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Amyloid β protein

Amyloid beta ( or Abeta) denotes peptides of 36–43 amino acids that are the main component of the amyloid plaques found in the brains of people with Alzheimer's disease. The peptides derive from the amyloid precursor protein (APP), which is cleaved by beta secretase and gamma secretase to yield Aβ. Aβ molecules can aggregate to form flexible soluble oligomers which may exist in several forms. It is now believed that certain misfolded oligomers (known as "seeds") can induce other Aβ molecules to also take the misfolded oligomeric form, leading to a chain reaction akin to a prion infection. The oligomers are toxic to nerve cells. The other protein implicated in Alzheimer's disease, tau protein, also forms such prion-like misfolded oligomers, and there is some evidence that misfolded Aβ can induce tau to misfold.

The normal function of Aβ is not well understood. Though some animal studies have shown that the absence of Aβ does not lead to any obvious loss of physiological function, several potential activities have been discovered for Aβ, including activation of kinase enzymes, protection against oxidative stress, regulation of cholesterol transport, functioning as a transcription factor, and anti-microbial activity (potentially associated with Aβ's pro-inflammatory activity).

The glymphatic system clears metabolic waste from the mammalian brain, and in particular amyloid beta. Indeed, a number of proteases have been implicated by both genetic and biochemical studies as being responsible for the recognition and degradation of amyloid beta; these include insulin degrading enzyme.and presequence protease. The rate of removal is significantly increased during sleep. However, the significance of the lymphatic system in Aβ clearance in Alzheimer's disease is unknown.

Targets for  Amyloid β protein

Products for  Amyloid β protein

  1. Cat.No. Product Name Information
  2. GC37984 β-Amyloid (1-42), rat β-Amyloid (1-42), rat  Chemical Structure
  3. GC61394 β-Amyloid (1-42), rat TFA β-Amyloid (1-42), rat TFA  Chemical Structure
  4. GC61988 β-amyloid (12-28) (TFA) β-amyloid (12-28) (TFA)  Chemical Structure
  5. GC39466 β-Amyloid 15-21 β-Amyloid 15-21  Chemical Structure
  6. GC37991 β-Amyloid 15-21 β-Amyloid 15-21  Chemical Structure
  7. GC34242 β-Amyloid (1-42), rat TFA β-Amyloid (1-42), rat TFA  Chemical Structure
  8. GC31146 β-Amyloid (10-35), amide β-Amyloid (10-35), amide  Chemical Structure
  9. GC31129 β-Amyloid 1-16 (Amyloid β-Protein (1-16)) β-Amyloid 1-16 (Amyloid β-Protein (1-16))  Chemical Structure
  10. GC31171 β-Amyloid 1-28 (Amyloid β-Protein (1-28)) β-Amyloid 1-28 (Amyloid β-Protein (1-28))  Chemical Structure
  11. GC30325 β-Amyloid 22-35 (Amyloid β-Protein (22-35)) β-Amyloid 22-35 (Amyloid β-Protein (22-35))  Chemical Structure
  12. GC31137 β-Amyloid 29-40 (Amyloid beta-protein(29-40)) β-Amyloid 29-40 (Amyloid beta-protein(29-40))  Chemical Structure
  13. GC31179 β-Amyloid 31-35 β-Amyloid 31-35  Chemical Structure
  14. GA20024 (7-Diethylaminocoumarin-3-yl)carbonyl-Amyloid β-Protein (1-40) Amyloid β-protein (1-40) that is N-terminally modified with the fluorescent dye (7-diethylaminocoumarin-3-yl)carbonyl (DAC or DEAC). This derivative can be utilized to assess the binding properties of amyloid β-protein (1-40) for various membranes since it behaves very similar to the native peptide. In aqueous environments the fluorophore is almost non-fluorescent whereas binding to membranes results in an increase in fluorescence intensity (Λex = 430 nm, Λem = 470 nm). Increases in the GM1 ganglioside and cholesterol content in the lipid bilayers facilitated the binding of this peptide. For phosphatidylcholine and phosphatidylserine no affinity was observed. (7-Diethylaminocoumarin-3-yl)carbonyl-Amyloid β-Protein (1-40)  Chemical Structure
