Molecular Dynamics of Amylin Amyloid Single Beta-Sheet
2011
Dmitrijs Lapidus, Salvador Ventura, Cezary Czaplewsky, Adam Liwo, Inta Liepina

Amyloidosis are metabolic conformational diseases caused by misfolding and aggregation of soluble proteins in insoluble fibrils which deposit squeezing out the functioning cells or block cell-to-cell connectivity. Amylin or Islet Amyloid Polypeptide (IAPP) is a 37 residue peptide hormone secreted by pancreatic β-cells together with insulin. Amylin forms deposits in pancreas and is a non-insulin-dependent type II diabetes disease agent. Six stranded single ß-sheets of amylin 10-29 residues QRLANFLVHSSNNFGAILSS (Amylin 10-29), was investigated by molecular dynamics (MD) simulations in a periodic box using Amber 9.0, f99 force field and isothermal-isobaric ensemble, NTP protocol (constant temperature, pressure and the number of particles). The total MD run was 193 ns for Amylin 10-29. MD simulations show that a) Amylin 10-29 ß-sheet is bound together mainly by backbone hydrogen bonding, b) The ß-sheet is stabilized by side chain hydrogen bonding between asparagine residues and between residues Ser20 and Asp22 c). The ß-strands of Amylin 10-29 are glued together by leucine, isoleucine, valine residues and by phenylalanine residues, which together with asparagine residues form a sub-stack kept together by mild polar interactions, d) The C terminal part of the Amylin 10-29 ß-sheet has the hydrophobic anchor of isoleucine and leucine residues Ile26-Leu27 which could be used to bind nearby ß-sheets in the ß-sheet protofibril. This binding should stabilize the ß-structure of a separate ß-sheet. e). In the Amylin 10-29 region Ser19-Ser20-Asn21-Asn22 the ß-sheet has the W-shaped bend with the deeper vertex on Ser20 and smaller vertex on Asn22, suggesting that also the bent ß-sheet could be possible.


Atslēgas vārdi
Amylin, amyloidosis, molecular dynamics, beta-sheet.

Lapidus, D., Ventura, S., Czaplewsky, C., Liwo, A., Liepina, I. Molecular Dynamics of Amylin Amyloid Single Beta-Sheet. Materiālzinātne un lietišķā ķīmija . Nr.23, 2011, 49.-55.lpp. ISSN 1407-7353.

Publikācijas valoda
English (en)
RTU Zinātniskā bibliotēka.
E-pasts: uzzinas@rtu.lv; Tālr: +371 28399196