Structural dynamic of a self-assembling peptide d-EAK16 made of only D-amino acids
| Autor: | Xiaojun Zhao, Shuguang Zhang, Zhongli Luo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Models
Molecular Circular dichroism Protein Denaturation Hot Temperature Molecular Sequence Data Biochemistry/Biomimetic Chemistry lcsh:Medicine Peptide Microscopy Atomic Force Biochemistry Protein structure Biochemistry/Protein Chemistry Biochemistry/Macromolecular Chemistry Amino Acid Sequence Amino Acids lcsh:Science Peptide sequence Protein secondary structure chemistry.chemical_classification Multidisciplinary Chemistry Circular Dichroism Osmolar Concentration lcsh:R Stereoisomerism Hydrogen-Ion Concentration Amino acid Crystallography Ionic strength lcsh:Q Oligopeptides Self-assembling peptide Research Article |
| Zdroj: | PLoS ONE, Vol 3, Iss 5, p e2364 (2008) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | We here report systematic study of structural dynamics of a 16-residue self-assembling peptide d-EAK16 made of only D-amino acids. We compare these results with its chiral counterpart L-form, l-EAK16. Circular dichroism was used to follow the structural dynamics under various temperature and pH conditions. At 25 degrees C the d-EAK16 peptide displayed a typical beta-sheet spectrum. Upon increasing the temperature above 70 degrees C, there was a spectrum shift as the 218 nm valley widens toward 210 nm. Above 80 degrees C, the d-EAK16 peptide transformed into a typical alpha-helix CD spectrum without going through a detectable random-coil intermediate. When increasing the temperature from 4 degrees C to 110 degrees C then cooling back from 110 degrees C to 4 degrees C, there was a hysteresis: the secondary structure from beta-sheet to alpha-helix and then from alpha-helix to beta-sheet occurred. d-EAK16 formed an alpha-helical conformation at pH0.76 and pH12 but formed a beta-sheet at neutral pH. The effects of various pH conditions, ionic strength and denaturing agents were also noted. Since D-form peptides are resistant to natural enzyme degradation, such drastic structural changes may be exploited for fabricating molecular sensors to detect minute environmental changes. This provides insight into the behaviors of self-assembling peptides made of D-amino acids and points the way to designing new peptide materials for biomedical engineering and nanobiotechnology. |
| Databáze: | OpenAIRE |
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