Structural and functional analyses of an L-asparaginase from Geobacillus thermopakistaniensis.
Int J Biol Macromol
; 263(Pt 2): 130438, 2024 Apr.
Article
em En
| MEDLINE
| ID: mdl-38408579
ABSTRACT
Genome sequence of Geobacillus thermopakistaniensis contains an open reading frame annotated as a type II L-asparaginase (ASNaseGt). Critical structural analysis disclosed that ASNaseGt might be a type I L-asparaginase. In order to determine whether it is a type I or type II L-asparaginase, we have performed the structural-functional characterization of the recombinant protein as well as analyzed the localization of ASNaseGt in G. thermopakistaniensis. ASNaseGt exhibited optimal activity at 52 °C and pH 9.5. There was a > 3-fold increase in activity in the presence of ß-mercaptoethanol. Apparent Vmax and Km values were 2735 U/mg and 0.35 mM, respectively. ASNaseGt displayed high thermostability with >80 % residual activity even after 6 h of incubation at 55 °C. Recombinant ASNaseGt existed in oligomeric form. Addition of ß-mercaptoethanol lowered the degree of oligomerization and displayed that tetrameric form was the most active, with a specific activity of 4300 U/mg. Under physiological conditions, ASNaseGt displayed >50 % of the optimal activity. Localization studies in G. thermopakistaniensis revealed that ASNaseGt is a cytosolic protein. Structural and functional characterization, and localization in G. thermopakistaniensis displayed that ASNaseGt is not a type II but a type I L-asparaginase.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Asparaginase
/
Geobacillus
Idioma:
En
Revista:
Int J Biol Macromol
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Paquistão
País de publicação:
Holanda