  15. GA20029 (Arg¹³)-Amyloid β-Protein (1-40) H13R, a mutation in the metal-binding region of Abeta reduces its copper-mediated toxicity. The native rodent sequence containing an arginine at this position is more tolerant to metals than the human amyloid peptide. (Arg¹³)-Amyloid β-Protein (1-40)  Chemical Structure
  16. GA20030 (Arg⁶)-Amyloid β-Protein (1-40) The English (H6R) mutation of β-amyloid peptides accelerates fibrillation without increasing protofibril formation. Ono et al. showed that the English and Tottori mutations alter Abeta assembly at its earliest stages, monomer folding and oligomerization, and produce oligomers that are more toxic to cultured neuronal cells than are wild type oligomers. The exchange of His? by Arg influences the structure of the Cu(II) complex formed by Aβ peptides. (Arg⁶)-Amyloid β-Protein (1-40)  Chemical Structure
  17. GA20038 (Asn²³)-Amyloid β-Protein (1-40) The Iowa (D23N) mutant of Aβ 40 considerably more rapidly assembles in solution to form fibrils than the WT Aβ sequence. These fibrils also show a different structure, which could be responsible for their increased toxicity. (Asn²³)-Amyloid β-Protein (1-40)  Chemical Structure
  18. GA20039 (Asn⁶⁷⁰,Leu⁶⁷¹)-Amyloid β/A4 Protein Precursor₇₇₀ (667-675) SEVNLDAEF corresponds to the mutant junctional sequence of the amyloid precursor protein (APP) found in a Swedish family with early-onset Alzheimer's disease, therefore referred to as the 'Swedish' mutation (K670N/M671L). The peptide has been used for assaying cleavage at leucine-aspartate by cathepsin G and chymotrypsin, whereas neither cathepsin B, D nor L generated any products. (Asn⁶⁷⁰,Leu⁶⁷¹)-Amyloid β/A4 Protein Precursor₇₇₀ (667-675)  Chemical Structure
  19. GA20040 (Asn⁶⁷⁰,Leu⁶⁷¹)-Amyloid β/A4 Protein Precursor₇₇₀ (667-676) This peptide substrate corresponds to the 'Swedish' Lys-Met/Asn-Leu (K670N/M671L) mutation of the amyloid precursor protein (APP) β-secretase cleavage site. It has been used for assaying β-secretase activity. (Asn⁶⁷⁰,Leu⁶⁷¹)-Amyloid β/A4 Protein Precursor₇₇₀ (667-676)  Chemical Structure
  20. GA20041 (Asn⁶⁷⁰,Sta⁶⁷¹,Val⁶⁷²)-Amyloid β/A4 Protein Precursor₇₇₀ (662-675) Amyloid precursor protein (APP) β-secretase from human brain cleaves full-length APP at the amino terminus of the amyloid β-protein (Aβ) sequence, thus leading to the generation and extracellular release of β-cleaved soluble APP and a corresponding cell-associated carboxy-terminal fragment. The subsequent cleavage of the C-terminal fragment by γ-secretase(s) leads to the formation of Aβ. This new peptide represents a potent substrate analog inhibitor of APP β-secretase with IC?? = 30 nM. (Asn⁶⁷⁰,Sta⁶⁷¹,Val⁶⁷²)-Amyloid β/A4 Protein Precursor₇₇₀ (662-675)  Chemical Structure
  21. GA20042 (Asn⁷)-Amyloid β-Protein (1-40) The Tottori (D7N) mutation of β-amyloid peptides accelerates fibrillation without increasing protofibril formation. Ono et al. showed that the English and Tottori mutations alter Abeta assembly at its earliest stages, monomer folding and oligomerization, and produce oligomers that are more toxic to cultured neuronal cells than are wild type oligomers. (Asn⁷)-Amyloid β-Protein (1-40)  Chemical Structure
  22. GA20045 (Asp³⁷)-Amyloid β-Protein (1-42) The G37D mutant does not show the aggregation behavior of WT Abeta42 nor its neurotoxicity. (Asp³⁷)-Amyloid β-Protein (1-42)  Chemical Structure
  23. GA20053 (Cys²⁶)-Amyloid β-Protein (1-40) Aβ40 S26C has been used for generating the covalently linked Aβ40 homodimer. Dimerization can be easily reverted by reducing the soluble dimer with thiols as β-mercaptoethanol. Aβ40 S26C is perfectly suited for labeling with fluorescent tags (Cys²⁶)-Amyloid β-Protein (1-40)  Chemical Structure
