scholarly journals Pyroglutamate-modified Aβ(3-42) affects aggregation kinetics of Aβ(1-42) by accelerating primary and secondary pathways

2017 ◽  
Vol 8 (7) ◽  
pp. 4996-5004 ◽  
Author(s):  
C. Dammers ◽  
M. Schwarten ◽  
A. K. Buell ◽  
D. Willbold
Keyword(s):  
Amyloid Β ◽  
Full Length ◽  
Aggregation Kinetics ◽  
Individual Reaction ◽  
Kinetics Of

Fibrillary and monomeric pyroglutamate-modified amyloid-β(3-42) accelerates all individual reaction steps of full-length amyloid-β(1-42) and act as a subsequent seeding species.

Using Small Peptide Segments of Amyloid-β and Humanin to Examine their Physical Interactions

2019 ◽  
Vol 26 (7) ◽  
pp. 502-511 ◽  
Author(s):  
Deborah L. Heyl ◽  
Brandon Iwaniec ◽  
Daniel Esckilsen ◽  
Deanna Price ◽  
Prathyusha Guttikonda ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amyloid Fibrils ◽  
Amyloid Β ◽  
Full Length ◽  
Binding Kinetics ◽  
Amino Acid Residues ◽  
Aβ Peptides ◽  
Physical Interactions ◽  
Peptide Segments ◽  
Kinetics Of

Background: Amyloid fibrils in Alzheimer’s disease are composed of amyloid-β (Aβ) peptides of variant lengths. Humanin (HN), a 24 amino acid residue neuroprotective peptide, is known to interact with the predominant Aβ isoform in the brain, Aβ (1-40). Methods: Here, we constructed smaller segments of Aβ and HN and identified residues in HN important for both HN-HN and HN-Aβ interactions. Peptides corresponding to amino acid residues 5- 15 of HN, HN (5-15), HN (5-15, L11S), where Leu11 was replaced with Ser, and residues 17-28 of Aβ, Aβ (17-28), were synthesized and tested for their ability to block formation of the complex between HN and Aβ (1-40). Results: Co-immunoprecipitation and binding kinetics showed that HN (5-15) was more efficient at blocking the complex between HN and Aβ (1-40) than either HN (5-15, L11S) or Aβ (17-28). Binding kinetics of these smaller peptides with either full-length HN or Aβ (1-40) showed that HN (5- 15) was able to bind either Aβ (1-40) or HN more efficiently than HN (5-15, L11S) or Aβ (17-28). Compared to full-length HN, however, HN (5-15) bound Aβ (1-40) with a weaker affinity suggesting that while HN (5-15) binds Aβ, other residues in the full length HN peptide are necessary for maximum interactions. Conclusion: L11 was more important for interactions with Aβ (1-40) than with HN. Aβ (17-28) was relatively ineffective at binding to either Aβ (1-40) or HN. Moreover, HN, and the smaller HN (5-15), HN (5-15 L11S), and Aβ (17-28) peptides, had different effects on regulating Aβ (1-40) aggregation kinetics.

scholarly journals Apolipoprotein E interacts with amyloid-β oligomers via positively cooperative multivalent binding

2018 ◽  
Author(s):  
S. Ghosh ◽  
T. B. Sil ◽  
S. Dolai ◽  
K. Garai
Keyword(s):  
Apolipoprotein E ◽  
Amyloid Β ◽  
Resonance Energy ◽  
Full Length ◽  
Aβ Oligomers ◽  
Critical Determinant ◽  
Competitive Binding Assay ◽  
Terminal Fragment ◽  
Multivalent Binding ◽  
Kinetics Of

AbstractInteraction of apolipoprotein E (apoE) isoforms with amyloid-β (Aβ) peptides is considered a critical determinant of the progression of Alzheimer’s disease. However, molecular mechanism of the apoE-Aβ interaction is poorly understood. Here we characterize the nature of the apoE-Aβ complexes and identify the region of apoE that interacts with Aβ. We have prepared three distinct fragments of apoE4, viz., the N-terminal fragment (NTF), hinge domain fragment (HDF) and C-terminal fragment (CTF) to compare its interactions with Aβ. Kinetics of aggregation of Aβ is delayed dramatically in presence of low, substoichiometric concentrations of both NTF and CTF in lipid-free, as well as, in lipidated forms. Effect of HDF is found to be small. Strong inhibition by NTF and CTF at substoichiometric concentrations indicate interactions with the ‘intermediates’ or the oligomers of Aβ. Kinetics of Forster Resonance Energy Transfer (FRET) between full-length apoE4 labeled with EDANS at positions 62, 139, 210, 247, and 276 and tetramethylrhodamine (TMR)-labeled Aβ further support involvement of multiple regions of apoE in the interactions. Since the interactions involve intermediates of Aβ quantitative evaluation of the binding affinities are not feasible. Hence we employed a competitive binding assay to examine whether the N- and C-terminal domains interact cooperatively. Addition of unlabeled full-length apoE eliminates the FRET between EDANS-NTF + EDANS-CTF and TMR-Aβ almost completely but not vice versa. Furthermore, full-length apoE but not the equimolar mixture of the fragments could displace the already bound EDANS-apoE molecules from the complexes. Therefore, binding affinity of the Aβ oligomers to the intact full-length apoE is much higher than the affinity to the domains when mixed together as fragments. Thus, our results indicate that apoE-Aβ complex formation is mediated by positively cooperative multivalent binding between the multiple sites on apoE and the oligomeric forms of Aβ.

