Amyloid-ß-Secondary Structure Distribution in Cerebrospinal Fluid and Blood Measured by an Immuno-Infrared-Sensor: A Biomarker Candidate for Alzheimer's Disease.
Anal Chem
; 88(5): 2755-62, 2016 Mar 01.
Article
en En
| MEDLINE
| ID: mdl-26828829
ABSTRACT
The misfolding of the Amyloid-beta (Aß) peptide into ß-sheet enriched conformations was proposed as an early event in Alzheimer's Disease (AD). Here, the Aß peptide secondary structure distribution in cerebrospinal fluid (CSF) and blood plasma of 141 patients was measured with an immuno-infrared-sensor. The sensor detected the amide I band, which reflects the overall secondary structure distribution of all Aß peptides extracted from the body fluid. We observed a significant downshift of the amide I band frequency of Aß peptides in Dementia Alzheimer type (DAT) patients, which indicated an overall shift to ß-sheet. The secondary structure distribution of all Aß peptides provides a better marker for DAT detection than a single Aß misfold or the concentration of a specific oligomer. The discrimination between DAT and disease control patients according to the amide I frequency was in excellent agreement with the clinical diagnosis (accuracy 90% for CSF and 84% for blood). The amide I band maximum above or below the decisive marker frequency appears as a novel spectral biomarker candidate of AD. Additionally, a preliminary proof-of-concept study indicated an amide I band shift below the marker band already in patients with mild cognitive impairment due to AD. The presented immuno-IR-sensor method represents a promising, simple, robust, and label-free diagnostic tool for CSF and blood analysis.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Biomarcadores
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Péptidos beta-Amiloides
/
Enfermedad de Alzheimer
Tipo de estudio:
Observational_studies
Límite:
Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Anal Chem
Año:
2016
Tipo del documento:
Article
País de afiliación:
Alemania