  24. GA20052 (Cys²⁶)-Amyloid β-Protein (1-40) (Dimer) Dimer of H-7402. (Cys²⁶)-Amyloid β-Protein (1-40) (Dimer)  Chemical Structure
  25. GA20050 (Cys⁰)-Amyloid β-Protein (1-40) Cys-Aβ1-40 can be easily and selectively modified, labeled, coupled to carriers e.g. by maleimide chemistry without affecting the sequences involved in fibril formation. The free mercapto moiety of the peptide adheres to gold surfaces. (Cys⁰)-Amyloid β-Protein (1-40)  Chemical Structure
  26. GA20095 (Des-Glu²²)-Amyloid β-Protein (1-40) The Osaka mutation was the first deletion-type mutation to be identified in APP and Aβ. The Aβ E22delta mutant is more resistant to degradation by two major Aβ-degrading enzymes, neprilysin and insulin-degrading enzyme. Synthetic mutant Aβ showed unusual aggregation properties with enhanced oligomerization but no fibrillization. It also inhibited hippocampal long-term potentiation more efficiently than wild-type Aβ. A transgenic mouse model containing APP with the E693delta mutation has been developed. APP(OSK)-Tg mice exhibit intraneuronal Aβ E22delta oligomers and memory impairment as early as eight months of age. (Des-Glu²²)-Amyloid β-Protein (1-40)  Chemical Structure
  27. GA20096 (Des-Glu²²)-Amyloid β-Protein (1-42) The Osaka (E22delta) mutation of Amyloid β promotes β-sheet transformation, radical production, and synaptotoxicity, but not neurotoxicity. (Des-Glu²²)-Amyloid β-Protein (1-42)  Chemical Structure
  28. GA20182 (Gln²²)-Amyloid β-Protein (1-40) The Dutch mutation (E22Q) of amyloid β-peptide aggregates more readily than the wild-type peptide and the resulting fibrils show increased neurotoxicity. The mutant peptide E22Q induced apoptosis of cerebral endothelial cells at a concentration of 25 μm, whereas WT Aβ 1-40 and the Italian mutant E22K (H-6698) showed no effect. (Gln²²)-Amyloid β-Protein (1-40)  Chemical Structure
  29. GA20183 (Gln²²)-Amyloid β-Protein (1-42) The Dutch mutation (E22Q) aggregates more readily than the wild-type sequence. The resulting fibrils show increased neurotoxicity. (Gln²²)-Amyloid β-Protein (1-42)  Chemical Structure
  30. GA20184 (Gln²²,Asn²³)-Amyloid β-Protein (1-40) Transgenic mice expressing the vasculotropic Dutch/Iowa (E693Q/D694N) mutant human Aβ precursor protein in brain (Tg-SwDI) accumulate abundant cerebral microvascular fibrillar amyloid deposits and exhibit robust neuroinflammation. In vitro, the doubly mutated Aβ peptides showed an increased propensity to fibrillation and pathogenicity compared to the Dutch and Iowa single mutants. (Gln²²,Asn²³)-Amyloid β-Protein (1-40)  Chemical Structure
  31. GA20181 (Gln¹¹)-Amyloid β-Protein (1-28) (Gln¹¹)-Amyloid β-Protein (1-28)  Chemical Structure
  32. GA20186 (Gln⁹)-Amyloid β-Protein (1-40) (Gln⁹)-Amyloid β-Protein (1-40)  Chemical Structure
  33. GA20199 (Gly²²)-Amyloid β-Protein (1-40) The highly neurotoxic arctic mutant (E22G) of Aβ has been used to study the mechanisms underlying the formation of soluble and insoluble β-amyloid aggregates. As the wild-type Aβ, the arctic mutant preferably assembles in the presence of GM1 ganglioside. (Gly²²)-Amyloid β-Protein (1-40)  Chemical Structure
  34. GA20200 (Gly²²)-Amyloid β-Protein (1-42) The arctic mutant of amyloid β peptide 1-42, in which Glu²² is substituted by Gly, is distinctly more amyloidogenic than the wild-type Aβ 1-42. (Gly²²)-Amyloid β-Protein (1-42)  Chemical Structure
  35. GA20197 (Gly²¹)-Amyloid β-Protein (1-40) Contrary to β-amyloid peptides mutated at position 22 (Dutch, Italian, Arctic mutants) the Flemish mutation (A21G) shows a decreased tendency to aggregate and a reduced neurotoxicity. In the studies of Betts and Tsubuki, A21G was degraded significantly more slowly by neprilysin than the wild-type Aβ 1-40 and the E22 mutants. The relative resistance to proteolytic degradation may account for the pathogenicity of the Aβ mutant. (Gly²¹)-Amyloid β-Protein (1-40)  Chemical Structure
