Biochemical Characterization of a Novel Thermostable 1,4-α-Glucoamylase from Aspergillus brasiliensis Strain Isolated in the Brazilian Atlantic Forest.
Appl Biochem Biotechnol
; 2024 Mar 21.
Article
em En
| MEDLINE
| ID: mdl-38512551
ABSTRACT
Glucoamylases are exo-enzymes that cleave the ends of the starch chain, releasing glucose units. In the current work, we described a novel 1,4-α-glucoamylase from an A. brasiliensis strain isolated from an environmental sample. The purified glucoamylase, GlaAb, has a molecular mass of 69 kDa and showed a starch binding domain. GlaAb showed a similar sequence to other fungal glucoamylases, and the molecular 3D model analysis of GlaAb suggests an overall structure as described in the literature, except by elongation in the loop connecting the 4th and 5th α-helices. The enzyme showed activity over a wide range of pH and temperature, with maximum activity at pH 4.5 and 60 °C. GlaAb was stable at 50 °C for 7 h, maintaining 67% residual activity, and it was not inhibited by glucose up to 0.1 M. The glucoamylase was 65% more active in the presence of Mn2+ and showed a Km of 2.21 mg mL-1, Vmax of 155 U mg-1, Kcat 179 s-1, and Kcat/Km 81.06 mg mL-1 s-1 using potato starch as substrate. The results obtained are promising and provide the basis for the development of applications of GlaAb in the industrial process.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Appl Biochem Biotechnol
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos