Malavolta Luciana, Pinto Marcelo R S, Nakaie Clóvis R
Department of Physiological Sciences, Faculdade de Ciências Médicas da Santa Casa de Sao Paulo, SP, Brazil.
Protein Pept Lett. 2013 Aug;20(8):848-55. doi: 10.2174/0929866511320080002.
This work developed an alternative approach targeting the evaluation of the aggregation propensity of the (1-42) β-amyloid peptide (Alzheimer's disease) and some segments, either attached to a polymer during their synthesis or when free in solution. The solvation behavior of peptide-resins was gauged by measuring the swelling of beads in a microscope and the degree of chain motion through EPR spectra of previously labeled resins with an amino acid-type probe. In terms of comparative solvent dissociation power towards aggregated structures, the findings revealed greater values of peptide-resin swelling, peptide chain mobility and solubility when in strong electron donor dimethylsulfoxide than in strong electron acceptor trifluoroethanol. Otherwise, the weakest chain-chain disruption power was verified for acetonitrile, an internally neutral solvent in terms of Lewis acid/base properties. In complement, fluorescence and light scattering experiments depicted that the 15-35 region plays an essential role in the amyloid peptide fibril formation capacity.
这项工作开发了一种替代方法，用于评估（1-42）β-淀粉样肽（阿尔茨海默病）及其某些片段的聚集倾向，这些片段在合成过程中与聚合物相连，或者在溶液中游离时。通过在显微镜下测量珠子的溶胀以及通过用氨基酸型探针预先标记的树脂的电子顺磁共振光谱来测量链运动程度，来衡量肽树脂的溶剂化行为。就对聚集结构的比较溶剂解离能力而言，研究结果表明，当处于强电子供体二甲基亚砜中时，肽树脂的溶胀、肽链流动性和溶解度的值比处于强电子受体三氟乙醇中时更大。否则，就路易斯酸/碱性质而言，内部呈中性的溶剂乙腈的链链破坏能力最弱。此外，荧光和光散射实验表明，15-35区域在淀粉样肽纤维形成能力中起着至关重要的作用。