  36. GA20198 (Gly²¹)-Amyloid β-Protein (1-42) The Flemish mutation (A21G) shows a decreased tendency to aggregate and a reduced neurotoxicity. A21G is pathogenic as it is degraded significantly more slowly by neprilysin than WT Abeta42. (Gly²¹)-Amyloid β-Protein (1-42)  Chemical Structure
  37. GA20201 (Gly²⁸,Cys³⁰)-Amyloid β-Protein (1-30) amide (Gly²⁸,Cys³⁰)-Amyloid β-Protein (1-30) amide  Chemical Structure
  38. GA20244 (Lys²²)-Amyloid β-Protein (1-40) The Italian mutation of β-amyloid 1-40 (E22K) aggregates more rapidly than the wild-type sequence 1-40. It showed increased neurotoxicity, which (according to a solid-phase NMR-study of Masuda et al.) may be due to the salt bridge formed between Lys²² and Asp²³ in the minor conformer. As the Arctic, Flemish, and Dutch mutants, the Italian mutant is degraded considerably more slowly than wild-type Aβ by neprilysin. (Lys²²)-Amyloid β-Protein (1-40)  Chemical Structure
  39. GA20245 (Lys²²)-Amyloid β-Protein (1-42) The Italian mutation (E22K) aggregates more rapidly than the wild-type sequence. (Lys²²)-Amyloid β-Protein (1-42)  Chemical Structure
  40. GA20242 (Lys¹⁵)-Amyloid β-Protein (15-21) KKLVFFA contains the KLVFF sequence, which is the minimum sequence binding the full-length amyloid β-protein. It showed improved water solubility compared with KLVFF (H-3682). It can be used as a labeled probe for screening defined sequences in the full-length amyloid β-protein. (Lys¹⁵)-Amyloid β-Protein (15-21)  Chemical Structure
  41. GA20251 (Met(O)³⁵)-Amyloid β-Protein (1-40) Oxidation of Met35 attenuates the formation of Aβ40 oligomers. (Met(O)³⁵)-Amyloid β-Protein (1-40)  Chemical Structure
  42. GA20252 (Met(O)³⁵)-Amyloid β-Protein (1-42) (Met(O)³?)-Amyloid β-protein (1-42) (H-5888), in contrast to Aβ 1-42 (H-1368), has been shown to be non-toxic to 9-11 day-old rat embryonic hippocampal neuronal cultures and not to produce any protein oxidation. It has also been demonstrated that fibril formation is not affected by Met(O)³?. For the Nle analog see H-7308. (Met(O)³⁵)-Amyloid β-Protein (1-42)  Chemical Structure
  43. GA20253 (Met(O)³⁵)-Amyloid β-Protein (25-35) Sulfoxide of Aβ 25-35. (Met(O)³⁵)-Amyloid β-Protein (25-35)  Chemical Structure
  44. GA20254 (Met(O₂)³⁵)-Amyloid β-Protein (1-42) Maiti et al. could show that, in contrast to the sulfoxide of Aβ (1-42), the sulfone was as toxic and aggregated as fast as wild-type Aβ (1-42). (Met(O₂)³⁵)-Amyloid β-Protein (1-42)  Chemical Structure
  45. GA20259 (Nle³⁵)-Amyloid β-Protein (1-40) The reactive thioether of Met³? is crucial for the activity of Aβ 1-40 and Aβ 1-42. Due to the replacement of Met by inert Nle, M35Nle Aβ 1-40 was no longer toxic to cultured hippocampal neurons and had little effect on the level of protein carbonyl residues. The Nle peptide showed the same propensity to aggregate, whereas sulfoxide formation hindered the required conformational transition from random coil to β-sheet. (Nle³⁵)-Amyloid β-Protein (1-40)  Chemical Structure
  46. GA20260 (Nle³⁵)-Amyloid β-Protein (1-42) The thioether of Met³? plays a critical role in the oxidative stress induced by Aβ 1-42 and its neurotoxicity. The norleucine analog Aβ 1-42 M35Nle forms fibrils morphologically indistinguishable from the ones of the native sequence though lacking their neurotoxicity. (Nle³⁵)-Amyloid β-Protein (1-42)  Chemical Structure
