Limits of Versatility of Versatile Peroxidase

ABSTRACTAlthough Mn2+is the most abundant substrate of versatile peroxidases (VPs), repression ofPleurotus ostreatusvp1expression occurred in Mn2+-sufficient medium. This seems to be a biological contradiction. The aim of this study was to explore the mechanism of direct oxidation by VP1 under Mn2+-deficient conditions, as it was found to be the predominant enzyme during fungal growth in the presence of synthetic and natural substrates. The native VP1 was purified and characterized using three substrates, Mn2+, Orange II (OII), and Reactive Black 5 (RB5), each oxidized by a different active site in the enzyme. While the pH optimum for Mn2+oxidation is 5, the optimum pH for direct oxidation of both dyes was found to be 3. Indeed, effectivein vivodecolorization occurred in media without addition of Mn2+only under acidic conditions. We have determined that Mn2+inhibitsin vitrothe direct oxidation of both OII and RB5 while RB5 stabilizes both Mn2+and OII oxidation. Furthermore, OII was found to inhibit the oxidation of both Mn2+and RB5. In addition, we could demonstrate that VP1 can cleave OII in two different modes. Under Mn2+-mediated oxidation conditions, VP1 was able to cleave the azo bond only in asymmetric mode, while under the optimum conditions for direct oxidation (absence of Mn2+at pH 3) both symmetric and asymmetric cleavages occurred. We concluded that the oxidation mechanism of aromatic compounds by VP1 is controlled by Mn2+and pH levels both in the growth medium and in the reaction mixture.IMPORTANCEVP1 is a member of the ligninolytic heme peroxidase gene family of the white rot fungusPleurotus ostreatusand plays a fundamental role in biodegradation. This enzyme exhibits a versatile nature, as it can oxidize different substrates under altered environmental conditions. VPs are highly interesting enzymes due to the fact that they contain unique active sites that are responsible for direct oxidation of various aromatic compounds, including lignin, in addition to the well-known Mn2+binding active site. This study demonstrates the limits of versatility ofP. ostreatusVP1, which harbors multiple active sites, exhibiting a broad range of enzymatic activities, but they perform differently under distinct conditions. The versatility ofP. ostreatusand its enzymes is an advantageous factor in the fungal ability to adapt to changing environments. This trait expands the possibilities for the potential utilization ofP. ostreatusand other white rot fungi.

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The screening of culture condition and properties of xylanase by white-rot fungus Pleurotus ostreatus

Process Biochemistry ◽

10.1016/s0032-9592(03)00290-5 ◽

2004 ◽

Vol 39 (11) ◽

pp. 1561-1566 ◽

Cited By ~ 54

Author(s):

Cai Qinnghe ◽

Yue Xiaoyu ◽

Niu Tiangui ◽

Ji Cheng ◽

Ma Qiugang

Keyword(s):

Culture Condition ◽

Pleurotus Ostreatus ◽

White Rot ◽

White Rot Fungus

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Lignocellulolytic activity of Pleurotus ostreatus under solid state fermentation using silage, stover, and cobs of maize

BioResources ◽

10.15376/biores.16.2.3797-3807 ◽

2021 ◽

Vol 16 (2) ◽

pp. 3797-3807

Author(s):

Magdah Ganash ◽

Tarek M. Abdel Ghany ◽

Mohamed A. Al Abboud ◽

Mohamed M. Alawlaqi ◽

Husam Qanash ◽

...

Keyword(s):

Solid State ◽

Incubation Period ◽

Solid State Fermentation ◽

Pleurotus Ostreatus ◽

White Rot Fungi ◽

Value Added ◽

Extracellular Protein ◽

White Rot ◽

White Rot Fungus ◽

Lignocellulosic Substrate

Lignocellulolytic white-rot fungi allow the bioconversion of agricultural wastes into value-added products that are used in a myriad of applications. The aim of this work was to use corn residues (Zea mays L.) to produce valuable products under solid-state fermentation (SSF) with Pleurotus ostreatus. White-rot fungus P. ostreatus was isolated from maize silage (MS) and thereafter it was inoculated on MS as substrate and compared with maize stover (MSt) and maize cobs (MC) to determine the best lignocellulosic substrate for the production of lignocellulolytic enzymes and extracellular protein. The MS gave the highest productivity of CMCase (368.2 U/mL), FPase (170.5 U/mL), laccase (11.4 U/mL), and MnPase (6.6 U/mL). This is compared to productivity on MSt of 222 U/mL, 50.2 U/mL, 4.55 U/mL, and 2.57 U/mL, respectively; and productivity on MC at the same incubation period as 150.5 U/mL, 48.2 U/mL, 3.58 U/mL, and 2.5 U/mL, respectively. The levels of enzyme production declined with increasing incubation period after 15 and 20 days using MS and MC, respectively, as substrates. Maximum liberated extracellular protein content (754 to 878 µg/mL) was recorded using MS, while a low amount (343 to 408 µg/mL) was liberated with using MSt and MC.

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Transformation of lamotrigine by white-rot fungus Pleurotus ostreatus

Environmental Pollution ◽

10.1016/j.envpol.2019.04.057 ◽

2019 ◽

Vol 250 ◽

pp. 546-553 ◽

Cited By ~ 3

Author(s):

Benny Chefetz ◽

Rotem Marom ◽

Orit Salton ◽

Mariana Oliferovsky ◽

Vered Mordehay ◽

...

