Human Islet Amyloid Polypeptide N-Terminus Fragment Self-Assembly: Effect of Conserved Disulfide Bond on Aggregation Propensity

2016 ◽  
Vol 27 (6) ◽  
pp. 1010-1018 ◽  
Author(s):  
Alexandre I. Ilitchev ◽  
Maxwell J. Giammona ◽  
Thanh D. Do ◽  
Amy G. Wong ◽  
Steven K. Buratto ◽  
...  
Keyword(s):  
Disulfide Bond ◽  
Self Assembly ◽  
Islet Amyloid Polypeptide ◽  
Human Islet ◽  
Islet Amyloid ◽  
Aggregation Propensity ◽  
Human Islet Amyloid Polypeptide ◽  
N Terminus

scholarly journals Human islet amyloid polypeptide at the air–aqueous interface: a Langmuir monolayer approach

2012 ◽  
Vol 9 (76) ◽  
pp. 3118-3128 ◽  
Author(s):  
Shanghao Li ◽  
Miodrag Micic ◽  
Jhony Orbulescu ◽  
Jeffrey D. Whyte ◽  
Roger M. Leblanc
Keyword(s):  
Self Assembly ◽  
Islet Amyloid Polypeptide ◽  
Langmuir Monolayer ◽  
Human Islet ◽  
Diabetic Patients ◽  
Brewster Angle Microscopy ◽  
Islet Amyloid ◽  
Type 2 Diabetic Patients ◽  
Human Islet Amyloid Polypeptide ◽  
Time Zero

Human islet amyloid polypeptide (hIAPP) is the source of the major component of the amyloid deposits found in the islets of Langerhans of around 95 per cent type 2 diabetic patients. The formation of aggregates and mature fibrils is thought to be responsible for the dysfunction and death of the insulin-producing pancreatic β-cells. Investigation on the conformation, orientation and self-assembly of the hIAPP at time zero could be beneficial for our understanding of its stability and aggregation process. To obtain these insights, the hIAPP at time zero was studied at the air–aqueous interface using the Langmuir monolayer technique. The properties of the hIAPP Langmuir monolayer at the air–aqueous interface on a NaCl subphase with pH 2.0, 5.6 and 9.0 were examined by surface pressure- and potential-area isotherms, UV–Vis absorption, fluorescence spectroscopy and Brewster angle microscopy. The conformational and orientational changes of the hIAPP Langmuir monolayer under different surface pressures were characterized by p-polarized infrared-reflection absorption spectroscopy, and the results did not show any prominent changes of conformation or orientation. The predominant secondary structure of the hIAPP at the air–aqueous interface was α-helix conformation, with a parallel orientation to the interface during compression. These results showed that the hIAPP Langmuir monolayer at the air–aqueous interface was stable, and no aggregate or domain of the hIAPP at the air–aqueous interface was observed during the time of experiments.

Myricetin protects pancreatic β-cells from human islet amyloid polypeptide (hIAPP) induced cytotoxicity and restores islet function

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Richa Dubey ◽  
Shruti H. Kulkarni ◽  
Sarath Chandra Dantu ◽  
Rajlaxmi Panigrahi ◽  
Devika M. Sardesai ◽  
...  
Keyword(s):  
Stress Reduction ◽  
Self Assembly ◽  
Membrane Damage ◽  
Islet Amyloid Polypeptide ◽  
Human Islet ◽  
Dynamics Simulation ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide

AbstractThe aberrant misfolding and self-assembly of human islet amyloid polypeptide (hIAPP)–a hormone that is co-secreted with insulin from pancreatic β-cells–into toxic oligomers, protofibrils and fibrils has been observed in type 2 diabetes mellitus (T2DM). The formation of these insoluble aggregates has been linked with the death and dysfunction of β-cells. Therefore, hIAPP aggregation has been identified as a therapeutic target for T2DM management. Several natural products are now being investigated for their potential to inhibit hIAPP aggregation and/or disaggregate preformed aggregates. In this study, we attempt to identify the anti-amyloidogenic potential of Myricetin (MYR)- a polyphenolic flavanoid, commonly found in fruits (like Syzygium cumini). Our results from biophysical studies indicated that MYR supplementation inhibits hIAPP aggregation and disaggregates preformed fibrils into non-toxic species. This protection was accompanied by inhibition of oxidative stress, reduction in lipid peroxidation and the associated membrane damage and restoration of mitochondrial membrane potential in INS-1E cells. MYR supplementation also reversed the loss of functionality in hIAPP exposed pancreatic islets via restoration of glucose-stimulated insulin secretion. Molecular dynamics simulation studies suggested that MYR molecules interact with the hIAPP pentameric fibril model at the amyloidogenic core region and thus prevents aggregation and distort the fibrils.

scholarly journals The Curli Accessory Protein CsgF Influences the Aggregation of Human Islet Amyloid Polypeptide