  47. GA20283 (Pyr³)-Amyloid β-Protein (3-40) The pyroglutamate-modified amyloid-β peptides derived from Aβ40 (H-7422) and Aβ42 (H-4796) have gained considerable attention as potential key participants in the pathology of Alzheimer's disease (AD) due to their abundance in AD brain, high aggregation propensity, stability, and cellular toxicity. Aβ40 and 42 can be N-terminally truncated by action of cathepsin B. The cyclization of Glu³ is catalyzed by glutaminyl cyclase. Hence, inhibition of these enzymes could be a therapeutic approach to AD. (Pyr³)-Amyloid β-Protein (3-40)  Chemical Structure
  48. GA20285 (Pyr³)-Amyloid β-Protein (3-42) (Pyr³)-Amyloid β-Protein (3-42)  Chemical Structure
  49. GA20284 (Pyr³)-Amyloid β-Protein (3-42) (Pyr³)-Amyloid β-Protein (3-42) was found to be the predominant amyloid β-peptide structure deposited in human brain of Alzheimer's disease and Down's syndrome patients. Therefore, (Pyr³)-Aβ (3-42) is suggested to accumulate in the brain and to trigger the formation of insoluble amyloid β-peptide deposits. Nussbaum et al. studies the Prion-like behaviour and tau-dependent cytotoxicity of the truncated Aβ sequence. (Pyr³)-Amyloid β-Protein (3-42)  Chemical Structure
  50. GA20282 (Pyr¹¹)-Amyloid β-Protein (11-40) pEVHHQKLVFFAEDVGSNKGAIIGLMVGGVV, the N-terminally truncated isoform of the amyloid β-protein (Aβ) beginning with a pyroglutamate (Pyr) residue at position 11 was used in experiments studying the generality of fibrillogenesis-related helix formation. Comparing the fibrillogenesis kinetics of many of the most important clinically relevant amyloid β-protein alloforms it could be observed that among these peptides (Pyr¹¹)-amyloid β-protein (11-40) exhibited the greatest retardation of fibrillization rate. (Pyr¹¹)-Amyloid β-Protein (11-40)  Chemical Structure
  51. GA20309 (Thr²)-Amyloid β-Protein (1-42) A mutation very close to the β-secretase cleavage site of APP. The Icelandic mutation A2T of Aβ42 turned out to be less pathogenic than the native sequence. The precursor APP A673T was the first APP variant discovered in humans reducing the risk of Alzheimer's disease. A2T as well affects γ-secretase cleavage, the mutant was an inefficient substrate in a cell-based assay of the enzyme. (Thr²)-Amyloid β-Protein (1-42)  Chemical Structure
  52. GA20339 (Val²)-Amyloid β-Protein (1-42) A mutation very close to the β-secretase cleavage site of APP (A673V). Contrary to the protective Icelandic mutation A2T, the recessive A2V mutation may increase the risk of Alzheimer's disease. Cantu et al. observed that APP A673V is associated with the early onset of AD-type dementia in homozygous individuals, whereas it has a protective effect in the heterozygous state. (Val²)-Amyloid β-Protein (1-42)  Chemical Structure
  53. GA20340 (Val²)-Amyloid β-Protein (1-6) (Val²)-Amyloid β-Protein (1-6)  Chemical Structure
  54. GA20341 (Val³⁴)-Amyloid β-Protein (1-40) Cerebral amyloid angiopathy (CAA) is a common finding in Alzheimer's disease in which amyloid-Aβ vascular deposits are featured in >80% of the cases. Mutations in the positions 21-23 (e.g. Dutch mutation E22Q) are primarily associated with CAA, although they manifest with strikingly different clinical phenotypes: cerebral hemorrhage or dementia. The Piedmont L34V Aβ mutant, located outside this hot spot, shows a similar hemorrhagic phenotype, albeit less aggressive than the widely studied Dutch variant. (Val³⁴)-Amyloid β-Protein (1-40)  Chemical Structure
  55. GA20433 5-FAM-Amyloid β-Protein (1-40) 5-FAM-Amyloid β-Protein (1-40)  Chemical Structure
  56. GA20435 5-FAM-Amyloid β-Protein (1-42) 5-FAM-Amyloid β-Protein (1-42)  Chemical Structure
  57. GA20434 5-FAM-Amyloid β-Protein (1-42) (scrambled) Fluorescent dye-labeled inactive control for H-1368, H-6466, H-8146. 5-FAM-Amyloid β-Protein (1-42) (scrambled)  Chemical Structure
  58. GC42505 5-FAM-Amyloid-β (1-28) Peptide (human) (trifluoroacetate salt) 5-FAM-Amyloid-β (1-28) peptide is a fluorescently labeled peptide. 5-FAM-Amyloid-β (1-28) Peptide (human) (trifluoroacetate salt)  Chemical Structure
