Search results for "Aggregation"
showing 10 items of 566 documents
The risk of minor depression in families of probands with major depression: sex differences and familiality.
1992
Currently it is not clear whether minor forms of unipolar depression not matching the criteria of “major depression” should be considered as a separate diagnostic category. A controlled family study examined the familial aggregation of minor depression among probands with unipolar major depression. In the families of these probands the relative risk for minor depression was elevated by a similar magnitude to the risk for major depression. Threrefore, the diagnostic category “minor depression” would not increase diagnostic sensitivity at the expense of diagnostic specificity as far as familiality is the criterion. In agreement with recent epidemiological studies, minor depression did not rev…
The impact of the endogenous subtype on the familial aggregation of unipolar depression.
1991
The endogenous/non-endogenous distinction of unipolar major depression is widely accepted, as is the family study approach to the validation of diagnostic distinctions. Rates of affective disorders were examined in 689 first-degree relatives of 184 patients with unipolar major depression and were compared with 312 first-degree relatives of 80 healthy controls. Only unipolar depression and alcoholism were more common in families of depressed probands compared with families of healthy controls. As a variety of diagnostic definitions of endogenous depression have been proposed, probands and relatives were diagnosed in a polydiagnostic manner. None of the five diagnostic definitions of endogeno…
Special Issue on “Proteostasis and Autophagy”
2019
Autophagy is a highly conserved eukaryotic pathway responsible for the lysosomal degradation (and subsequent recycling) of cellular components such as proteins, protein aggregates, and a growing number of organelles or cellular compartments [...]
The Cleavage Product of Amyloid-β Protein Precursor sAβPPα Modulates BAG3-Dependent Aggresome Formation and Enhances Cellular Proteasomal Activity
2015
Alzheimer's disease (AD) is the major age-associated form of dementia characterized by gradual cognitive decline. Aberrant cleavage of the amyloid-β protein precursor (AβPP) is thought to play an important role in the pathology of this disease. Two principal AβPP processing pathways exist: amyloidogenic cleavage of AβPP resulting in production of the soluble N-terminal fragment sAβPPβ, amyloid-β (Aβ), which accumulates in AD brain, and the AβPP intracellular domain (AICD) sAβPPα, p3 and AICD are generated in the non-amyloidogenic pathway. Prevalence of amyloidogenic versus non-amyloidogenic processing leads to depletion of sAβPPα and an increase in Aβ. Although sAβPPα is a well-accepted neu…
Aggregation Kinetics of Bovine Serum Albumin Studied by FTIR Spectroscopy and Light Scattering
2003
To investigate which type of structural and conformational changes is involved in the aggregation processes of bovine serum albumin (BSA), we have performed thermal aggregation kinetics in D(2)O solutions of this protein. The tertiary conformational changes are followed by Amide II band, the secondary structural changes and the formation of beta-aggregates by the Amide I' band and, finally, the hydrodynamic radius of aggregates by dynamic light scattering. The results show, as a function of pD, that: tertiary conformational changes are more rapid as pD increases; the aggregation proceeds through formation of ordered aggregates (oligomers) at pD far from the isoelectric point of the protein;…
Conformational changes involved in thermal aggregation processes of bovine serum albumin
2003
We report a kinetic study on thermal aggregation process of the model protein bovine serum albumin (BSA) in low concentration regime. Aim of this study is to provide information on relationship between conformational changes and initial step of aggregation. The experimental approach is based on steady-state fluorescence spectra of the two tryptophans located in two different domains, in way to study conformational changes in the surrounding of these residues. We also follow emission spectra of Fluorescein-5-Maleimide dye bound to the single free cysteine of BSA. Complementary information on the extent of aggregation and on the structural changes is obtained by Rayleigh scattering and circul…
Thermal aggregation of beta-lactoglobulin in presence of metal ions.
2007
In this work, we report a study of the effects of zinc and copper ions on the heat-induced aggregation of beta-lactoglobulin (BLG). Kinetics investigations on aggregates growth by light scattering measurements and on secondary structure changes by FTIR absorption measurements show the different role played by the two metals during the whole process. In particular, the presence of zinc in solution promotes the formation of aggregates of BLG at a lower temperature than copper. Then, at fixed temperature, formation of a large amount of aggregates, of large dimension, is observed for Zn-BLG in shorter time; on the contrary, the presence of copper in solution does not affect the aggregation proc…
Wild-type Cu/Zn superoxide dismutase (SOD1) does not facilitate, but impedes the formation of protein aggregates of amyotrophic lateral sclerosis cau…
2009
Aggregation of Cu/Zn superoxide dismutase (SOD1) is a hallmark of a subset of familial amyotrophic lateral sclerosis (ALS) cases. The expression of wild-type SOD1 [SOD(hWT)] surprisingly exacerbates the phenotype of mutant SOD1 in vivo. Here we studied whether SOD1(hWT) may affect mutant SOD1 aggregation by employing fluorescence microscopy techniques combined with lifetime-based Förster resonance energy transfer (FRET). Only a very minor fraction of SOD1(hWT) was observed in aggregates induced by mutant SOD1(G37R), SOD1(G85R) or SOD1(G93C). Quite in contrast, co-expression of SOD(hWT) reduced the amount of mutant SOD1 in the aggregate fraction. Furthermore, we did not detect endogenous mou…
Thioflavin T templates amyloid β(1–40) conformation and aggregation pathway
2015
Aβ(1-40) peptide supramolecular assembly and fibril formation processes are widely recognized to have direct implications in the progression of Alzheimer's disease. The molecular basis of this biological process is still unknown and there is a strong need of developing effective strategies to control the occurring events. To this purpose the exploitation of small molecules interacting with Aβ aggregation represents one of the possible routes. Moreover, the use specific labeling has represented so far one of the most common and effective methods to investigate such a process. This possibility in turn rests on the reliability of the probe/labels involved. Here we present evidences of the effe…
Influence of metal ions on thermal aggregation processes of globular proteins
2010
Metal ions are implicated in protein aggregation processes of several neurodegenerative pathologies, where the protein deposition occurs. The idea arises from the finding that increased metal concentrations (mainly copper, iron and zinc) are present in the brains of Alzheimer's disease patients both in the amyloid plaques and in the cortical tissue. Cu2+ and Zn2+ metals ions have a different physiological role and it has been observed that, in vitro, both promote (zinc more than copper) aggregation in amyloid fibrils and/or in amorphous aggregates. In addition, studying aggregation protein process can be of interest also in the field of biotechnologies like the food technology, since most p…