Analysis of the core components of Alzheimer paired helical filaments A gas chromatography/mass spectrometry characterization of fatty acids, carbohydrates and long‐chain bases

Goux, Warren J.; Rodrı́guez, Santiago; Sparkman, Dennis R.

doi:10.1016/0014-5793(95)00486-s

Cited by 29 publications

(24 citation statements)

References 29 publications

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“…In the hydrolyzed sample no resonances appear in the downfield region of the spectrum, suggesting that the resonances at 5.21 ppm in the spectrum of the native structure arise from carbohydrate anomeric protons rather than olefinic protons of unsaturated fatty acid or a sphingosine base. The absence of resonances attributable to a sphingosine base in the NMR spectrum confirms our earlier results obtained by GC/MS (Goux et al, 1995a). Chemical shifts and coupling constants for the two anomeric doublets are consistent with those of an equilibrium mixture of a-and /3-glucopyranoses.…”

Section: Nmr and Gc/ms Linkage Analysis Of Phf-associated Glycolipidsupporting

confidence: 88%

“…We have recently shown that the carbohydrate component of the unique glycolipid associated with prcPHF is glucose and that the lipid component is mostly stearic and palmitic acids with <10% unsaturated fatty acids (Goux et al, 1995a). Comparison of the carbohydrate and fatty acid profile with similar data for other brain glycolipids has demonstrated that the PHF-associated glycolipid is structurally unique and distinct from other brain cerebrosides, gangliosides, and phospholipids.…”

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confidence: 86%

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Characterization of the Glycolipid Associated with Alzheimer Paired Helical Filaments

Goux

Rodrı́guez

Sparkman

1996

Journal of Neurochemistry

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In the present study, analytical techniques including gas chromatography/mass spectrometry (GC/ MS) -assisted carbohydrate linkage-analysis, one-and two-dimensional NM R, and matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-MS) have been used to characterize the structure of the glycolipid associated with the paired helical filaments (PHF) isolated from the neurofibrillary tangles of Alzheimer's diseased brain. The 1H NMR spectrum of acidhydrolyzed protein-resistant core PH F (prcPH F) displays resonances that can be assigned to fatty acid and glucose. There are no resonances present that would indicate the presence of protein, amino acids, or a sphingosine base. Using two-dimensional homonuclear correlated spectroscopy, homonuclear Hartmann-Hahn, and heteronuclear multiple quantum coherence experiments, resonances in the 1H and 130 NMR spectrum of native PHF were assigned to a nonreducing terminal a-i ,6-glycosidically linked glucose, an internal a-i 6-linked glucose, and an a-i 2,6-linked glucose. The narrow linewidths observed for these residues suggest that they arise from glucose residues undergoing rapid segmental motion. The carbohydrate portion of the PHF-associated glycolipid was analyzed using GO/MS linkage analysis and confirmed the presence of terminal and internal a-1,6-linked glucose and a-i 2,6-linked glucose in a molar ratio of 2:1:1. Three components of the PHF-associated glycolipid fraction having masses 2,416, 2,325, and 2,237 Da were observed using MALDI-MS. The least abundant, heavier mass component (2,416 Da) was best fit to a structure with a tridecamer of glucose having a single esterified 020 fatty acid (Glc 13 + 020 or G1c13 + 020.1), whereas the more abundant, lower mass components were best fit to noncovalently associated glycolipid dimers, each with a glucose pentamer or hexamer having two 014, 016, or 018 esterified fatty acids {D[(G1c5 + 018) + (G1c6 + 016)1 or D[(G1c5 + 014) + (G1c6 + 014)]}. The ratio of glucose to fatty acid calculated from these bestfit structures of the more abundant mass components (5.5 + 1.1:1.0) is in reasonable agreement with the same ratio calculated from peak integrations in the NMR spectra of acid-hydrolyzed prcPHF (6.2 ± 1.6). Structural similarities between PHF-associated glycolipid and other glycolipid amphiphiles known to form PHF-like filaments indirectly suggest that this unique glycolipid may be an integral component of the PHF suprastructure.

