A Universal Method for Detection of Amyloidogenic Misfolded Proteins

Yam, Alice; Wang, Xuemei; Gao, Carol Man; Connolly, Michael D.; Zuckermann, Ronald N.; Bleu, Thieu; Hall, J. L.; Fedynyshyn, Joseph P.; Allauzen, Sophie; Peretz, David; Salisbury, Cleo M.

doi:10.1021/bi200215j

Cited by 35 publications

(49 citation statements)

References 55 publications

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“…[33][34][35] On the other hand, SPR imaging is ar eal-time, label-free, and high-throughput method. Zhao et al combined the specific recognition of peptoid (ADP3) and the advantages of SPR imaging to detect serum Ab .…”

Section: Surfaceplasmon Resonance Sensorsmentioning

confidence: 99%

Detection of Aβ Monomers and Oligomers: Early Diagnosis of Alzheimer's Disease

Zhou

Liu

Hao

et al. 2016

Chemistry An Asian Journal

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Alzheimer's disease (AD), as the most common progressive neurodegenerative disorder, is pathologically characterized by deposition of extracellular plaque composed of amyloid-β peptide (Aβ). Different assembled states of Aβ have been considered as both important biomarkers and drug targets for the diagnosis and therapy of AD. Recent studies demonstrate that small, diffusible Aβ oligomers formed by aggregation of Aβ monomers are the major toxic agents in AD. Therefore, the development of reliable assays for Aβ (both monomers and oligomers) will be important for the early differential diagnosis of dementia, predicting the progression of AD, as well as monitoring the effectiveness of novel anti-Aβ drugs for AD. In this review, we summarize the recent progress made in the development of techniques for detection of Aβ monomers and oligomers. In particular, the principles governing the design of these sensors are classified and summarized. Moreover, the advantages and disadvantages of the assays are evaluated. This review also discusses the improvements and challenges for application of these assays in the early diagnosis of AD.

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Section: Surfaceplasmon Resonance Sensorsmentioning

confidence: 99%

Detection of Aβ Monomers and Oligomers: Early Diagnosis of Alzheimer's Disease

Zhou

Liu

Hao

et al. 2016

Chemistry An Asian Journal

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“…Peptoids are promising materials for biomedical and nanoscience research because they are robust and synthetically flexible yet sequence-specific and highly tunable 5 . Peptoids have demonstrated biological activity (therapeutics 6,7 , diagnostics 8 , intracellular delivery [9][10] ) and folding into hierarchical nanostructures 3,[11][12][13][14] …”

Section: Applications and Significancementioning

confidence: 99%

Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets

Tran

Gael

Connolly

et al. 2011

JoVE

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Peptoids are a novel class of biomimetic, non-natural, sequence-specific heteropolymers that resist proteolysis, exhibit potent biological activity, and fold into higher order nanostructures. Structurally similar to peptides, peptoids are poly N-substituted glycines, where the side chains are attached to the nitrogen rather than the alpha-carbon. Their ease of synthesis and structural diversity allows testing of basic design principles to drive de novo design and engineering of new biologically-active and nanostructured materials.Here, a simple manual peptoid synthesis protocol is presented that allows the synthesis of long chain polypeptoids ( up to 50mers) in excellent yields. Only basic equipment, simple techniques (e.g. liquid transfer, filtration), and commercially available reagents are required, making peptoids an accessible addition to many researchers' toolkits. The peptoid backbone is grown one monomer at a time via the submonomer method which consists of a two-step monomer addition cycle: acylation and displacement. First, bromoacetic acid activated in situ with N,N'-diisopropylcarbodiimide acylates a resin-bound secondary amine. Second, nucleophilic displacement of the bromide by a primary amine follows to introduce the side chain. The two-step cycle is iterated until the desired chain length is reached. The coupling efficiency of this two-step cycle routinely exceeds 98% and enables the synthesis of peptoids as long as 50 residues. Highly tunable, precise and chemically diverse sequences are achievable with the submonomer method as hundreds of readily available primary amines can be directly incorporated.Peptoids are emerging as a versatile biomimetic material for nanobioscience research because of their synthetic flexibility, robustness, and ordering at the atomic level. The folding of a single-chain, amphiphilic, information-rich polypeptoid into a highly-ordered nanosheet was recently demonstrated. This peptoid is a 36-mer that consists of only three different commercially available monomers: hydrophobic, cationic and anionic. The hydrophobic phenylethyl side chains are buried in the nanosheet core whereas the ionic amine and carboxyl side chains align on the hydrophilic faces. The peptoid nanosheets serve as a potential platform for membrane mimetics, protein mimetics, device fabrication, and sensors. Methods for peptoid synthesis, sheet formation, and microscopy imaging are described and provide a simple method to enable future peptoid nanosheet designs. Video LinkThe video component of this article can be found at https://www.jove.com/video/3373/ Protocol Solid-Phase Submonomer Synthesis of PolypeptoidsSolid-phase synthesis (SPS) is a common technique used to synthesize sequence-specific biopolymers step-wise, directly on an inert solidsupport such as a polymeric resin bead. High coupling yields and ease of excess reactant removal are major advantages of SPS. After a coupling reaction to the resin, excess reagents are simply drained and the beads are washed to be ready for the next rea...

