Inducing α-Helicity in Peptides by Silver Coordination to Cysteine.
Chemistry
; 30(31): e202304064, 2024 Jun 03.
Article
em En
| MEDLINE
| ID: mdl-38456607
ABSTRACT
Short peptide sequences consisting of two cysteine residues separated by three other amino acids display complete change from random coil to α-helical secondary structure in response to addition of Ag+ ions. The folded CXXXC/Ag+ complex involves formation of multinuclear Ag+ species and is stable in a wide pH range from below 3 to above 8. The complex is stable through reversed-phase HPLC separation as well as towards a physiological level of chloride ions, based on far-UV circular dichroism spectroscopy. In electrospray MS under acidic conditions a peptide dimer with four Ag+ ions bound was observed, and modelling based on potentiometric experiments supported this to be the dominating complex at neutral pH together with a peptide dimer with 3â
Ag+ and one proton at lower pH. The complex was demonstrated to work as a N-terminal nucleation site for inducing α-helicity into longer peptides. This type of silver-mediated peptide assembly and folding may be of more general use for stabilizing not only peptide folding but also for controlling oligomerization even under acidic conditions.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
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Prata
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Dicroísmo Circular
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Cisteína
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article