A conserved π-cation and an electrostatic bridge are essential for 11R-lipoxygenase catalysis and structural stability.
Biochim Biophys Acta
; 1851(10): 1377-82, 2015 Oct.
Article
em En
| MEDLINE
| ID: mdl-26215075
ABSTRACT
Lipoxygenases (LOXs) are lipid-peroxidizing enzymes that consist of a regulatory calcium- and membrane-binding PLAT (polycystin-1, lipoxygenase, α-toxin) domain and a catalytic domain. In a previous study, the crystal structure of an 11R-LOX revealed a conserved π-cation bridge connecting these two domains which could mediate the regulatory effect of the PLAT domain to the active site. Here we analyzed the role of residues Trp107 and Lys172 that constitute the π-cation bridge in 11R-LOX along with Arg106 and Asp173-a potential salt bridge, which could also contribute to the inter-domain communication. According to our kinetic assays and protein unfolding experiments conducted using differential scanning fluorimetry and circular dichroism spectroscopy, mutants with a disrupted link display diminished catalytic activity alongside reduced stability of the protein fold. The results demonstrate that both these bridges contribute to the two-domain interface, and are important for proper enzyme activation.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lipoxigenase
/
Dobramento de Proteína
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Antozoários
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article