The reversible depletion and reconstitution of a copper ion in Coprinus cinereus laccase followed by spectroscopic techniques

Bukh, Christian; Bjerrum, Morten J.

doi:10.1016/j.jinorgbio.2010.05.010

Cited by 17 publications

(8 citation statements)

References 53 publications

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“…This high degree of glycosylation can explain why Mt L is highly soluble and could be concentrated to 120 mg ml -1 without any precipitation. Since purification and especially deglycosylation of laccases prior to crystallization often has been accompanied by loss of the labile T2-Cu [ 22 , 26 , 47 – 49 ], we aimed for crystallization of the fully glycosylated recombinant enzyme. A number of lead conditions were initially identified from sparse-matrix crystallization screening using commercial kits and a protein concentration of 100 mg ml -1 .…”

Section: Resultsmentioning

confidence: 99%

A comparative structural analysis of the surface properties of asco-laccases

et al. 2018

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Laccases of different biological origins have been widely investigated and these studies have elucidated fundamentals of the generic catalytic mechanism. However, other features such as surface properties and residues located away from the catalytic centres may also have impact on enzyme function. Here we present the crystal structure of laccase from Myceliophthora thermophila (MtL) to a resolution of 1.62 Å together with a thorough structural comparison with other members of the CAZy family AA1_3 that comprises fungal laccases from ascomycetes. The recombinant protein produced in A. oryzae has a molecular mass of 75 kDa, a pI of 4.2 and carries 13.5 kDa N-linked glycans. In the crystal, MtL forms a dimer with the phenolic substrate binding pocket blocked, suggesting that the active form of the enzyme is monomeric. Overall, the MtL structure conforms with the canonical fold of fungal laccases as well as the features specific for the asco-laccases. However, the structural comparisons also reveal significant variations within this taxonomic subgroup. Notable differences in the T1-Cu active site topology and polar motifs imply molecular evolution to serve different functional roles. Very few surface residues are conserved and it is noticeable that they encompass residues that interact with the N-glycans and/or are located at domain interfaces. The N-glycosylation sites are surprisingly conserved among asco-laccases and in most cases the glycan displays extensive interactions with the protein. In particular, the glycans at Asn88 and Asn210 appear to have evolved as an integral part of the asco-laccase structure. An uneven distribution of the carbohydrates around the enzyme give unique properties to a distinct part of the surface of the asco-laccases which may have implication for laccase function–in particular towards large substrates.

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Section: Resultsmentioning

confidence: 99%

A comparative structural analysis of the surface properties of asco-laccases

et al. 2018

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“…Laccases are sensitive towards metals, even at low concentrations and inhibit the laccase activity. Good induction of enzyme activity in the presence of CuSO 4 was due to the filling of type-2 copper-binding sites with copper ions and Cu 2+ being the main inducer for laccase [50], as the catalytic center of the enzyme contained Cu 2+ ions. Xin and Geng [51] also observed copper sulfateto be the best inducer for laccase production in Trametes versicolor.…”

Section: Discussionmentioning

confidence: 99%

Tree bark scrape fungus: A potential source of laccase for application in bioremediation of non-textile dyes

Sayyed

Bhamare²,

Sapna

et al. 2020

PLoS ONE

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Although laccase has been recognized as a wonder molecule and green enzyme, the use of low yielding fungal strains, poor production, purification, and low enzyme kinetics have hampered its large-scale application. Thus,this study aims to select high yielding fungal strains and optimize the production, purification, and kinetics of laccase of Aspergillus sp. HB_RZ4. The results obtained indicated that Aspergillus sp. HB_RZ4 produced a significantly large amount of laccase under meso-acidophilic shaking conditions in a medium containing glucose and yeast extract. A 25 μM CuSO 4 was observed to enhance the enzyme yield. The enzyme was best purified on a Sephadex G-100 column. The purified enzyme resembled laccase of A. flavus. The kinetics of the purified enzyme revealed high substrate specificity and good velocity of reaction,using ABTS as a substrate. The enzyme was observed to be stable over various pH values and temperatures. The peptide structure of the purified enzyme was found to resemble laccase of A. kawachii IFO 4308. The fungus was observed to decolorize various dyes independent of the requirement of a laccase mediator system. Aspergillus sp. HB_RZ4 was observed to be a potent natural producer of laccase, and it decolorized the dyes even in the absence of a laccase mediator system. Thus, it can be used for bioremediation of effluent that contains non-textile dyes.

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“…Laccases are sensitive for metals even at low concentrations and inhibit the laccase activity. Good induction of enzyme activity in presence of CuSO4 is due to the filling of type-2 copper-binding sites with copper ions and due to the reason that Cu is the major inducer for laccase [51] as the catalytic center of the enzyme contains Cu ions. Xin and Geng [52] also copper sulfate best inducer for laccase production in Trametes versicolor.…”

Section: Discussionmentioning

confidence: 99%

Tree bark scrape fungus: A potential source of laccase for application in bioremediation of non-textile dyes

Bhamare¹,

Sayyed

Marraiki

et al. 2020

Preprint

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Although laccase has been recognized as a wonder molecule, and green enzyme, the use of low yielding fungal strains, poor production, purification, and low enzyme kinetics have hampered its larger-scale applications. Hence the present research was aimed to select high yielding fungal strains and to optimize the production, purification, and kinetics of laccase of Aspergillus sp. HB_RZ4. Aspergillus sp. HB_RZ4 produced a copious amount of laccase on under meso-acidophillic shaking conditions in a medium containing glucose and yeast extract. A 25 µM of CuSO 4 enhanced the enzyme yield. The enzyme was best purified on Sephadex G-100 column. Purified enzyme resembled with the laccase of A. flavus. Kinetics of purified enzyme revealed the high substrate specificity and good velocity of reaction with ABTS as substrate. The enzyme was stable over a wide range of pH and temperature. The peptide structure of the purified enzyme resembled with the laccase of A. kawachii IFO 4308. The fungus decolorized various dyes independent of the requirement of a laccase mediator system (LMS). Aspergillus sp. HB_RZ4 came out as a potent natural producer of laccase, it decolorized the dyes even in absence of LMS and thus can be used for bioremediation.

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The reversible depletion and reconstitution of a copper ion in Coprinus cinereus laccase followed by spectroscopic techniques

Cited by 17 publications

References 53 publications

A comparative structural analysis of the surface properties of asco-laccases

A comparative structural analysis of the surface properties of asco-laccases

Tree bark scrape fungus: A potential source of laccase for application in bioremediation of non-textile dyes

Tree bark scrape fungus: A potential source of laccase for application in bioremediation of non-textile dyes

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