Soluble oligomers of the amyloid-β peptide have been implicated as proximal neurotoxins in Alzheimer's disease. However, the identity of the neurotoxic aggregate(s) and the mechanisms by which these species induce neuronal dysfunction remain uncertain. Physiologically relevant experimentation is hindered by the low endogenous concentrations of the peptide, the metastability of Aβ oligomers, and...

Chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. These properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (PA) that cannot be controlled when the oligomers are produced by chemical hydrolysis. To determine the infl...

Hyperthermostable proteins are highly resistant to various extreme conditions. Many factors have been proposed to contribute to their ultrahigh structural stability. Some thermostable proteins have larger oligomeric size when compared to their mesophilic homologues. The formation of compact oligomers can minimize the solvent accessible surface area and increase the changes of Gibbs free energy ...

Hyaluronan oligosaccharides (molecular weight: approximately 2.5 x 10(3)) inhibit growth of several types of tumors in vivo. In vitro, the oligomers inhibit anchorage-independent growth of several tumor cell types. In accordance with this finding, the oligomers also induce apoptosis and stimulate caspase-3 activity under anchorage-independent conditions. Since inhibitors of phosphoinositide 3-k...

BACKGROUND Progressive supranuclear palsy (PSP) is a neurodegenerative tauopathy which is primarily defined by the deposition of tau into globose-type neurofibrillary tangles (NFT). Tau in its native form has important functions for microtubule dynamics. Tau undergoes alternative splicing in exons 2, 3, and 10 which results in six different isoforms. Products of splicing on exon 10 are the most...

Formation of alpha-synuclein aggregates is proposed to be a crucial event in the pathogenesis of Parkinson's disease. Large soluble oligomeric species are observed as probable intermediates during fibril formation and these, or related aggregates, may constitute the toxic element that triggers neurodegeneration. Unfortunately, there is a paucity of information regarding the structure and compos...

Amyloid beta (Aβ) oligomers accumulate in the brain tissue of Alzheimer disease patients and are related to disease pathogenesis. The precise mechanisms by which Aβ oligomers cause neurotoxicity remain unknown. We recently reported that Aβ oligomers cause intracellular Ca(2+) overload and neuronal death that can be prevented by NMDA receptor antagonists. This study investigated whether Aβ oligo...

A popular working hypothesis of Alzheimer's disease causation is amyloid β-protein oligomers are the key neuropathogenetic agents. Rigorously elucidating the role of oligomers requires the production of stable oligomers of each size. We previously used zero-length photochemical cross-linking to allow stabilization, isolation, and determination of structure-activity relationships of pure populat...

We have previously reported expression of WT1 in acute leukemia. To elucidate its biological significance, we examined the effect of the suppression of the WT1 expression by WT1 antisense oligomers on the growth of the leukemic cells expressing WT1. When 20 different WT1 antisense (AS) oligomers covering from the 5' cap sites of the WT1 gene to the 3' end were examined for the inhibitory effect...

In amyloid diseases, it is not evident which protein aggregates induce cell death via specific molecular mechanisms and which cause damage because of their mass accumulation and mechanical properties. We showed that equine lysozyme assembles into soluble amyloid oligomers and protofilaments at pH 2.0 and 4.5, 57 degrees C. They bind thioflavin-T and Congo red similar to common amyloid structure...