Paired helical filaments contain small amounts of cholesterol, phosphatidylcholine and sphingolipids

Abstract

By using qualitative and quantitative high-performance thin layer chromatography (hpTLC) we found lipids associated with purified Alzheimer's (AD) paired helical filaments (PHF) in an amount of 1.4+/-0.2% of the total anhydrous mass. Compared to normal brain tissue these lipids have an unusual lipid class composition. The most prominent lipid classes were phosphatidylcholine (PC), cholesterol (CH), galactocerebrosides (GC) and sphingomyelin (SM). In addition, the use of micro high-performance liquid chromatography (HPLC) in combination with matrix-assisted laser desorption and ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) allowed the determination of the molecular species of the polar membrane lipid classes present in PHF. The lipid pattern of intracellular PHF shows many characteristics of the conserved lipid pattern previously described for extracellular amyloid fibrils, suggesting similarities in their pathway of formation.

Membrane permeabilization by Islet Amyloid Polypeptide

“…Importantly, this study shows that pre-formed hIAPP fibrils and the nonamyloidogenic rIAPP do not permeabilize membranes, whereas allowing hIAPP to aggregate at the membrane, starting from a monomeric hIAPP population, leads to fibril growth at the membrane and concomitant membrane permeabilization. The uptake of lipids into forming amyloid has been observed before under in vitro conditions (Sparr, et al 2004;Zhao, et al 2004;Domanov, et al 2008), and also in various types of amyloid that was isolated from patients (Gellermann, et al 2005;Gellermann, et al 2006). …”

Significant sensitivity improvements by matrix optimization: a MALDI-TOF mass spectrometric study of lipids from hen egg yolk

“…Additionally, it is well known that SM is much less sensitively detectable than PC despite the presence of the quaternary ammonia headgroups in both cases (Gellermann et al, 2006). Finally, it should be noted that PEs are only detectable with very low sensitivities and exclusively in the presence of DHB, which allows for the detection of the corresponding sodiated ion species (2a).…”

Significance of molecular crowding in grana membranes of higher plants for light harvesting by photosystem II

“…The two-dimensional run was carried out according to (Christie and Dobson 1999). The developed and dried plate was dipped in a bath containing 10% copper sulphate and 7.5% phosphoric acid (Gellermann et al 2006) and heated (170°C) for about 7 min. After scanning the plate the resulting 8-bit gray scale image was analysed with the image processing software Optimas (Media Cybernetics, Silver Spring, MD, USA).…”