Purification and characterization of a periplasmic laccase produced by Sinorhizobium meliloti
| Autor: | Laura Franco Fraguas, Susana Castro-Sowinski, Federico Rosconi, Gloria Martinez-Drets |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
chemistry.chemical_classification
Laccase Sinorhizobium meliloti Chromatography biology Molecular mass Active site Substrate (chemistry) Bioengineering Periplasmic space biology.organism_classification Applied Microbiology and Biotechnology Biochemistry Enzyme Isoelectric point chemistry biology.protein Biotechnology Nuclear chemistry |
| Zdroj: | Enzyme and Microbial Technology. 36:800-807 |
| ISSN: | 0141-0229 |
| DOI: | 10.1016/j.enzmictec.2005.01.003 |
| Popis: | Sinorhizobium meliloti CE52G strain produces a periplasmic laccase that has been purified by a two-step procedure involving heat treatment and immobilized metal affinity chromatography (IMAC). The fraction with laccase activity retained its original activity after 24 h of incubation at pH between 4.0 and 8.0 and after 3 h of incubation at 70 °C, pH 7.2 and supplemented with 1.3 M (NH 4 ) 2 SO 4 . It proved to be a homodimeric protein with an apparent molecular mass of 45 kDa each subunit and an isoelectric point of 6.2. CE52G laccase was inhibited by halides (NaF and NaCl), ions (Fe 3+ , Mn 2+ , and Cu 2+ ), sulfhydryl organic compounds (β-mercaptoethanol and reduced glutathione), and electron flow inhibitors (NaCN and NaF). Laccase activity was strongly enhanced by (NH 4 ) 2 SO 4 , Na 2 SO 4 , and K 2 SO 4 . The effects of all these agents, as well as the probability of a partially unfolding polypeptide chain to enhance the interaction between the substrate and the active site, are discussed. CE52G laccase is a pH- and thermo-stable protein with promising biotechnological applications. |
| Databáze: | OpenAIRE |
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