Calcium Regulates S100A12 Zinc Sequestration by Limiting Structural Variations.
Chembiochem
; 21(9): 1372-1382, 2020 05 04.
Article
em En
| MEDLINE
| ID: mdl-31821694
ABSTRACT
Antimicrobial proteins such as S100A12 and S100A8/A9 are highly expressed and secreted by neutrophils during infection and participate in human immune response by sequestering transition metals. At neutral pH, S100A12 sequesters Zn2+ with nanomolar affinity, which is further enhanced upon calcium binding. We investigated the pH dependence of human S100A12 zinc sequestration by using Co2+ as a surrogate. Apo-S100A12 exhibits strong Co2+ binding between pHâ
7.0 and 10.0 that progressively diminishes as the pH is decreased to 5.3. Ca2+ -S100A12 can retain nanomolar Co2+ binding up to pHâ
5.7. NMR spectroscopic measurements revealed that calcium binding does not alter the side-chain protonation of the Co2+ /Zn2+ binding histidine residues. Instead, the calcium-mediated modulation is achieved by restraining pH-dependent conformational changes to EF loopâ
1, which contains Co2+ /Zn2+ binding Asp25. This calcium-induced enhancement of Co2+ /Zn2+ binding might assist in the promotion of antimicrobial activities in humans by S100 proteins during neutrophil activation under subneutral pH conditions.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Zinco
/
Cálcio
/
Cobalto
/
Proteína S100A12
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article