Altered physicochemical characteristics of polyethylene glycol linked beet stem oxalate oxidase

Varalakshmi, P.; Lathika, K. M.; Raghavan, K.G.; Singh, B. B.

doi:10.1002/bit.260460308

Cited by 9 publications

(4 citation statements)

References 20 publications

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“…The enzyme solution (0. showed some resistance to p-chloromercuribenzoate (36 to 40%) or Fe3+ (30 to 52%), whereas the activity of the free enzyme was about half these values. This resistance has frequently been reported in various types of immobilized enzymes (Nakamura et al, 1995;Varalakshmi et al, 1995). The stimulations (160 to l 68%) by Mn2+ jn the CC-and CAS-enzymes were higher than 124% in the free enzyme.…”

Section: Resultssupporting

confidence: 60%

Preparation and Enzymatic Properties of Aspergillus niger Endoinulinase Immobilized onto Various Polysaccharide Supports.

Zaita

Fukushige

Tokuda

et al. 2000

FSTR

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An extracellular endoinulinase P-III from Aspergillus niger 12 has been immobilized covalently onto bromoacetyl-cellulose (BAC), cellulose-carbonate (CC) and CNBr-activated Sepharose 4B (CAS) with the activity yields of 1 1.9, 24.1 and 19.3 % , respectively, under optimal reaction conditions for the immobilization. All three immobilized enzymes increased the resistance to inactivation by p-chloromercuribenzoate or Fe3'. Mn2. stimulated the activities of the immobilized endoinulinases onto CC (160 %) and CAS (168 %) more remarkably than those of free and BACimmobilized enzymes (124 %). The marked rise from 45 to 60'C in the optimal temperature for inulin hydrolysis was observed in the CAS-immobilized enzyme. The pH stability decreased on the acidic side and increased slightly on the alkaline side in the BAC-inunobilized enzyme, and shifted to the acidic side in the CC-immobilized enzyme. The K~ value decreased in the BAC-immobilized enzyme and increased in the CAS-immobilized enzyme.

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Section: Resultssupporting

confidence: 60%

Preparation and Enzymatic Properties of Aspergillus niger Endoinulinase Immobilized onto Various Polysaccharide Supports.

Zaita

Fukushige

Tokuda

et al. 2000

FSTR

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“…In this work, 80% of the surface lysine residues of the Cyt-PEG 5000 were modified by PEG after the reaction, resulting in a biocatalyst with a predicted molecular weight of 94.7 kDa in which only 13% of the mass is protein. SDS-PAGE electrophoresis and gel filtration chromatography failed to confirm the average molecular weight of this preparation possibly due to the low motility of the polymer in gels (43) or to an increase in the hydrodynamic volume of the protein (38). The modified preparation was analyzed by electrospray mass spectrometry.…”

Section: Resultsmentioning

confidence: 99%

High Temperature Biocatalysis by Chemically Modified Cytochromec

Garcı́a-Arellano¹,

Valderrama²,

Saab‐Rincón³

et al. 2002

Bioconjugate Chem.

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Chemically modified cytochrome c with poly(ethylene glycol) (PEG) showed activity at temperatures higher than 100 degrees C and to be highly thermostable. The molecular size of PEG moieties and the coupling site affected the thermal stabilization. An optimal PEG/protein mass ratio of 2.8 was found, producing a fully thermostable biocatalyst at 80 degrees C. Site-directed mutagenesis on yeast cytochrome c showed an increased thermostabilization when lysine 79 residue, localized at the edge of the active site, was replaced by a nonreactive residue. Tertiary, secondary, and active-site structures were analyzed by fluorescence, CD, and UV/visible spectroscopies. Besides its disordered structure, the pegylated protein showed a lower unfolding rate at the active-site than the unmodified ones. A shell-like structure seems to protect the heme environment, in which PEG is coiled on the protein surface with a primary shield of rigid water molecules solvating the hydrophilic region of bound-PEG, and the PEG hydrophobic regions interacting with the hydrophobic clusters on protein surface.

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“…It should be mentioned that the oxidase‐specific activity of OxDC‐DSSN is lower than the decarboxylase specific activity of OxDC. Nevertheless, the finding that some oxalate oxidases active at neutral pH have been identified supports future studies of rational and/or irrational design of this construct.…”

Section: Resultsmentioning

confidence: 53%

“…Notably, some pieces of evidence allow to speculate that the oxalate oxidase reaction could be performed at neutral pH, possibly because the chemical groups involved in the catalytic mechanism maintain a proper protonation state and/or a proper orientation. In fact, some oxalate oxidases display an optimum pH around 7 , and a recent study reports that the encapsulation of oxalate oxidase from barley into polymeric zwitterionic capsules increases by twofold its activity at neutral pH . Since these enzymes derive from plant sources and their purification is not suitable for large‐scale applications, we thought to the possibility that the oxalate oxidase activity of OxDC‐DSSN could be exploited as an alternative option to degrade oxalate under physiological conditions.…”

Section: Introductionmentioning

confidence: 99%

Biochemical properties and oxalate‐degrading activity of oxalate decarboxylase from bacillus subtilis at neutral pH

et al. 2019

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Oxalate decarboxylase (OxDC) from Bacillus subtilis is a Mn‐dependent hexameric enzyme that converts oxalate to carbon dioxide and formate. OxDC has greatly attracted the interest of the scientific community, mainly due to its biotechnological and medical applications in particular for the treatment of hyperoxaluria, a group of pathologic conditions caused by oxalate accumulation. The enzyme has an acidic optimum pH, but most of its applications involve processes occurring at neutral pH. Nevertheless, a detailed biochemical characterization of the enzyme at neutral pH is lacking. Here, we compared the structural–functional properties at acidic and neutral pH of wild‐type OxDC and of a mutant form, called OxDC‐DSSN, bearing four amino acid substitutions in the lid (Ser161‐to‐Asp, Glu162‐to‐Ser, Asn163‐toSer, and Ser164‐to‐Asn) that improve the oxalate oxidase activity and almost abolish the decarboxylase activity. We found that both enzymatic forms do not undergo major structural changes as a function of pH, although OxDC‐DSSN displays an increased tendency to aggregation, which is counteracted by the presence of an active‐site ligand. Notably, OxDC and OxDC‐DSSN at pH 7.2 retain 7 and 15% activity, respectively, which is sufficient to degrade oxalate in a cellular model of primary hyperoxaluria type I, a rare inherited disease caused by excessive endogenous oxalate production. The significance of the data in the light of the possible use of OxDC as biological drug is discussed. © 2019 IUBMB Life, 1–11, 2019

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Altered physicochemical characteristics of polyethylene glycol linked beet stem oxalate oxidase

Cited by 9 publications

References 20 publications

Preparation and Enzymatic Properties of Aspergillus niger Endoinulinase Immobilized onto Various Polysaccharide Supports.

Preparation and Enzymatic Properties of Aspergillus niger Endoinulinase Immobilized onto Various Polysaccharide Supports.

High Temperature Biocatalysis by Chemically Modified Cytochromec

Biochemical properties and oxalate‐degrading activity of oxalate decarboxylase from bacillus subtilis at neutral pH

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