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Section: Nmr and Gc/ms Linkage Analysis Of Phf-associated Glycolipidsupporting

confidence: 88%

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confidence: 86%

Characterization of the Glycolipid Associated with Alzheimer Paired Helical Filaments

Goux

Rodrı́guez

Sparkman

1996

Journal of Neurochemistry

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“…Our own electron microscopic observations on AD brain biopsies suggest NFT are derived from collapsing mitochondria and other intraneuronal pathological organelles, supporting the contention that NFT are the result of damaged cytomembranes [29]. Chemical analysis of the protease resistant core of paired helical filaments revealed associated glycolipids [30], [31] that could originate from membrane walls.…”

Section: Resultssupporting

confidence: 67%

Alzheimer's Disease and Non-Demented High Pathology Control Nonagenarians: Comparing and Contrasting the Biochemistry of Cognitively Successful Aging

et al. 2011

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The amyloid cascade hypothesis provides an economical mechanistic explanation for Alzheimer's disease (AD) dementia and correlated neuropathology. However, some nonagenarian individuals (high pathology controls, HPC) remain cognitively intact while enduring high amyloid plaque loads for decades. If amyloid accumulation is the prime instigator of neurotoxicity and dementia, specific protective mechanisms must enable these HPC to evade cognitive decline. We evaluated the neuropathological and biochemical differences existing between non-demented (ND)-HPC and an age-matched cohort with AD dementia. The ND-HPC selected for our study were clinically assessed as ND and possessed high amyloid plaque burdens. ELISA and Western blot analyses were used to quantify a group of proteins related to APP/Aβ/tau metabolism and other neurotrophic and inflammation-related molecules that have been found to be altered in neurodegenerative disorders and are pivotal to brain homeostasis and mental health. The molecules assumed to be critical in AD dementia, such as soluble or insoluble Aβ40, Aβ42 and tau were quantified by ELISA. Interestingly, only Aβ42 demonstrated a significant increase in ND-HPC when compared to the AD group. The vascular amyloid load which was not used in the selection of cases, was on the average almost 2-fold greater in AD than the ND-HPC, suggesting that a higher degree of microvascular dysfunction and perfusion compromise was present in the demented cohort. Neurofibrillary tangles were less frequent in the frontal cortices of ND-HPC. Biochemical findings included elevated vascular endothelial growth factor, apolipoprotein E and the neuroprotective factor S100B in ND-HPC, while anti-angiogenic pigment epithelium derived factor levels were lower. The lack of clear Aβ-related pathological/biochemical demarcation between AD and ND-HPC suggests that in addition to amyloid plaques other factors, such as neurofibrillary tangle density and vascular integrity, must play important roles in cognitive failure.

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“…Therefore, a structured, protease-resistant component may also be contained in PHF. This protease-resistant core of PHF has been described as being non-proteinaceous (Sparkman, 1993) and later as 'glycolipid' containing mainly 1,6-linked glucose (Goux et al, 1995(Goux et al, , 1996. However, the experimental details mentioned in the publications above can as well be interpreted as a polysaccharide scaffold with a minor extent of fatty acid modification or impurities.…”

Section: Functional Implications Of the Polysaccharide Scaffoldmentioning

confidence: 95%

Prion Rods Contain an Inert Polysaccharide Scaffold

Appel¹,

Dumpitak²,

Matthiesen³

et al. 1999

Biological Chemistry

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A polysaccharide consisting of mainly 1,4-linked glucose units was found associated with prion rods, which are composed mainly of insoluble aggregates of the N-terminally truncated prion protein (PrP 27-30) exhibiting the ultrastructural and tinctorial properties of amyloid. The polysaccharide differs in composition from the Asn-linked oligosaccharides and the GPI-anchor of the prion protein. Prion rods were prepared from scrapie-infected hamster brains using two different purification protocols. Prolonged digestion of rods with proteinase K reduced PrP by a factor of at least 500, leaving about 10% (w/w) of the sample as an insoluble remnant. Only glucose was obtained by acid hydrolysis of the remnant and methylation analysis showed 80% 1,4-, 15% 1,6- and 5% 1,4,6-linked glucose units. The physical and chemical properties as well as the absence of terminal glucose units indicate a very high molecular mass of the polysaccharide. No evidence was found for covalent bonds between PrP and the polysaccharide. The polysaccharide certainly contributes to the unusual chemical and physical stability of prion rods, acting like a scaffold. A potential structural and/or functional relevance of the polysaccharide scaffold is discussed.

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Analysis of the core components of Alzheimer paired helical filaments A gas chromatography/mass spectrometry characterization of fatty acids, carbohydrates and long‐chain bases

Cited by 29 publications

References 29 publications

Characterization of the Glycolipid Associated with Alzheimer Paired Helical Filaments

Characterization of the Glycolipid Associated with Alzheimer Paired Helical Filaments

Alzheimer's Disease and Non-Demented High Pathology Control Nonagenarians: Comparing and Contrasting the Biochemistry of Cognitively Successful Aging

Prion Rods Contain an Inert Polysaccharide Scaffold

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