KnowVolution of a Fungal Laccase toward Alkaline pH.
Chembiochem
; 20(11): 1458-1466, 2019 06 03.
Article
em En
| MEDLINE
| ID: mdl-30702209
ABSTRACT
To date, commercial laccase preparations are used in the food, textile, and paper and pulp industries (mild pH). Laccases are attractive in the synthesis of dye molecules or oxidative lignin treatment, which take place at high pH (≥8.0). So far, one fungal laccase has been reported to be active at alkaline pH. Herein, engineering of the fungal laccase from Melanocarpus albomyces (MaL) for increased activity toward the substrate 2,6-dimethoxyphenol at pH (≥9.0) is reported. Through a knowledge-gaining directed evolution (KnowVolution) campaign, the key positions Leu365 and Leu513 were identified to increase alkaline tolerance. Both positions are located in close proximity of the T1Cu site. Molecular docking and simulations studies reveal that both substitutions act in a synergic way to stabilize and improve laccase activity at higher pH. Kinetic characterization of the final variant MaL-M1 (L365E/L513M) revealed at pHâ
9.8 a threefold improved kcat (kcat =(6.0±0.2)â
s-1 ) compared with that of wild-type M.â
albomyces laccase (kcat =(2.11±0.07)â
s-1 ).
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Fúngicas
/
Sordariales
/
Lacase
Idioma:
En
Revista:
Chembiochem
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Alemanha