The process of insulin aggregation in neutral solutions was studied by dynamic light scattering. Solutions of different concentrations were subjected to thermal and mechanical stress (37 degrees, rotation) for a period of 4 weeks. The starting solutions contained exclusively one particle distribution of insulin in the association equilibrium with hexamers as the largest structures. After a lag period of about 8 days the solutions showed continuously increasing scattering intensities but did not evolve perceptible turbidity within the experimental period. A more rapid increase in scattering intensity was observed in diluted than in concentrated solutions. The analysis of scattering data unexpectedly revealed that insulin species did not grow continuously. After the lag period one additional relatively restricted size distribution with particles of a mean radius of about 100 nm was found, the amount of which increased continuously with time. The occurrence of these particles seems to be related to adsorption phenomena of insulin to the solid interface. We assume the 100 nm-class of aggregates to be a transient state in the physical destabilization process of insulin solutions.
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http://dx.doi.org/10.1111/j.1399-3011.1990.tb01292.x | DOI Listing |
Int J Mol Sci
December 2024
Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Lipopolysaccharides (LPS) are bacterial mediators of neuroinflammation that have been detected in close association with pathological protein aggregations of Alzheimer's disease. LPS induce the release of cytokines by microglia and mediate the upregulation of inducible nitric oxide synthase (iNOS)-a mechanism also associated with amyloidosis. Curcumin is a recognized natural medicine but has extremely low bioavailability.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark; Center for Biopharmaceuticals and Biobarriers in Drug Delivery, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark. Electronic address:
Ion-protein interactions regulate biological processes and are the basis of key strategies of modulating protein phase diagrams and stability in drug development. Here, we report the mechanisms by which H-bonds and electrostatic interactions in ion-protein systems determine phase separation and amyloid formation. Using microscopy, small-angle X-ray scattering, circular dichroism and atomistic molecular dynamics (MD) simulations, we found that anions specifically interacting with insulin induced phase separation by neutralising the protein charge and forming H-bond bridges between insulin molecules.
View Article and Find Full Text PDFBackground: Existing cohort studies show no association between insulin use and cancers of the digestive system, while numerous meta-analyses suggest that insulin use increases the risk of digestive system tumours. This study uses two-sample Mendelian randomization (MR) to further investigate the causal relationship between the two.
Methods: We selected single nucleotide polymorphisms (SNPs) strongly associated with insulin use as instrumental variables and used aggregated statistics on digestive system neoplasms as the outcome event.
Children (Basel)
December 2024
Department of Pediatrics, Federal University of Paraná, Curitiba 80060-000, PR, Brazil.
Background/objectives: The associations between low birth weight (LBW) and the aggregation of metabolic risk factors (MRF) in youth remain ambiguous. Thus, this study analysed the interrelationship among MRF, LBW, and behavioural factors in adolescents.
Methods: The sample of the present cross-sectional study comprised 491 youth (229 males, 262 females) aged 14-17 years.
Biomedicines
December 2024
Research Unit of Psychiatry, Department of Psychiatry, Odense, Region of Southern Denmark, University Hospital of Southern Denmark, 5000 Odense, Denmark.
Despite many years of research into the complex neurobiology of Parkinson's disease, the precise aetiology cannot be pinpointed down to one causative agent but rather a multitude of mechanisms. Current treatment options can alleviate symptomsbut only slightly slow down the progression and not cure the disease and its underlying causes. Factors that play a role in causing the debilitating neurodegenerative psycho-motoric symptoms include genetic alterations, oxidative stress, neuroinflammation, general inflammation, neurotoxins, iron toxicity, environmental influences, and mitochondrial dysfunction.
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