  59. GC40130 5-FAM-Amyloid-β (1-42) Peptide (human) (trifluoroacetate salt) 5-FAM-Amyloid-β (1-42) peptide is a fluorescently labeled amyloid-β peptide. 5-FAM-Amyloid-β (1-42) Peptide (human) (trifluoroacetate salt)  Chemical Structure
  60. GA20440 5-TAMRA-Amyloid β-Protein (1-40) Anderson and Webb could verify using transmission electron microscopy that N-terminal labeling of Aβ40 with TAMRA and other fluorescent dyes does not prevent the formation of protofibrils and amyloid fibrils of various widths. 5-TAMRA-Amyloid β-Protein (1-40)  Chemical Structure
  61. GA20441 5-TAMRA-Amyloid β-Protein (1-42) 5-TAMRA-Amyloid β-Protein (1-42)  Chemical Structure
  62. GA20448 Abz-(Asn⁶⁷⁰,Leu⁶⁷¹)-Amyloid β/A4 Protein Precursor₇₇₀ (669-674)-EDDnp Intramolecularly quenched fluorescent substrate containing the ortho-aminobenzoyl (Abz) / N-(2,4-dinitrophenyl)ethylenediamine (EDDnp) groups as the donor / acceptor pair. It corresponds to the Swedish-mutated (JMV2236) β-amyloid precursor protein (βAPP) sequence targeted by β-secretase BACE (β-site APP-cleaving activity). This FRET substrate is more selectively cleaved by BACE1 and BACE2 than by cathepsin D, a disintegrin and metalloprotease 10 (ADAM10), tumor necrosis α-converting enzyme (TACE), presenilin-1 (PS1), or presenilin-2 (PS2). Abz-(Asn⁶⁷⁰,Leu⁶⁷¹)-Amyloid β/A4 Protein Precursor₇₇₀ (669-674)-EDDnp  Chemical Structure
  63. GA20452 Abz-Amyloid β/A4 Protein Precursor₇₇₀ (669-674)-EDDnp Intramolecularly quenched fluorescent substrate containing the ortho-aminobenzoyl (Abz) / N-(2,4-dinitrophenyl)ethylenediamine (EDDnp) groups as the donor / acceptor pair. It mimicks the wild-type (JMV2235) β-amyloid precursor protein (βAPP) sequence targeted by β-secretase BACE (β-site APP-cleaving activity). This FRET substrate is cleaved by BACE1, BACE2, and cathepsin D. Abz-Amyloid β/A4 Protein Precursor₇₇₀ (669-674)-EDDnp  Chemical Structure
  64. GA20453 Abz-Amyloid β/A4 Protein Precursor₇₇₀ (708-715)-Lys(Dnp)-D-Arg-D-Arg-D-Arg amide A sensitive fluorogenic (FRET) substrate developed for the analysis of γ-secretase from post mortem non-Alzheimer's and Alzheimer's disease human brain isolates. Abz-Amyloid β/A4 Protein Precursor₇₇₀ (708-715)-Lys(Dnp)-D-Arg-D-Arg-D-Arg amide  Chemical Structure
  65. GA20525 Acetyl-(N-Me-Leu¹⁷,N-Me-Phe¹⁹)-Amyloid β-Protein (16-20) amide Membrane-permeable inhibitor of Aβ (1-40) fibrillogenesis. Acetyl-(N-Me-Leu¹⁷,N-Me-Phe¹⁹)-Amyloid β-Protein (16-20) amide  Chemical Structure
  66. GA20526 Acetyl-(Pro¹⁸,Asp²¹)-Amyloid β-Protein (17-21) amide The pentapeptide Ac-LPFFD-NH? (iAβ5p) is an analog of product H-4876 with small chemical modifications which enhance its stability against proteolytic degradation. iAβ5p acts as a β-sheet breaker peptide and crosses the blood-brain barrier at a higher rate than most proteins and peptides known to be selectively taken up by the brain so that it is assumed that the peptide is being specifically transported to the brain. A significant increase in neuronal survival and decrease in brain inflammation associated with the reduction of amyloid plaques in two different transgenic Alzheimer`s disease (AD) models is additionally reported for iAβ5p. Acetyl-(Pro¹⁸,Asp²¹)-Amyloid β-Protein (17-21) amide  Chemical Structure
  67. GA20535 Acetyl-Amyloid β-Protein (1-6) amide Experiments using sub-peptides of Aβ42 revealed that the epitope identified by the antibody A8, as described by Ying and coworkers, lies within the 1-6 region of Aβ. The antibody displays high affinity for soluble Aβ42 oligomers in the molecular weight range of 16.5-25 kDa, and detected target antigen in brain sections from senescence-accelerated SAMP 8 mice. Amidated or acetylated and amidated forms of the sequence were used for example for quantitative structure retention relationships (QSRR) experiments. The latter could allow prediction of reversed-phase high-performance liquid chromatography (HPLC) retention of peptides, as reported by Kaliszan and coworkers. Acetyl-Amyloid β-Protein (1-6) amide  Chemical Structure
