Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING
PZ HTL SA
GLOBETECH PUBLISHING

Analysis Reveals Detailed Structural Features of Amyloid Oligomers

By BiotechDaily International staff writers
Posted on 15 Jul 2013
Image: Molecular structures of amyloid oligomers and amyloid fibers (Photo courtesy of the University of California, Los Angeles).
Image: Molecular structures of amyloid oligomers and amyloid fibers (Photo courtesy of the University of California, Los Angeles).
Advanced analytical analysis of amyloid-beta42 oligomers has yielded insights into the structure of these oligomers that helps to explain the mechanism behind the process of oligomerization and the reasons for their molecular toxicity.

Oligomerization of the 42 amino acid peptide amyloid-beta42 plays a key role in the pathogenesis of Alzheimer disease, but despite great academic and medical interest, the structure of these oligomers has not been well characterized.

In the current study, investigators at the University of California, Los Angeles (USA) employed several advanced analytical techniques to delve the secrets of the oligomeric (globulomeric) form of amyloid-beta42. They reported in the June 28, 2013, issue of the Journal of Biological Chemistry that transmission electron microscopy showed amyloid-beta42 oligomers were globular structures with diameters of about seven to eight nanometers. Circular dichroism revealed primarily beta-structures, while X-ray powder diffraction suggested a highly ordered intrasheet hydrogen-bonding network with heterogeneous intersheet packing. Residue-level mobility analysis on spin labels introduced at 14 different positions showed a structured state but with a disordered state at all labeling sites. Side chain mobility analysis suggested that structural order increased from N- to C-terminal regions. Intermolecular distance measurements at 14 residue positions suggested that C-terminal residues glycine-29 to valine-40 formed a tightly packed core with intermolecular distances in a narrow range of 1.15–1.25 nm.

The authors suggested that the significant structural and organizational differences that distinguished amyloid-beta42 globulomers from the free peptide and amyloid-plaque forms may help to explain the lack of success of experimental anti-Alzheimer's disease drugs that targeted amyloid plaques while ignoring the globulomeric form of the molecule.

Related Links:
University of California, Los Angeles



Channels

Drug Discovery

view channel
Image: Chitosan is derived from the shells of shrimp and other sea crustaceans, including Alaskan pink shrimp, pictured here (Photo courtesy of NOAA - [US] National Oceanic and Atmospheric Administration).

Chitosan Treatment Clears the Way for Antibiotics to Eliminate Recurrent Urinary Tract Infections

Recurrent urinary tract infection was successfully resolved in a mouse model by treatment with the exfoliant chitosan followed by a round of antibiotics. Bacterial urinary tract infection (UTI), most... Read more

Biochemistry

view channel

Mitochondrial Cause of Aging Can Be Reversed

Researchers have found a cause of aging in lab animals that can be reversed, possibly providing an avenue for new treatments for age-related diseases including type 2 diabetes, cancer, muscle wasting, and inflammatory diseases. The researchers plan to begin human trials late 2014. The study, which was published December... Read more

Therapeutics

view channel

Cytokine Identified That Causes Mucositis in Cancer Therapy Patients

The action of the cytokine interleukin 1-beta (IL-1beta) has been found to underlie the onset of mucositis, a common, severe side effect of chemotherapy and irradiation of cancer patients. Mucositis occurs as a result of cell death in reaction to chemo- or radiotherapy. The mucosal lining of the mouth becomes thin, may... Read more

Business

view channel

Analytical Sciences Trade Fair Declared a Rousing Success

Organizers of this year's 24th "analytica" biosciences trade fair have reported significant increases in both the number of visitors and exhibitors compared to the 2012 event. The analytica trade fair for laboratory technology, analysis, and biotechnology has been held at the Munich (Germany) Trade Fair Center every... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.