Complete identification of all 20 relevant epimeric peptides in β-amyloid: a new HPLC-MS based analytical strategy for Alzheimer's research

Du, Shoucheng; Readel, Elizabeth R.; Wey, Michael; Armstrong, Daniel W.

doi:10.1039/c9cc09080k

Cited by 22 publications

(15 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… 35–39 Chiral chromatography was shown to separate synthetic Aβ epimers and isomers containing Asp and Ser residues. 40 Ion mobility separation-mass spectrometry (IMS-MS) is a powerful tool for the analysis and characterization of isomerized and epimerized peptides in the gas phase. 41–45 Recently, synthetic tryptic Aβ peptide isomers have been shown to resolve in IMS-MS using structures for lossless ion manipulations (SLIM).…”

Section: Introductionmentioning

confidence: 99%

Quantification of N-terminal amyloid-β isoforms reveals isomers are the most abundant form of the amyloid-β peptide in sporadic Alzheimer’s disease

Mukherjee

Perez

Lago

et al. 2021

Brain Communications

View full text Add to dashboard Cite

Plaques that characterize Alzheimer’s disease accumulate over 20 years as a result of decreased clearance of amyloid-β peptides. Such long-lived peptides are subjected to multiple post-translational modifications, in particular isomerization. Using liquid chromatography ion mobility separations mass spectrometry, we characterized the most common isomerized amyloid-β peptides present in the temporal cortex of sporadic Alzheimer’s disease brains. Quantitative assessment of amyloid-β N-terminus revealed that > 80% of aspartates (Asp-1 and Asp-7) in the N-terminus was isomerized, making isomerization the most dominant post-translational modification of amyloid-β in Alzheimer’s disease brain. Total amyloid-β1-15 was ∼ 85% isomerized at Asp-1 and/or Asp-7 residues, with only 15% unmodified amyloid-β1-15 left in Alzheimer’s disease. While amyloid-β4-15 the next most abundant N-terminus found in Alzheimer’s disease brain, was only ∼ 50% isomerized at Asp-7 in Alzheimer’s disease. Further investigations into different biochemically defined amyloid-β-pools indicated a distinct pattern of accumulation of extensively isomerized amyloid-β in the insoluble fibrillar plaque and membrane associated pools, while the extent of isomerization was lower in peripheral membrane/vesicular and soluble pools. This pattern correlated with the accumulation of aggregation prone amyloid-β42 in Alzheimer’s disease brains. Isomerization significantly alters the structure of the amyloid-β peptide, which not only has implications for its degradation, but also for oligomer assembly, and the binding of therapeutic antibodies that directly target the N-terminus, where these modifications are located.

show abstract

Section: Introductionmentioning

confidence: 99%

Quantification of N-terminal amyloid-β isoforms reveals isomers are the most abundant form of the amyloid-β peptide in sporadic Alzheimer’s disease

Mukherjee

Perez

Lago

et al. 2021

Brain Communications

View full text Add to dashboard Cite

show abstract

“…With this approach, various enzymes or a combination of enzymes with different amino acid enantiomers at specific cleavage sites can be used. As an example, trypsin in association with endoproteinase Asp-N (cleavage at N-terminus L-Asp) [63], L-isoaspartyl methyltransferase (PIMT) (methylation of L-isoAsp) [14,32,35,37,63] and Daspartyl endoproteinase (DEAP) also named paenidase (cleavage at C-terminus D-Asp) [64] can recognize only L-α-Asp, L-β-Asp and D-α-Asp residues respectively. Other proteases can be used to cleave proteins at specific sites, such as glutamyl endoproteinase Glu-C (cleavage at C-terminus L-Glu) for histone H2B [32] and human immunoglobulin G kappa chain [15] analyses.…”

Section: Determination Of Chiral Protein Sequencesmentioning

confidence: 99%

Recent Advances in Chiral Analysis of Proteins and Peptides

Morvan

Mikšı́k

2021

Separations

View full text Add to dashboard Cite

Like many biological compounds, proteins are found primarily in their homochiral form. However, homochirality is not guaranteed throughout life. Determining their chiral proteinogenic sequence is a complex analytical challenge. This is because certain D-amino acids contained in proteins play a role in human health and disease. This is the case, for example, with D-Asp in elastin, β-amyloid and α-crystallin which, respectively, have an action on arteriosclerosis, Alzheimer's disease and cataracts. Sequence-dependent and sequence-independent are the two strategies for detecting the presence and position of D-amino acids in proteins. These methods rely on enzymatic digestion by a site-specific enzyme and acid hydrolysis in a deuterium or tritium environment to limit the natural racemization of amino acids. In this review, chromatographic and electrophoretic techniques, such as LC, SFC, GC and CE, will be recently developed (2018–2020) for the enantioseparation of amino acids and peptides. For future work, the discovery and development of new chiral stationary phases and derivatization reagents could increase the resolution of chiral separations.

show abstract

Section: Future Perspectivesmentioning

confidence: 99%

“…On the separation front, 2-D reversed-phase LC and chiral LC − have demonstrated capabilities to resolve peptide epimers. In a recent example, 20 epimers of amyloid β (Aβ) (1–42) peptide were completely resolved by a MS-compatible chiral chromatography method after the sample was digested with trypsin . This example suggested that combination of enzymatic digestion and an optimized chiral LC method could be a general approach to completely resolve epimers of large peptides prior to MS analysis.…”

Section: Future Perspectivesmentioning

confidence: 99%

“…In a recent example, 20 epimers of amyloid β (Aβ) (1−42) peptide were completely resolved by a MS-compatible chiral chromatography method after the sample was digested with trypsin. 42 This example suggested that combination of enzymatic digestion and an optimized chiral LC method could be a general approach to completely resolve epimers of large peptides prior to MS analysis. In recent years, high resolution ion-mobility spectrometry has emerged as a direct, rapid, and effective method of choice in resolving peptide epimers in the gas phase.…”

Section: ■ Future Perspectivesmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of Synthetic Peptide Therapeutics Using Liquid Chromatography–Mass Spectrometry: Challenges, Solutions, Pitfalls, and Future Perspectives

Lian

Wang

Tian

et al. 2021

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Synthetic peptides represent an important and expanding class of therapeutics. Despite having a relatively small size as compared to monoclonal antibodies and other proteins, synthetic peptides are subject to many complex structural modifications originating from the starting materials, manufacturing process, and storage conditions. Although mass spectrometry has been increasingly used to characterize impurities of synthetic peptides, systematic review of this field is scarce. In this paper, an overview of the impurities in synthetic peptide therapeutics is provided in the context of how the knowledge from detailed characterization of the impurities using liquid chromatography–mass spectrometry (LC–MS) can be used to develop the manufacturing process and control strategy for synthetic peptide therapeutics following the critical quality attribute (CQA)-driven and risk-based approach. The thresholds for identifying and controlling the impurities are discussed based on currently available regulatory guidance. Specific LC–MS techniques for identification of various types of impurities based on their structural characteristics are discussed with the focus on structural isomers and stereoisomers (i.e., peptide epimers). Absolute and relative quantitation methods for the peptide impurities are critiqued. Potential pitfalls in characterization of synthetic peptide therapeutics using LC–MS are discussed. Finally, a systematic LC–MS workflow for characterizing the impurities in synthetic peptide therapeutics is proposed, and future perspectives on applying emerging LC–MS techniques to address the remaining challenges in the development of synthetic peptide therapeutics are presented.

show abstract

Complete identification of all 20 relevant epimeric peptides in β-amyloid: a new HPLC-MS based analytical strategy for Alzheimer's research

Abstract: Although the underlying cause of Alzheimer's disease (AD) is not known, detection of racemization/isomerization of Asp and Ser in β-amyloid (Aβ) may be crucial.

Cited by 22 publications

References 40 publications

Quantification of N-terminal amyloid-β isoforms reveals isomers are the most abundant form of the amyloid-β peptide in sporadic Alzheimer’s disease

Quantification of N-terminal amyloid-β isoforms reveals isomers are the most abundant form of the amyloid-β peptide in sporadic Alzheimer’s disease

Recent Advances in Chiral Analysis of Proteins and Peptides

Characterization of Synthetic Peptide Therapeutics Using Liquid Chromatography–Mass Spectrometry: Challenges, Solutions, Pitfalls, and Future Perspectives

Contact Info

Product

Resources

About