The primary biological target and mechanism of action of Amyloid beta-peptide(25-35) are complex and not fully attributed to a single receptor. It is known to exert its effects by interacting with various cellular components and inducing multiple downstream pathways. One key mechanism is its ability to induce apoptotic effects on isolated brain mitochondria. The redox state of methionine-35 within the peptide plays a critical role in the induction of programmed cell death pathways and toxic events. Furthermore, Aβ(25-35) has been shown to inhibit sodium/calcium exchange activity in rat and human brain plasma membrane vesicles. This disruption of ionic homeostasis is a significant contributor to its neurotoxicity. The peptide also induces neuroinflammation and oxidative stress. Its effects are multifaceted, involving the generation of reactive oxygen species, disruption of calcium signaling, and activation of apoptotic cascades. In cultured cells, it has shown clear neurotoxic activities, which is why it is a standard tool for inducing neurodegeneration in vitro.

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 amino acid 25, and the second Gly Represents amino acid 25. The last Met stands for amino acid 35. Amyloid β-peptide (25-35) was also investigated in gel form for the first time. Comparative investigations were also undertaken using vibration absorption and ECD. The structural preferences of Aβ(25-35) peptide films were also examined using vibrational absorption and VCD spectroscopy [1]. Amyloid β-peptide (25-35) can trigger apoptosis in isolated brain mitochondria and methionine-35 redox state, playing a vital role in generating programmed cell death pathways and toxic events [2]. Recommendations for Beta-Amyloid Aggregation (This is our suggested approach; it should be adjusted to suit your particular need as it simply offers guidelines). 1. Solid Aβ peptide should be dissolved in cold hexafluoro-2-propanol (HFIP). To achieve monomerization and randomization of the structure, incubate the peptides for a minimum of one hour at room temperature. 2. To get rid of HFIP, evaporate, and then store the resultant peptide in a film at -20 or -80°C. 3. The resultant membrane should be dissolved in 5 mM of anhydrous DMSO, vortexed, and diluted with buffer (serum- and phenol-red-free media) to the proper concentration. 4. After that, let the solution age for 48 hours at 4–8°C. After centrifuging the samples for 10 minutes at 4–8°C at 14,000 g, the supernatant contained soluble oligomers. For the studies, the supernatant was diluted 10-200 times. Different approaches are used based on the final application.
The in vitro activity of Amyloid beta-peptide(25-35) is characterized by its potent and well-documented neurotoxic effects. In cultured neuronal cells, such as primary cortical neurons or cell lines like PC12 or SH-SY5Y, Aβ(25-35) induces a concentration-dependent decrease in cell viability. It triggers a cascade of neurodegenerative events including the generation of reactive oxygen species (ROS), mitochondrial dysfunction, activation of caspases (the enzymes that execute apoptosis), and disruption of calcium homeostasis. The peptide also induces an inflammatory response in glial cells, leading to the release of pro-inflammatory cytokines. Its activity is often quantified by measuring cell viability (e.g., via MTT assay), ROS production, or apoptotic markers like caspase-3 activity. The Aβ(25-35) fragment is highly effective in inducing these effects, making it a preferred model for studying the molecular mechanisms of Alzheimer's disease and for screening neuroprotective compounds.

Alzheimer's disease models can be created using animal models with β-Amyloid (25–35).
In vivo, administration of Amyloid beta-peptide(25-35) to animal models, typically rodents, reproduces key features of Alzheimer's disease pathology. Intracerebroventricular (ICV) injection of the peptide is a common method to induce cognitive deficits and neurodegeneration. This model is used to study the neurotoxic, inflammatory, and oxidative stress effects of the amyloid peptide in a living system. The peptide causes impairment in learning and memory, as assessed by behavioral tests like the Morris water maze. It also triggers neuroinflammation, glial activation, and oxidative stress in the brain. This model is widely used for evaluating the in vivo efficacy of potential therapeutic compounds. The peptide's ability to induce these pathological changes in a relatively short time frame makes it a practical and widely used tool for Alzheimer's disease research.

In vitro enzyme or receptor binding assays for Amyloid beta-peptide(25-35) are not typically performed to measure its affinity for a single target, as its mechanism is multi-faceted. However, its effects can be studied in various biochemical assays. For example, its ability to induce mitochondrial dysfunction can be assessed by isolating brain mitochondria and measuring parameters like mitochondrial membrane potential, reactive oxygen species (ROS) production, and cytochrome c release. The peptide's direct interaction with membranes can be studied using liposome-based assays to understand its membrane-disrupting properties. Its ability to inhibit sodium/calcium exchange can be measured using plasma membrane vesicles. These cell-free systems allow researchers to dissect the specific biochemical pathways through which Aβ(25-35) exerts its toxic effects, providing insights into the molecular mechanisms of neurodegeneration.

In vitro cell-based assays are the most common method for studying the neurotoxic activity of Amyloid beta-peptide(25-35). In a typical experiment, neuronal cell lines (e.g., SH-SY5Y, PC12) or primary cortical neurons are cultured and treated with varying concentrations of Aβ(25-35), typically ranging from 1 to 50 µM, for 24 to 72 hours. The peptide is often pre-aggregated by incubating it in solution at 37°C for several days to form the toxic fibrillar structures. After treatment, cell viability is measured using colorimetric assays like MTT or CCK-8, which assess mitochondrial function. Apoptosis is quantified by measuring caspase-3/7 activity or by using fluorescent dyes like Annexin V. Oxidative stress is evaluated by measuring intracellular ROS levels using fluorescent probes like DCFH-DA. These assays provide a robust and quantifiable measure of the peptide's neurotoxicity and are essential for screening neuroprotective compounds.

