分析，用具有LRP1和KAI1启动子的Aβ42相关肽处理SH-SY5Y细胞并增加APP mRNA水平，而无毒的Aβ42G33A肽作为大量存在于细胞核中的对照组，对mRNA表达没有任何影响。与几种不同长度的肽相比，Aβ42处理后其前体基因APP的转录和表达独家增加。

β42被认为是调节细胞功能的重要作用。

Amyloid β-Peptide (1-42) (Aβ42) human is a 42-amino acid peptide that plays a key role in the pathogenesis of Alzheimer disease (AD).

The main deleterious effects in the pathogenesis are probably regulated by Aβ42, which acts as a repressor or activator of gene transcription causing further synaptic function damage and neuronal degeneration .

Aβ42 reduced the viability of SH-SY5Y cells to 65% when it rose to 2.5 μM. Using the chromatin immunoprecipitation (ChIP) and qRT-PCR assays, treatment of SH-SY5Y cells with Aβ42 associated peptide with both LRP1 and KAI1 promoters and increased APP mRNA levels, while the nontoxic Aβ42 G33A peptide, as a control group which presents in the nucleus abundantly, did not have any influence on mRNA expression. The exclusive increase of transcription and expression of its precursor gene APP was found with the treatment of Aβ42, compared with several different lengths of peptides .

Aβ42 is regarded as an important role in modulating the function of voltage-gated Ca2+- and K+-channels of the surface neuronal membranes. Application of Aβ42 with desired concentrations (1 to 10 μM) in the perfusing medium had no impact on delayed rectifier K+-current and leakage current, while enhanced inactivation of Ca2+-current and blocked Ca2+-dependent K+-current .

β1-42，淀粉样前体蛋白的42个残基片段，已被发现是阿尔茨海默病和晚期唐氏综合征患者大脑中形成的老年斑的主要成分。Aβ1-42在生理pH值下容易形成神经毒性低聚物。另一方面，该肽具有抗菌活性。该肽的序列对应于人、牛、犬、猫、绵羊、豚鼠和兔Aβ42的序列。该肽已被用于通过荧光相关光谱检测阿尔茨海默病患者脑脊液中的淀粉样β蛋白多聚体。关于Aβ1-42单体和原纤维制备的详细描述，请参阅Jan、Hartley和Lashuel、Stine等人（2011）以及Broersen及其同事的论文。Ryan等人的研究结果表明，10%的氨比HFIP更有效地分解Aβ42。

Aβ 1-42, 42-residue fragment of amyloid precursor protein, has been found to be a major constituent of the senile plaques formed in the brains of patients with Alzheimer’s disease and late Down’s syndrome. Aβ 1-42 readily forms neurotoxic oligomers at physiological pH. On the other hand, the peptide shows antimicrobial activity. The sequence of this peptide corresponds to the sequence of human, bovine, canine, feline, ovine, guinea pig, and rabbit Aβ42. The peptide has been used to detect amyloid β-protein multimers in the cerebrospinal fluid of Alzheimer’s disease patients through fluorescence correlation spectroscopy. For detailed descriptions of the preparation of Aβ 1-42 monomers and protofibrils please see the papers of Jan, Hartley, and Lashuel, Stine et al. (2011), and of Broersen and colleagues. The findings of Ryan et al. indicate that 10% ammonia disaggregates Aβ42 more efficiently than HFIP.

β-Amyloid (1-42) (Amyloid β-peptide (1-42)), human，一种未经 HFIP 处理过的由 42 个氨基酸组成的肽，是一种具有脑渗透性的淀粉样蛋白片段，可用于阿尔茨海默病和唐氏综合征的研究。β-Amyloid (1-42), human 以单体形式存在时具有抗氧化和神经保护作用。β-Amyloid (1-42), human 在经过 HFIP 单体化处理和用 DMSO 溶成母液后，一方面在 4 ℃ 孵育形成可溶性寡聚体 (AβOs)，具有突触毒性和神经毒性；另一方面，可在 37℃ 孵育形成不溶性纤维，神经毒性较低，参与氧化损伤过程。Aβ42 寡聚体可与多种神经元表面受体 (如 PrPc、mGluR5、NMDA 受体等) 结合，通过激活下游信号通路引发氧化应激、钙稳态失衡和突触毒性，导致神经元功能障碍和死亡。

Amyloid-β peptide (Aβ)被认为是阿尔茨海默病发病机制中的关键因素。研究表明，Aβ能够调控神经元表面膜上电压门控Са2+通道和K+通道的功能[2- 6,8-13,15]。这种调节作用主要通过三种机制实现：1）Aβ与通道蛋白的直接相互作用；2）通过调节通道蛋白磷酸化水平产生的间接效应；3）激活基因组并增加膜通道蛋白密度。尽管该领域已有大量研究，但仍有诸多未解之谜。特别是关于Aβ对Ca2+通道失活及Ca2+激活的K+通道电导的影响机制仍不明确。

FA 的失调与阿尔茨海默病（AD）的发展密切相关。研究发现，阿尔茨海默病患者及动物模型中FA水平升高会引发认知功能障碍，但其具体作用机制仍不明确。最新研究揭示：淀粉样蛋白β（Aβ）丝氨酸8/26位点的氧化去甲基化会诱导FA生成，且FA与Aβ单体β转角处的赖氨酸28残基交联形成Aβ二聚体，从而加速体外实验中的Aβ寡聚化和纤维化过程。值得注意的是，当Aβ42突变体在丝氨酸8/26和赖氨酸28位点发生突变时，其自身聚集能力被完全抑制。此外，Aβ通过抑制甲醛脱氢酶（FDH）活性导致FA积累，而过量的FA则会通过促进Aβ寡聚体和纤维形成，在体外和体内实验中双重刺激Aβ聚集。研究发现，使用甲醛清除剂硫酸氢钠（NaHSO3）或辅酶Q10降解FA，可有效抑制Aβ聚集、减轻神经毒性，并改善APP/PS1小鼠的认知功能。本研究证实内源性FA对Aβ自聚集具有关键作用，清除FA或可成为治疗AD的有效策略。

