Amyloid-beta Peptide Oligomerization Assay

Alzheimer's disease (AD), a common neurodegenerative brain disease, is mainly characterized by extracellular amyloid-beta (Aβ) plaque deposition and intracellular neurofibrillary tangles of phosphorylated tau protein, resulting in the loss of brain neurons. In recent years, Aβ peptide oligomerization has attracted much attention due to its effect on AD. In addition to various techniques, Creative Biolabs has developed various cell models such as AD in vitro models to facilitate better results. Creative Biolabs is committed to providing a diverse range of Aβ peptide oligomerization assay services to meet your specific needs.

Background of Aβ Peptide Oligomerization

Aβ is the main component of amyloid plaques, derived from the continuous cleavage of amyloid precursor protein (APP) by β- and γ-secretase. Once released from the precursor, Aβ peptides readily aggregate and can assemble into oligomeric structures. Some experimental data have demonstrated that soluble Aβ oligomers are highly neurotoxic and are the initial steps in AD pathology.

Fig.1 Amyloid β oligomerization. (Rudajev & Novotny, 2020)

Isoforms of Aβ

There are three soluble Aβ peptides: Aβ1-38, Aβ1-40 and Aβ1-42. Among them, Aβ1-40 is the most abundant form. In addition, the other minor abundance forms are 15, 16, 17, 34, 37 and 39 amino acids in length. Notably, while Aβ1-40 is produced at higher levels, Aβ1-42, which is more hydrophobic and prone to aggregate formation, is also more likely to cause neurological damage and memory loss, ultimately forming amyloid deposits in the brain. Currently, studies have found that Aβ1-42 in cerebrospinal fluid can be used as a biomarker in clinical trials to improve the accuracy of AD diagnosis.

Techniques for Detection of Aβ Oligomers at Creative Biolabs

• ELISA-based techniques

Since Aβ oligomers are directly involved in AD pathology, Aβ oligomers are considered as promising biomarkers for the early diagnosis of AD. There are a variety of oligomer-specific assays available at Creative Biolabs, many of which are enzyme-linked immunosorbent assays (ELISAs). The ELISA technique is relatively simple to perform, well suited for high throughput and offers high sensitivity. In recent years, several ELISA-based techniques have been developed, one of which, called surface-based fluorescence intensity distribution analysis (sFIDA), has been applied in many assays.

Fig.2 Scheme of the sFIDA assay. (Kühbach, et al., 2016)

• Biosensor technology

Biosensor technology is also gradually becoming a mainstream technology at Creative Biolabs. For example, methods such as surface plasmon resonance (SPR) or electrochemical impedance spectroscopy (EIS) sensors have been combined with oligomer-specific recognition systems such as antibodies or peptides. Our results show that biosensors are able to provide fast, real-time and accurate results.

Soluble oligomers of Aβ are closely related to AD disease progression, and specific detection and quantification of oligomeric proteins in cerebrospinal fluid may provide detectable biomarkers, paving the way for early diagnosis and prognosis. With diverse cell models and technologies, Creative Biolabs will select the most suitable Aβ oligomer detection scheme according to your experimental needs to facilitate the progress of your project. Please contact us in time for more details.

References

1. Rudajev, V.; Novotny, J. The Role of Lipid Environment in Ganglioside GM1-Induced Amyloid β Aggregation. Oncotarget. 2020, 10(9): 226.
2. Kühbach, K.; et al. Application of an amyloid beta oligomer standard in the sFIDA assay. Frontiers in neuroscience. 2016, 10: 8.