In vivo animal studies are a critical component of research using Amyloid beta-peptide(25-35). A common protocol involves the intracerebroventricular (ICV) injection of the peptide into the brains of rodents (mice or rats). The peptide is typically dissolved in sterile saline or artificial cerebrospinal fluid and aggregated before injection. A single dose or multiple doses over several days are administered. Following the injection, animals are allowed to recover and then subjected to behavioral tests to assess cognitive function, such as the Morris water maze for spatial learning and memory, or the passive avoidance test for fear memory. After the behavioral testing, animals are sacrificed, and brain tissues are collected for biochemical and histological analyses. These analyses include measuring markers of oxidative stress, neuroinflammation, and apoptosis, as well as performing histopathological staining to assess neuronal loss. This model is instrumental in studying the in vivo mechanisms of Aβ toxicity and evaluating the therapeutic potential of drug candidates.

The pharmacokinetic properties of Amyloid beta-peptide(25-35) are characteristic of a peptide. When administered directly into the cerebrospinal fluid via ICV injection, the peptide bypasses the blood-brain barrier and is distributed within the central nervous system. The peptide is susceptible to proteolytic degradation by endogenous peptidases, which limits its half-life in vivo. Its clearance from the brain occurs via enzymatic breakdown and bulk flow of cerebrospinal fluid. The peptide has very poor oral bioavailability and does not cross the blood-brain barrier effectively when administered systemically, which is why direct central administration is the preferred route in research settings. For experimental purposes, the peptide is typically dissolved in a suitable solvent such as sterile water, saline, or DMSO, and then diluted in aqueous buffers. It should be stored as a lyophilized powder at -20°C to maintain its stability.

The toxicological profile of Amyloid beta-peptide(25-35) is defined by its neurotoxicity. In cell culture, it is directly toxic to neurons, causing cell death through apoptosis and necrosis. In vivo, when injected into the brain, it induces a range of pathological effects including neuronal loss, synaptic dysfunction, glial activation, and cognitive impairment. These effects are the basis for its use as a disease model. As a research tool, it is not intended for therapeutic use in humans. For laboratory safety, standard precautions for handling peptides and neurotoxic compounds should be followed. This includes wearing gloves and safety goggles to avoid skin contact and inhalation of the lyophilized powder. The peptide is for research use only.

[1]. Solution structure of amyloid beta-peptide (25-35) in different media. J Med Chem. 2004 Aug 12;47(17):4231-8.

[2]. Abeta(31-35) and Abeta(25-35) fragments of amyloid beta-protein induce cellular death throughapoptotic signals: Role of the redox state of methionine-35. FEBS Lett. 2005 May 23;579(13):2913-8.

[3]. Cognitive improvement of compound danshen in an Aβ25-35 peptide-induced rat model of Alzheimer's disease. BMC Complement Altern Med. 2015 Oct 23;15:382.

[4]. Potent anti-angiogenic motifs within the Alzheimer beta-amyloid peptide. Amyloid. 2008;15(1):5-19.

[5]. Ropren® is a polyprenol preparation from coniferous plants that ameliorates cognitive deficiency in a rat model of beta-amyloid peptide-(25–35)-induced amnesia. Phytomedicine. 2012 Mar 15;19(5):451-6.

Amyloid beta-peptide(25-35) is a synthetic peptide representing a key fragment of the amyloid-beta protein, which is central to the pathology of Alzheimer's disease. Its sequence (GSNKGAIIGLM) is highly conserved and is the minimal fragment required to replicate the neurotrophic and neurotoxic effects of the full-length peptide. This makes it an indispensable tool for Alzheimer's disease research, allowing scientists to study the mechanisms of neurodegeneration in simplified models. The peptide is available from numerous chemical suppliers and is used in a wide range of studies, from basic mechanistic research to the screening of potential therapeutic compounds. It is important to note that the peptide's activity is highly dependent on its aggregation state, and protocols for preparing the peptide in its toxic oligomeric or fibrillar form are critical for experimental consistency. The peptide is intended for research use only and is not for human therapeutic or diagnostic use.

C45H81N13O14S

1060.2683

1059.57

131602-53-4

3407255

White to off-white solid powder

1.249g/cm3

1517.336ºC at 760 mmHg

871.453ºC

0mmHg at 25°C

1.544

1.058

15

17

37

73

1880

0

WIHBNMPFWRHGDF-UHFFFAOYSA-N

InChI=1S/C45H81N13O14S/c1-9-24(5)36(43(69)50-21-35(63)52-29(17-23(3)4)40(66)55-28(45(71)72)14-16-73-8)58-44(70)37(25(6)10-2)57-38(64)26(7)51-34(62)20-49-39(65)27(13-11-12-15-46)54-41(67)30(18-32(48)60)56-42(68)31(22-59)53-33(61)19-47/h23-31,36-37,59H,9-22,46-47H2,1-8H3,(H2,48,60)(H,49,65)(H,50,69)(H,51,62)(H,52,63)(H,53,61)(H,54,67)(H,55,66)(H,56,68)(H,57,64)(H,58,70)(H,71,72)

2-[[2-[[2-[[2-[[2-[2-[[2-[[6-amino-2-[[4-amino-2-[[2-[(2-aminoacetyl)amino]-3-hydroxypropanoyl]amino]-4-oxobutanoyl]amino]hexanoyl]amino]acetyl]amino]propanoylamino]-3-methylpentanoyl]amino]-3-methylpentanoyl]amino]acetyl]amino]-4-methylpentanoyl]amino]-4-methylsulfanylbutanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product is not stable in solution, please use freshly prepared working solution for optimal results.  (2). Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ≥ 3.33 mg/mL (~3.14 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (2.36 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)