Expression, Characterization and Synergistic Interactions of Myxobacter Sp. AL-1 Cel9 and Cel48 Glycosyl Hydrolases

International Journal of Molecular Sciences

Norma Ramírez-Ramírez¹  Eliel R. Romero-Garc໚¹  Vianney C. Calderón¹  Claudia I. Avitia¹  Alfredo Téllez-Valencia² 

[1] Instituto de Investigación en Biología Experimental (IIBE), Facultad de Química, Universidad de Guanajuato. P.O. Box 187. Guanajuato, Gto. 36050, Mexico.;Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo. Abasolo 600, Pachuca, Hgo. 42000, Mexico

关键词: Cellulose;    Cel9;    Cel48 cellulases;    Synergism;    Myxobacter Sp. AL-1;   

DOI  :  10.3390/ijms9030247

来源: mdpi

【 摘 要 】

The soil microorganism Myxobacter Sp. AL-1 regulates in a differential manner the production of five extracellular cellulases during its life cycle. The nucleotide sequence of a cel9-cel48 cluster from the genome of this microorganism was recently obtained. Cel48 was expressed in Escherichia coli to generate a His₆-Cel48 protein and the biochemical properties of the pure protein were determined. Cel48 was more efficient in degrading acid-swollen avicel (ASC) than carboxymethylcellulose (CMC). On the other hand, cel9 was expressed in Bacillus subtilis from an IPTG-inducible promoter. Zymogram analysis showed that after IPTG-induction, Cel9 existed in both the cell fraction and the culture medium of B. subtilis and the secreted protein was purified to homogeneity by FPLC-ionic exchange chromatography. The exocellobiohydrolase Cel48 showed a synergism of 1.68 times with the endocellulase Cel9 during ASC degradation using an 8.1-fold excess of Cel48 over Cel9. Western blot analysis revealed that both proteins were synthesized and secreted to the culture medium of Myxobacter Sp. AL-1. These results show that the cel9-cel48 cluster encodes functional endo- and exo-acting cellulases that allows Myobacter Sp. AL-1 to hydrolyse cellulose.

【 授权许可】

CC BY   
© 2008 by MDPI