  68. GA20534 Acetyl-Amyloid β-Protein (15-20) amide Incubation of Ac-QKLVFF-NH? with the amyloid β-protein (1-40) inhibited polymerization of the amyloid β-protein (1-40) into amyloid fibrils. The peptide is thought to block the polymerization sites. Acetyl-Amyloid β-Protein (15-20) amide  Chemical Structure
  69. GA20533 Acetyl-Amyloid β/A4 Protein Precursor₇₇₀ (96-110) (cyclized) This cyclized peptide which is homologous to the heparin-binding domain of APP, binds strongly to heparin and inhibits binding of ¹²?I-labeled APP to heparin (IC??= 10??M). The peptide blocks the heparan sulfate proteoglycan-dependent stimulatory effect of APP on neurite outgrowth. Acetyl-Amyloid β/A4 Protein Precursor₇₇₀ (96-110) (cyclized)  Chemical Structure
  70. GC35334 Amyloid β Peptide (42-1)(human) Amyloid β Peptide (42-1)(human)  Chemical Structure
  71. GC35335 Amyloid β-peptide (1-40) rat Amyloid β-peptide (1-40) rat  Chemical Structure
  72. GA20721 Amyloid β-Protein (1-12) Amyloid β-Protein (1-12)  Chemical Structure
  73. GA20722 Amyloid β-Protein (1-14) The N-terminal Aβ fragments Aβ1-14, Aβ1-15 (H-6368), and Aβ1-16 (H-2958) are elevated in cell media and in CSF in response to γ-secretase inhibitor treatment. The presence of these small peptides is consistent with a catabolic amyloid precursor protein cleavage pathway by β- followed by α-secretase. It has been shown that Aβ1-14, Aβ1-15, and Aβ1-16 increase dose-dependently in response to γ-secretase inhibitor treatment while Aβ1-42 levels are unchanged. Amyloid β-Protein (1-14)  Chemical Structure
  74. GA20724 Amyloid β-Protein (1-24) Amyloid β-Protein (1-24)  Chemical Structure
  75. GA20725 Amyloid β-Protein (1-37) Amyloid β-Protein (1-37)  Chemical Structure
  76. GA20726 Amyloid β-Protein (1-38) Like Aβ (25-35) (H-1192), the Aβ fragment (1-38) destabilizes calcium homeostasis and renders human cortical neurones vulnerable to environmental insults. Amyloid β-Protein (1-38)  Chemical Structure
  77. GA20727 Amyloid β-Protein (1-39) Small quantities of Aβ37, 38 and 39 can be detected in CSF together with Aβ40, the most abundant Aβ homolog, Aβ42, and N-terminally truncated amyloid peptides. The relative amounts depend on the variant of Alzheimer's disease. The C-terminally truncated amyloid peptides are also found in amyloid plaques. Amyloid β-Protein (1-39)  Chemical Structure
  78. GA20728 Amyloid β-Protein (1-40) (scrambled) Amyloid β-Protein (1-40) (scrambled)  Chemical Structure
  79. GA20729 Amyloid β-Protein (1-40) amide Amyloid β-Protein (1-40) amide  Chemical Structure
  80. GA20735 Amyloid β-Protein (1-42) For a detailed description of Aβ 1-42, please see product H-1368. For the preparation of Aβ for experimental use, Fezoui et al. (2000) found that solvation of synthetic peptide with sodium hydroxide (Aβ.NaOH) followed by lyophilization, produced stocks with superior solubility and fibrillogenesis characteristics. Solubilization of the pretreated material with neutral buffers resulted in a pH transition from ≈10.5 to neutral, avoiding the isoelectric point of Aβ (pI≈5.5), at which Aβ precipitation and aggregation propensity are maximal. Amyloid β-Protein (1-42)  Chemical Structure
  81. GA20734 Amyloid β-Protein (1-42) Amyloid β-Protein (1-42)  Chemical Structure
  82. GA20733 Amyloid β-Protein (1-42)

    Compared to the inner salt, the HCl salt of Aβ42 aggregates more readily at pH 7.4.