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“…in today's world. [1][2][3][4][5] Misfolded proteins have the potential to interact with one another creating toxic aggregates, amyloids, which are most commonly known for fibril accumulation and an increase in b-sheet content.…”

Section: Introductionmentioning

confidence: 99%

“…15,16 Recent studies have also shown that AD can occur without the presence of fibril plaques and suggest that the small soluble Ab oligomers are the likely neurotoxic agent that is associated with the progress of AD. 1,6,[9][10][11][12][17][18][19][20] The formation of oligomers are believed to be intracellular and can potentially affect synapse functions, disruption of glutamate uptake, and prevent the ability to maintain proper memory. 1,3,17,21 Since the oligomer aggregates are unstable and time dependent, the exact shape, size, and pathological pathway are hard to determine.…”

Section: Introductionmentioning

confidence: 99%

“…1,6,[9][10][11][12][17][18][19][20] The formation of oligomers are believed to be intracellular and can potentially affect synapse functions, disruption of glutamate uptake, and prevent the ability to maintain proper memory. 1,3,17,21 Since the oligomer aggregates are unstable and time dependent, the exact shape, size, and pathological pathway are hard to determine. 22,23 A variety of techniques, including native page, enzyme-linked immunosorbent assay, light scattering, mass spectrometry, and size exclusion chromatography, have been used to study Ab as reviewed in depth by Pryor et al 24 Many previous studies have highlighted the difficulty in narrowing the type of intermediate aggregates formed (such as ADDLs (amyloid beta-derived diffusible ligands), oligomers <30 kDa, fibrillar oligomer, and protofibrils) and in analyzing Ab without causing alternative aggregate pathways due to experimentation.…”

Section: Introductionmentioning

confidence: 99%

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Field amplified sample stacking of amyloid beta (1-42) oligomers using capillary electrophoresis

Paracha

Hestekin

2016

Biomicrofluidics

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Oligomeric forms of the amyloid beta (Aβ) protein have been indicated to be an important factor in the development of Alzheimer's disease (AD). Since the oligomeric forms of Aβ can vary in size and conformation, it is vital to understand the early stages of Aβ aggregation in order to improve the care and treatment of patients with AD. This is the first study to determine the effect of field amplified sample stacking (FASS) on the separation of oligomeric forms of Aβ1-42 using capillary electrophoresis (CE) with ultraviolet (UV) detection. UV-CE was able to separate two different species of Aβ1-42 oligomers (<7 mers and 7–22 mers). Although FASS required the use of a higher ionic strength buffer, Aβ1-42 oligomers had the same aggregation behavior as under the non-FASS conditions with only small changes in the amounts of oligomers observed. In general, FASS provided smaller peak widths (>75% average reduction) and increased peak heights (>60% average increase) when compared to non-FASS conditions. UV-CE with FASS also provided higher resolution between the Aβ1-42 oligomers for all aggregation time points studied. In addition, Congo red and Orange G inhibition studies were used to help evaluate the conformation of the observed species. This work demonstrates the ability of UV-CE employing FASS to provide higher resolution between oligomeric forms of Aβ1-42 without significantly altering their aggregation.

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A Universal Method for Detection of Amyloidogenic Misfolded Proteins

Cited by 35 publications

References 55 publications

Detection of Aβ Monomers and Oligomers: Early Diagnosis of Alzheimer's Disease

Detection of Aβ Monomers and Oligomers: Early Diagnosis of Alzheimer's Disease

Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets

Field amplified sample stacking of amyloid beta (1-42) oligomers using capillary electrophoresis

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