Functional Fractionation of Platelets: Aggregation Kinetics and Glycoprotein Labeling of Differing Platelet Populations

1982 ◽  
Vol 48 (02) ◽  
pp. 211-216 ◽  
Author(s):  
V M Haver ◽  
A R L Gear
Keyword(s):  
Galactose Oxidase ◽  
Aggregation Kinetics ◽  
Maximal Rate ◽  
Membrane Glycoproteins ◽  
Whole Cells ◽  
Reversible Aggregation ◽  
Significant Difference ◽  
Small Doses ◽  
Major Loss ◽  
Kinetics Of

SummaryPlatelet heterogeneity has been studied with a technique called functional fractionation which employs gentle centrifugation to yield subpopulations (“reactive” and “less-reactive” platelets) after exposure to small doses of aggregating agent. Aggregation kinetics of the different platelet populations were investigated by quenched-flow aggregometry. The large, “reactive” platelets were more sensitive to ADP (Ka = 1.74 μM) than the smaller “less-reactive” platelets (Ka = 4.08 μM). However, their maximal rate of aggregation (Vmax, % of platelets aggregating per sec) of 23.3 was significantly lower than the “less-reactive” platelets (Vmax = 34.7). The “reactive” platelets had a 2.2 fold higher level of cyclic AMP.Platelet glycoproteins were labeled using the neuraminidase-galactose oxidase – [H3]-NaBH4 technique. When platelets were labeled after reversible aggregation, the “reactive” platelets showed a two-fold decrease in labeling efficiency (versus control platelets). However, examination of whole cells or membrane preparations from reversibly aggregated platelets revealed no significant difference in Coomassie or PAS (Schiff) staining.These results suggest that the large, “reactive” platelets are more sensitive to ADP but are not hyperaggregable in a kinetic sense. Reversible aggregation may cause a re-orientation of membrane glycoproteins that is apparently not characterized by a major loss of glycoprotein material.

scholarly journals Kinetics of amyloid β from deep learning

2021 ◽  
Vol 1 (1) ◽  
pp. 20-21
Author(s):  
Fanjie Meng ◽  
Hoi Sung Chung
Keyword(s):  
Deep Learning ◽  
Amyloid Β ◽  
Kinetics Of

Differential Influence of Amyloid-β on the Kinetics of Dopamine Release in the Dorsal and Ventral Striatum of Rats

2021 ◽  
Author(s):  
Valery N. Mukhin ◽  
Ivan R. Borovets ◽  
Vadim V. Sizov ◽  
Konstantin I. Pavlov ◽  
Victor M. Klimenko
Keyword(s):  
Dopamine Release ◽  
Ventral Striatum ◽  
Amyloid Β ◽  
Kinetics Of

scholarly journals Shear-induced reaction-limited aggregation kinetics of Brownian particles at arbitrary concentrations

2010 ◽  
Vol 132 (13) ◽  
pp. 134903 ◽  
Author(s):  
Alessio Zaccone ◽  
Daniele Gentili ◽  
Massimo Morbidelli
Keyword(s):  
Aggregation Kinetics ◽  
Brownian Particles ◽  
Kinetics Of ◽  
Induced Reaction

scholarly journals Thermodynamics and kinetics of the amyloid-β peptide revealed by Markov state models based on MD data in agreement with experiment

2021 ◽  
Author(s):  
Arghadwip Paul ◽  
Suman Samantray ◽  
Marco Anteghini ◽  
Mohammed Khaled ◽  
Birgit Strodel
Keyword(s):  
Amyloid Β ◽  
Md Simulations ◽  
Amyloid Β Peptide ◽  
Intrinsically Disordered ◽  
Thermodynamics And Kinetics ◽  
Markov State ◽  
Markov State Models ◽  
State Models ◽  
Kinetics Of

The convergence of MD simulations is tested using varying measures for the intrinsically disordered amyloid-β peptide (Aβ). Markov state models show that 20–30 μs of MD is needed to reliably reproduce the thermodynamics and kinetics of Aβ.

scholarly journals Rheological behaviour and aggregation kinetics of EG/water based MCNT nano-suspension for sub-zero temperature cold storage

2019 ◽  
Vol 158 ◽  
pp. 4846-4851
Author(s):  
Yaoting Huang ◽  
Chunping Xie ◽  
Chuan Li ◽  
Yongliang Li ◽  
Yulong Ding
Keyword(s):  
Cold Storage ◽  
Rheological Behaviour ◽  
Aggregation Kinetics ◽  
Zero Temperature ◽  
Water Based ◽  
Kinetics Of

The impact of stabilization mechanism on the aggregation kinetics of silver nanoparticles

2012 ◽  
Vol 429 ◽  
pp. 325-331 ◽  
Author(s):  
Amro M. El Badawy ◽  
Kirk G. Scheckel ◽  
Makram Suidan ◽  
Thabet Tolaymat
Keyword(s):  
Silver Nanoparticles ◽  
Aggregation Kinetics ◽  
Stabilization Mechanism ◽  
The Impact ◽  
Kinetics Of

scholarly journals The Conformation and the Aggregation Kinetics of α-Synuclein Depend on the Proline Residues in Its C-Terminal Region

Biochemistry ◽  
2010 ◽  
Vol 49 (43) ◽  
pp. 9345-9352 ◽  
Author(s):  
Jessika Meuvis ◽  
Melanie Gerard ◽  
Linda Desender ◽  
Veerle Baekelandt ◽  
Yves Engelborghs
Keyword(s):  
Terminal Region ◽  
Aggregation Kinetics ◽  
Kinetics Of
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