Keyword(s):

Pleurotus Ostreatus ◽

White Rot ◽

White Rot Fungus

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A comparative study of production of hydrophobin like proteins (HYD-LPs) in submerged liquid and solid state fermentation from white rot fungus Pleurotus ostreatus

Biocatalysis and Agricultural Biotechnology ◽

10.1016/j.bcab.2019.101440 ◽

2020 ◽

Vol 23 ◽

pp. 101440 ◽

Cited By ~ 2

Author(s):

Shraddha S. kulkarni ◽

Sanjay N. Nene ◽

Kalpana S. Joshi

Keyword(s):

Solid State ◽

Comparative Study ◽

Solid State Fermentation ◽

Pleurotus Ostreatus ◽

White Rot ◽

White Rot Fungus

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Active-Site Plasticity Is Essential to Carbapenem Hydrolysis by OXA-58 Class D β-Lactamase of Acinetobacter baumannii

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01393-15 ◽

2015 ◽

Vol 60 (1) ◽

pp. 75-86 ◽

Cited By ~ 12

Author(s):

Shivendra Pratap ◽

Madhusudhanarao Katiki ◽

Preet Gill ◽

Pravindra Kumar ◽

Dasantila Golemi-Kotra

Keyword(s):

Crystal Structure ◽

Acinetobacter Baumannii ◽

Active Site ◽

Active Sites ◽

Multidrug Resistant ◽

Crystal Structure Analysis ◽

Content Type ◽

Class D ◽

Enzyme Species ◽

Hydroxyethyl Group

ABSTRACTCarbapenem-hydrolyzing class D β-lactamases (CHDLs) are a subgroup of class D β-lactamases, which are enzymes that hydrolyze β-lactams. They have attracted interest due to the emergence of multidrug-resistantAcinetobacter baumannii, which is not responsive to treatment with carbapenems, the usual antibiotics of choice for this bacterium. Unlike other class D β-lactamases, these enzymes efficiently hydrolyze carbapenem antibiotics. To explore the structural requirements for the catalysis of carbapenems by these enzymes, we determined the crystal structure of the OXA-58 CHDL ofA. baumanniifollowing acylation of its active-site serine by a 6α-hydroxymethyl penicillin derivative that is a structural mimetic for a carbapenem. In addition, several point mutation variants of the active site of OXA-58, as identified by the crystal structure analysis, were characterized kinetically. These combined studies confirm the mechanistic relevance of a hydrophobic bridge formed over the active site. This structural feature is suggested to stabilize the hydrolysis-productive acyl-enzyme species formed from the carbapenem substrates of this enzyme. Furthermore, our structural studies provide strong evidence that the hydroxyethyl group of carbapenems samples different orientations in the active sites of CHDLs, and the optimum orientation for catalysis depends on the topology of the active site allowing proper closure of the active site. We propose that CHDLs use the plasticity of the active site to drive the mechanism of carbapenem hydrolysis toward efficiency.

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Involvement of an extracellular H2O2-dependent ligninolytic activity of the white rot fungus Pleurotus ostreatus in the decolorization of Remazol brilliant blue R.

Applied and Environmental Microbiology ◽

10.1128/aem.61.11.3919-3927.1995 ◽

1995 ◽

Vol 61 (11) ◽

pp. 3919-3927 ◽

Cited By ~ 96

Author(s):

B R Vyas ◽

H P Molitoris

Keyword(s):

Pleurotus Ostreatus ◽

White Rot ◽

Brilliant Blue ◽

White Rot Fungus ◽

Ligninolytic Activity ◽

Remazol Brilliant Blue R

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Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H2O2-Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System

Applied and Environmental Microbiology ◽

10.1128/aem.00218-12 ◽

2012 ◽

Vol 78 (16) ◽

pp. 5845-5854 ◽

Cited By ~ 45

Author(s):

Yang Yang ◽

Fangfang Fan ◽

Rui Zhuo ◽

Fuying Ma ◽

Yangmin Gong ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Pichia Pastoris ◽

Oxidative Damage ◽

White Rot ◽

Antioxidative System ◽

White Rot Fungus ◽

Laccase Gene ◽

Content Type ◽

Glutamylcysteine Synthetase

ABSTRACTLaccase is a copper-containing polyphenol oxidase that has great potential in industrial and biotechnological applications. Previous research has suggested that fungal laccase may be involved in the defense against oxidative stress, but there is little direct evidence supporting this hypothesis, and the mechanism by which laccase protects cells from oxidative stress also remains unclear. Here, we report that the expression of the laccase gene from white rot fungus inPichia pastoriscan significantly enhance the resistance of yeast to H2O2-mediated oxidative stress. The expression of laccase in yeast was found to confer a strong ability to scavenge intracellular H2O2and to protect cells from lipid oxidative damage. The mechanism by which laccase gene expression increases resistance to oxidative stress was then investigated further. We found that laccase gene expression inPichia pastoriscould increase the level of glutathione-based antioxidative activity, including the intracellular glutathione levels and the enzymatic activity of glutathione peroxidase, glutathione reductase, and γ-glutamylcysteine synthetase. The transcription of the laccase gene inPichia pastoriswas found to be enhanced by the oxidative stress caused by exogenous H2O2. The stimulation of laccase gene expression in response to exogenous H2O2stress further contributed to the transcriptional induction of the genes involved in the glutathione-dependent antioxidative system, includingPpYAP1,PpGPX1,PpPMP20,PpGLR1, andPpGSH1. Taken together, these results suggest that the expression of the laccase gene inPichia pastoriscan enhance the resistance of yeast to H2O2-mediated oxidative stress by stimulating the glutathione-based antioxidative system to protect the cell from oxidative damage.

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