FA 的降解可减少Aβ蛋白聚集并改善APP/PS1小鼠的记忆缺陷。a通过气相色谱-串联质谱联用技术（GC-MS/MS）检测辅酶Q10与FA的化学反应。b通过活体动物成像系统使用NaFA荧光成像检测脑内FA水平。

参考文献

[1]. Solntseva EI, et al. Impact of amyloid-β peptide (1-42) on voltage-gated ion currents in molluscan neurons. Bull Exp Biol Med. 2011 Oct;151(6):671-4.  

[2]. Barucker C, et al. Nuclear translocation uncovers the amyloid peptide Aβ42 as a regulator of gene transcription. J Biol Chem. 2014 Jul 18;289(29):20182-91.  

[3]. Stefania Sabella, et al. Capillary electrophoresis studies on the aggregation process of beta-amyloid 1-42 and 1-40 peptides. Electrophoresis. 2004 Oct;25(18-19):3186-94.  

[4]. Porzoor A, et al. Pretreatment of chemically-synthesized Aβ42 affects its biological activity in yeast. Prion. 2014;8(6):404-10.  

[5]. Zou K, et al. A novel function of monomeric amyloid beta-protein serving as an antioxidant molecule against metal-induced oxidative damage. J Neurosci. 2002 Jun 15;22(12):4833-41.

[6]. Peters C, et al. Alzheimer's Aβ interacts with cellular prion protein inducing neuronal membrane damage and synaptotoxicity. Neurobiol Aging. 2015 Mar;36(3):1369-77.  

[7]. Yao ZX, et al. Function of beta-amyloid in cholesterol transport: a lead to neurotoxicity. FASEB J. 2002 Oct;16(12):1677-9.

[8]. Jancsó G, et al. Beta-amyloid (1-42) peptide impairs blood-brain barrier function after intracarotid infusion in rats. Neurosci Lett. 1998 Sep 4;253(2):139-41.  

[9]. Bourgade K, et al. β-Amyloid peptides display protective activity against the human Alzheimer's disease-associated herpes simplex virus-1. Biogerontology. 2015 Feb;16(1):85-98.  

[10]. Fu L, et al. Comparison of neurotoxicity of different aggregated forms of Aβ40, Aβ42 and Aβ43 in cell cultures. J Pept Sci. 2017 Mar;23(3):245-251.  

[11]. Wang H, et al. Amyloid-beta1-42 induces reactive oxygen species-mediated autophagic cell death in U87 and SH-SY5Y cells. J Alzheimers Dis. 2010;21(2):597-610.  

[12]. Fei X, et al. Degradation of FA reduces Aβ neurotoxicity and Alzheimer-related phenotypes. Mol Psychiatry. 2021 Oct;26(10):5578-5591.  

"Beta Amyloid peptides, also called Amyloid beta peptides (Abeta peptides) are the main component of amyloid peptide plaques in the brain of patients with Alzheimers disease. sb-PEPTIDE provides a broad range of chemically synthesized\xa0amyloid beta peptides\xa0for Alzheimers disease research. We supply Abeta peptides of different lengths and point-mutated versions. Do not hesitate to contact us for any information."

"Key subunit of extracellular plaques found in the brains of patients with Alzheimers disease; Hydrochloride salt"

"Amyloid β-Protein (1-42) is a fragment of the amyloid beta protein that is thought to be a major contributor to the development of Alzheimers disease. Amyloid β-Protein (1-42) has been shown to have neuroprotective effects, as it reduces cell death in the brain and preserves memory. It binds to the β-catenin protein in neurons and protects against oxidative stress by reducing production of reactive oxygen species. This molecule also reduces microglia activation and tnf-α levels, which may reduce inflammation. Amyloid β-Protein (1-42) is found in plants such as pueraria lobata, and has been used for centuries in traditional Chinese medicine for its anti-inflammatory properties."

"Key subunit of extracellular plaques found in the brains of patients with Alzheimers disease. TFA salt; 95%."

Amyloid beta-protein (Aβ) is a peptide that is found in the human brain. It is one of the major components of amyloid plaque, which are deposits of a protein fragment in the brain that form as a result of aging and Alzheimer’s disease. It is produced by cleavage of the amyloid precursor protein (APP). Aβ has been shown to be toxic to cells, causing them to die. This toxicity may be due to its ability to inhibit ATP production and increase oxidative stress. Aβ can also induce apoptosis by binding to receptors on cell surfaces and activating intracellular signaling pathways. These events lead to activation of caspases, which are proteolytic enzymes that contribute to programmed cell death.

"Amyloid β-peptide (Aβ) has been identified as the key subunit of the extracellular plaques found in the brains of patients with Alzheimers disease (AD) and Downs syndrome (DS). Aβ has therefore been extensively studied as a potential target for treatment of AD.Aβ is formed from the cleavage of the large, transmembrane protein- APP (amyloid precursor protein). Cleavage of APP by β- and then γ-secretases results in the formation of Aβ. Aβ can aggregate to produce amyloid-β oligomers, which are thought to be highly neurotoxic. Over time Aβ can further aggregate to produce the characteristic senile plaques present in AD and DS.Aβ can be degraded by enzymes such as neprilysin, insulin degrading enzyme or endothelin converting enzyme. At physiological levels Aβ may be involved in controlling synaptic activity and neuronal survival."