2019 ◽  
Author(s):  
Osmar Meza-Barajas ◽  
Isamar Aranda ◽  
Ashwag Binmahfooz ◽  
Alliosn Newell ◽  
Sajith Jayasinghe
Keyword(s):  
Cell Surface ◽  
Structural Changes ◽  
Islet Amyloid Polypeptide ◽  
Human Islet ◽  
Major Protein ◽  
Solvent Exposure ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide ◽  
N Terminus ◽  
The Individual

AbstractGram-negative bacteria, such as E. coli and Salmonella, contain proteinaceous, hair-like, cell surface filaments known as curli. Curli serve to facilitate cell-cell interactions and are essential for host cell colonization. Curli assembly involves six proteins, CsgA, CsgB, CsgC, CsgE, CsgF, and CsgG. CsgE and CsgF are thought to act as chaperones to help prevent the premature aggregation of CsgA and/or CsgB, and to help transport these proteins, through the outer-membrane protein CsgG, to the cell surface where they assemble to form Curli. It has been observed that CsgF is able to inhibit the aggregation of CsgA, the major protein component of Curli. This article describes CsgF’s ability to influence the aggregation of human islet amyloid polypeptide (hIAPP), an amyloidogenic polypeptide that is unrelated to Curli. In the presence of CsgF no increase in Thioflavin T fluorescence was observed for freshly solubilized hIAPP monitored as a function of time, suggesting that CsgF prevents the aggregation of hIAPP during the time period of observation. An analog of CsgF lacking the N-terminal unstructured region retained the ability to inhibit the aggregation of hIAPP. The nature of the CsgF-hIAPP interaction was probed via fluorescence quenching using a series of single cysteine mutants of CsgF labeled via the individual cysteine side chains with the fluorophore IAEDANS. In the presence of hIAPP, but not in the presence of the non-amyloidogenic rat islet amyloid polypeptide, the fluorophore attached to position of 23 of CsgF was found to be less exposed the quencher acrylamide suggesting that the interaction of hIAPP changes the solvent exposure of the N-terminus of CsgF. Taken together these data suggest that the structured region of CsgF, between residues 66 and 128, is involved in the protein’s interaction with hIAPP and that upon interaction structural changes make the N-terminus less solvent exposed.

Human islet amyloid polypeptide accumulates at similar sites in islets of transgenic mice and humans

Diabetes ◽  
1994 ◽  
Vol 43 (5) ◽  
pp. 640-644 ◽  
Author(s):  
E. J. de Koning ◽  
J. W. Hoppener ◽  
J. S. Verbeek ◽  
C. Oosterwijk ◽  
K. L. van Hulst ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Islet Amyloid Polypeptide ◽  
Human Islet ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide

scholarly journals The flanking peptides issue from the maturation of the human islet amyloid polypeptide (hIAPP) slightly modulate hIAPP-fibril formation but not hIAPP-induced cell death

Biochimie ◽  
2020 ◽  
Vol 170 ◽  
pp. 26-35 ◽  
Author(s):  
Shadai Salazar Vazquez ◽  
Bertrand Blondeau ◽  
Pierre Cattan ◽  
Mathieu Armanet ◽  
Ghislaine Guillemain ◽  
...  
Keyword(s):  
Cell Death ◽  
Islet Amyloid Polypeptide ◽  
Fibril Formation ◽  
Human Islet ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide

scholarly journals Regulation of divalent metal ions to the aggregation and membrane damage of human islet amyloid polypeptide oligomers

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12815-12825
Author(s):  
Yajie Wang ◽  
Feihong Meng ◽  
Tong Lu ◽  
Chunyun Wang ◽  
Fei Li
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Membrane Damage ◽  
Islet Amyloid Polypeptide ◽  
Divalent Metal ◽  
Human Islet ◽  
Divalent Metal Ions ◽  
Islet Amyloid ◽  
Induced Membrane ◽  
Human Islet Amyloid Polypeptide

Their is a counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the metal binding in the activity of hIAPP induced membrane damage.

scholarly journals Interactions of human islet amyloid polypeptide with lipid structure of different curvatures

2020 ◽  
Vol 10 (6) ◽  
pp. 412-418
Author(s):  
Le Mei ◽  
Wenhui Shen ◽  
Xuwei Wu ◽  
Jie Liu ◽  
Dechang Li ◽  
...  
Keyword(s):  
Islet Amyloid Polypeptide ◽  
Human Islet ◽  
Islet Amyloid ◽  
Lipid Structure ◽  
Human Islet Amyloid Polypeptide

scholarly journals Amyloidogenicity and Cytotoxicity of Recombinant Mature Human Islet Amyloid Polypeptide (rhIAPP)

2004 ◽  
Vol 279 (41) ◽  
pp. 42803-42810 ◽  
Author(s):  
Dahabada H. J. Lopes ◽  
Christian Colin ◽  
Theri L. Degaki ◽  
Ana Christina V. de Sousa ◽  
Marcelo N. N. Vieira ◽  
...  
Keyword(s):  
Islet Amyloid Polypeptide ◽  
Human Islet ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide
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