    Amyloid β-Protein (1-42)  Chemical Structure
  83. GA20732 Amyloid β-Protein (1-42) 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 H-1368 corresponds to the human, bovine, canine, feline, ovine, guinea pig, and rabbit Aβ42 peptide. 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. Amyloid β-Protein (1-42)  Chemical Structure
  84. GA20730 Amyloid β-Protein (1-42) (HFIP-treated) H-7442 was obtained by dissolving Amyloid β-Protein (1-42) (H-1368) in HFIP, aliquoting, and removing the solvent as described in the literature. Amyloid β-Protein (1-42) (HFIP-treated)  Chemical Structure
  85. GA20731 Amyloid β-Protein (1-42) (scrambled) Amyloid β-Protein (1-42) (scrambled)  Chemical Structure
  86. GA20736 Amyloid β-Protein (1-43) The amyloid β-protein is a 39- to 43-amino acid polypeptide that is the primary constituent of senile plaques and cerebrovascular deposits in Alzheimer's disease and Down's syndrome. Additionally it acts as an inhibitor of the ubiquitin-dependent protein degradation in vitro. Amyloid β-Protein (1-43)  Chemical Structure
  87. GA20737 Amyloid β-Protein (1-46) Precursor of the secreted amyloid β-protein (1-40) and (1-42). The identification of amyloid-β-protein (1-46) led to the identification of a zeta-cleavage site between the known γ- and ε-cleavage sites within the transmembrane domain of amyloid-β precursor protein (APP). Amyloid β-Protein (1-46)  Chemical Structure
  88. GA20738 Amyloid β-Protein (1-6) Experiments using sub-peptides of Aβ42 revealed that the epitope identified by the antibody A8, as described by Ying and coworkers, lies within the 1-6 region of Aβ. The antibody displays high affinity for soluble Aβ42 oligomers in the molecular weight range of 16.5-25 kDa, and detected target antigen in brain sections from senescence-accelerated SAMP 8 mice. Amyloid β-Protein (1-6)  Chemical Structure
  89. GA20739 Amyloid β-Protein (1-6) amide Experiments using sub-peptides of Aβ42 revealed that the epitope identified by the antibody A8, as described by Ying and coworkers, lies within the 1-6 region of Aβ. The antibody displays high affinity for soluble Aβ42 oligomers in the molecular weight range of 16.5-25 kDa, and detected target antigen in brain sections from senescence-accelerated SAMP 8 mice. Amidated or acetylated and amidated forms of the sequence were used for example for quantitative structure retention relationships (QSRR) experiments. The latter could allow prediction of reversed-phase high-performance liquid chromatography (HPLC) retention of peptides, as reported by Kaliszan and coworkers. Amyloid β-Protein (1-6) amide  Chemical Structure
  90. GA20720 Amyloid β-Protein (10-35) Amyloid β-protein (10-35), YEVHHQKLVFFAEDVGSNKGAIIGLM, was used as a truncated peptide model for the full-length amyloid β-proteins (1-40) and (1-42) in high-resolution structural studies. In contrast to the full-length amyloid β-proteins, amyloid β-protein (10-35) allowed the controlled and reproducible formation of homogeneous fibrils from aqueous solutions of defined pH, ionic strength and soluble peptide concentration necessary for high-resolution structural studies. Amyloid β-Protein (10-35)  Chemical Structure
  91. GA20723 Amyloid β-Protein (11-42) Amyloid β-Protein (11-42)  Chemical Structure
  92. GA20740 Amyloid β-Protein (16-20) KLVFF corresponds to the minimum sequence binding the full-length amyloid β protein. The pentapeptide acts as a β-sheet breaker. Amyloid β-Protein (16-20)  Chemical Structure
  93. GA20741 Amyloid β-Protein (16-22) Self-assembling Aβ sequence. Amyloid β-Protein (16-22)  Chemical Structure
  94. GA20742 Amyloid β-Protein (17-40) Cleavage of APP by alpha- and gamma-secretase (i.e. the non-amyloidogenic pathway) yields p3 peptide, a mix of Aβ 17-40 and Aβ 17-42. p3 is a major constituent of diffuse plaques observed in AD brains and pre-amyloid plaques in people affected by Down syndrome. Amyloid β-Protein (17-40)  Chemical Structure
  95. GA20744 Amyloid β-Protein (2-42) Aβ 2-42 could be a biomarker for differentiating AD from other degenerative dementias, such as frontotemporal dementias (FTD). The peptide promotes phagocytosis by macrophages. Amyloid β-Protein (2-42)  Chemical Structure
  96. GA20743 Amyloid β-Protein (20-29) FAEDVGSNKG. Amyloid β-Protein (20-29)  Chemical Structure
  97. GA20745 Amyloid β-Protein (25-35) amide The amidation of amyloid β-protein (25-35) leads to a product in which the amyloidogenic capacity of amyloid β-protein (25-35) has been strongly reduced, while the neurotoxic activity was found to be independent of the aggregated state of the peptide. Amyloid β-Protein (25-35) amide  Chemical Structure
  98. GA20747 Amyloid β-Protein (3-40) Amyloid β-Protein (3-40)  Chemical Structure
  99. GA20748 Amyloid β-Protein (3-42) The N-terminally truncated Aβ42 may be formed in increased amounts as AD progresses. Aβ 3-42 is the precursor of the Pyr-peptide. (Pyr³)-Aβ 3-42 positive plaques are resistant to age-dependent degradation likely due to their high stability and propensity to aggregate. Amyloid β-Protein (3-42)  Chemical Structure
  100. GA20746 Amyloid β-Protein (33-42) GLMVGGVVIA, a partial sequence of β-amyloid protein which is used for raising antibodies against Aβ 1-42. Li et al. studied the aggregation behavior of this and other Aβ 1-42 C-terminal fragments. Amyloid β-Protein (33-42)  Chemical Structure
  101. GA20749 Amyloid β-Protein (35-25) Reverse sequence of Aβ 25-35, inactive control. Amyloid β-Protein (35-25)  Chemical Structure

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