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Synchrotron FTIR micro-spectroscopy for structural analysis of Lewy bodies in the brain of Parkinson's disease patients.

Araki K, Yagi N, Ikemoto Y, Yagi H, Choong CJ, Hayakawa H, Beck G, Sumi H, Fujimura H, Moriwaki T, Nagai Y, Goto Y, Mochizuki H - Sci Rep (2015)

Bottom Line: Thus, we used synchrotron Fourier transform infrared micro-spectroscopy (FTIRM) to analyse the fine structure of LBs in the brain of PD patients.Our results showed a shift in the infrared spectrum that indicates abundance of a β-sheet-rich structure in LBs.Also, 2D infrared mapping of LBs revealed that the content of the β-sheet structure is higher in the halo than in the core, and the core contains a large amount of proteins and lipids.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.

ABSTRACT
Lewy bodies (LBs), which mainly consist of α-synuclein (α-syn), are neuropathological hallmarks of patients with Parkinson's disease (PD). The fine structure of LBs is unknown, and LBs cannot be made artificially. Nevertheless, many studies have described fibrillisation using recombinant α-syn purified from E. coli. An extremely fundamental problem is whether the structure of LBs is the same as that of recombinant amyloid fibrils. Thus, we used synchrotron Fourier transform infrared micro-spectroscopy (FTIRM) to analyse the fine structure of LBs in the brain of PD patients. Our results showed a shift in the infrared spectrum that indicates abundance of a β-sheet-rich structure in LBs. Also, 2D infrared mapping of LBs revealed that the content of the β-sheet structure is higher in the halo than in the core, and the core contains a large amount of proteins and lipids.

No MeSH data available.


Related in: MedlinePlus

FTIR spectra.(A) CH stretch region and (B) amide I and II region from the (a) core of an LB, (b) halo of an LB, and (c) normal brain tissue. Red boxes represent characteristic absorption region for lipids or proteins.
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f1: FTIR spectra.(A) CH stretch region and (B) amide I and II region from the (a) core of an LB, (b) halo of an LB, and (c) normal brain tissue. Red boxes represent characteristic absorption region for lipids or proteins.

Mentions: FTIR is an established structural analysis method and is sensitive to the secondary structure of proteins (Fig. 1). An absorption maxima for α-helix (~1655 cm−1), β-sheet (~1630 cm−1), and random coil (~1645 cm−1) structures are included in the frequency range of the amide I band2830. FTIR also provides information on the amount of lipids in the beam31. Because FTIR shows the spectrum derived from a chemical bond, it provides detailed structural information that cannot be obtained with staining and EM. However, FTIR measurement of LBs is not easy for several reasons. The main difficulty is that LBs are too small to be irradiated with an infrared beam, and their density is too low to obtain a significant signal. To overcome this, a strong and small infrared beam is required. For this reason, we used synchrotron radiation at the SPring-8 synchrotron radiation facility (Hyogo, Japan) (Fig. 2). Here, we present, to our knowledge, the first data on the secondary structure of LBs that was obtained using synchrotron Fourier transform infrared micro-spectroscopy (FTIRM). Furthermore, β-sheet mapping was performed to elucidate the process of generation of LBs.


Synchrotron FTIR micro-spectroscopy for structural analysis of Lewy bodies in the brain of Parkinson's disease patients.

Araki K, Yagi N, Ikemoto Y, Yagi H, Choong CJ, Hayakawa H, Beck G, Sumi H, Fujimura H, Moriwaki T, Nagai Y, Goto Y, Mochizuki H - Sci Rep (2015)

FTIR spectra.(A) CH stretch region and (B) amide I and II region from the (a) core of an LB, (b) halo of an LB, and (c) normal brain tissue. Red boxes represent characteristic absorption region for lipids or proteins.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664933&req=5

f1: FTIR spectra.(A) CH stretch region and (B) amide I and II region from the (a) core of an LB, (b) halo of an LB, and (c) normal brain tissue. Red boxes represent characteristic absorption region for lipids or proteins.
Mentions: FTIR is an established structural analysis method and is sensitive to the secondary structure of proteins (Fig. 1). An absorption maxima for α-helix (~1655 cm−1), β-sheet (~1630 cm−1), and random coil (~1645 cm−1) structures are included in the frequency range of the amide I band2830. FTIR also provides information on the amount of lipids in the beam31. Because FTIR shows the spectrum derived from a chemical bond, it provides detailed structural information that cannot be obtained with staining and EM. However, FTIR measurement of LBs is not easy for several reasons. The main difficulty is that LBs are too small to be irradiated with an infrared beam, and their density is too low to obtain a significant signal. To overcome this, a strong and small infrared beam is required. For this reason, we used synchrotron radiation at the SPring-8 synchrotron radiation facility (Hyogo, Japan) (Fig. 2). Here, we present, to our knowledge, the first data on the secondary structure of LBs that was obtained using synchrotron Fourier transform infrared micro-spectroscopy (FTIRM). Furthermore, β-sheet mapping was performed to elucidate the process of generation of LBs.

Bottom Line: Thus, we used synchrotron Fourier transform infrared micro-spectroscopy (FTIRM) to analyse the fine structure of LBs in the brain of PD patients.Our results showed a shift in the infrared spectrum that indicates abundance of a β-sheet-rich structure in LBs.Also, 2D infrared mapping of LBs revealed that the content of the β-sheet structure is higher in the halo than in the core, and the core contains a large amount of proteins and lipids.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.

ABSTRACT
Lewy bodies (LBs), which mainly consist of α-synuclein (α-syn), are neuropathological hallmarks of patients with Parkinson's disease (PD). The fine structure of LBs is unknown, and LBs cannot be made artificially. Nevertheless, many studies have described fibrillisation using recombinant α-syn purified from E. coli. An extremely fundamental problem is whether the structure of LBs is the same as that of recombinant amyloid fibrils. Thus, we used synchrotron Fourier transform infrared micro-spectroscopy (FTIRM) to analyse the fine structure of LBs in the brain of PD patients. Our results showed a shift in the infrared spectrum that indicates abundance of a β-sheet-rich structure in LBs. Also, 2D infrared mapping of LBs revealed that the content of the β-sheet structure is higher in the halo than in the core, and the core contains a large amount of proteins and lipids.

No MeSH data available.


Related in: MedlinePlus