Förster energy transfer from tryptophan to flavin in glucose oxidase enzyme

Haouz, Ahmed; Twist, Charles; Zentz, Christian; Kersabiec, Anne‐Marie de; Pin, Serge; Alpert, Bernard

doi:10.1016/s0009-2614(98)00852-5

Cited by 27 publications

(19 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Energy transfer from the tryptophan residues to the flavin cofactor appeared to influence quantum yields of tryptophan. As reported earlier, all of the tryptophan residues of each of the subunits transfer energy to the flavin moiety (20).…”

Section: Figsupporting

confidence: 55%

“…Intrinsic protein fluorescence measurements indicate a higher quantum yield for tryptophan without a change in the emission maximum. Changes in the fluorescence intensity are the result of FAD removal only (20). The overlapping melting curves for the loss of enzyme activity and FAD dissociation, secondary and tertiary structure loss emphasize the critical role of FAD in maintaining the active structure of the enzyme.…”

Section: Discussionmentioning

confidence: 97%

“…Studies on the reduced and oxidized holoenzyme as well as the apoenzyme revealed that in the native conformation of the enzyme, seven tryptophan residues and FAD are in proximity. The quenching of fluorescence was the result of a Förster energy transfer from the tryptophan residues to the flavin group (20). Addition of salts to the native enzyme did not affect the tryptophan fluorescence emission significantly.…”

Section: Figmentioning

confidence: 91%

See 2 more Smart Citations

Thermal Inactivation of Glucose Oxidase

Gouda

Singh

Rao

et al. 2003

Journal of Biological Chemistry

171

View full text Add to dashboard Cite

Thermal inactivation of glucose oxidase (GOD; ␤-Dglucose: oxygen oxidoreductase), from Aspergillus niger, followed first order kinetics both in the absence and presence of additives. Additives such as lysozyme, NaCl, and K 2 SO 4 increased the half-life of the enzyme by 3.5-, 33.4-, and 23.7-fold respectively, from its initial value at 60°C. The activation energy increased from 60.3 kcal mol ؊1 to 72.9, 76.1, and 88.3 kcal mol ؊1 , whereas the entropy of activation increased from 104 to 141, 147, and 184 cal⅐mol ؊1 ⅐deg ؊1 in the presence of 7.1 ؋ 10 ؊5 M lysozyme, 1 M NaCl, and 0.2 M K 2 SO 4 , respectively. The thermal unfolding of GOD in the temperature range of 25-90°C was studied using circular dichroism measurements at 222, 274, and 375 nm. Size exclusion chromatography was employed to follow the state of association of enzyme and dissociation of FAD from GOD. The midpoint for thermal inactivation of residual activity and the dissociation of FAD was 59°C, whereas the corresponding midpoint for loss of secondary and tertiary structure was 62°C. Dissociation of FAD from the holoenzyme was responsible for the thermal inactivation of GOD. The irreversible nature of inactivation was caused by a change in the state of association of apoenzyme. The dissociation of FAD resulted in the loss of secondary and tertiary structure, leading to the unfolding and nonspecific aggregation of the enzyme molecule because of hydrophobic interactions of side chains. This confirmed the critical role of FAD in structure and activity. Cysteine oxidation did not contribute to the nonspecific aggregation. The stabilization of enzyme by NaCl and lysozyme was primarily the result of charge neutralization. K 2 SO 4 enhanced the thermal stability by primarily strengthening the hydrophobic interactions and made the holoenzyme a more compact dimeric structure.

show abstract

Section: Figsupporting

confidence: 55%

Section: Discussionmentioning

confidence: 97%

Section: Figmentioning

confidence: 91%

See 1 more Smart Citation

Thermal Inactivation of Glucose Oxidase

Gouda

Singh

Rao

et al. 2003

Journal of Biological Chemistry

171

View full text Add to dashboard Cite

show abstract

“…Enzyme structure may be studied by fluorescence spectroscopy [238][239][240][241][242][243][244]. Excitation in the 280-310 nm absorption bands of proteins, usually results in fluorescence from tryptophan (Trp) residues in the 310-390 nm region.…”

Section: Enzyme-host Structure Interactionsmentioning

confidence: 99%

Enzyme‐Based Bioinorganic Materials

Forano

Prévot

2007

Bio‐inorganic Hybrid Nanomaterials

View full text Add to dashboard Cite

Trends in research materials currently focus on innovation in the field of intelligent or smart materials [1]. Smart materials are materials that display functionalities able to detect a change in the near environment, answer to a stimulus, modify a property, store, transfer or convert a signal, in a sense behave like living cells. The design of smart materials focuses on the concept of biomimetic materials [2][3][4] in order to reproduce specific and selective properties not deliverable by standard chemical or physical processes. Hence, there has been much effort concentrated on the development of enzyme-based biohybrid materials. Enzyme-based biohybrid materials are under much investigation for the operation of physical or chemical functions. Enzymes display active and selective properties such as molecular recognition, complexation or carrier functions, and a wide range of catalytic reactions (hydrolysis, condensation, redox reaction, isomerization, reaction transfer). Enzymes are thus very attractive as an alternative to traditional catalysts when chemical routes are difficult to apply. Enzymes are able to catalyze regio-and stereo-selective reactions with rate accelerations up to 10-17 fold [17]. They are interesting materials for realization of sensing devices, recognition systems and nanoreactors with many potential industrial developments in biocatalysis [4] for the food industry or effluent treatment [5,6], in biomedical domains for medical implants or enzyme delivery [7], in bioanalysis and affinity chromatography [8,9], and in biosensor technology [10][11][12].Engineering the development of biohybrid enzyme-based materials requires solution of the limitations of the use of enzymes due to their intrinsic fragility against the various environmental stresses and their narrow range of working conditions (e.g. short pH and temperature range). Embedding enzymes in protective matrices in order to solve these problems has been envisaged for many years [13,14]. Immobilization of enzymes in solid supports is seen as a strategy to preserve the active site, to improve the performance of the enzyme, that is, its activity, reaction rate and long-term stability, and to allow enzyme reuse. Physical and chemical properties of the solid supports such as particle size, surface area, pore diameter, mechanical j443 Bio-inorganic Hybrid Nanomaterials. Edited

show abstract

“…For instance, living anionic, conventional radical polymerization, atom transfer radical polymerization, and ring-opening metathesis polymerization processes were successfully used to prepare polymers with Py groups. [11][12][13][14][15][16][17][18][19] Py functionalization showed that the strong fluorescence properties of such polymers makes them valuable candidates for a variety of applications in biomolecular interactions including those between antigen and antibody, enzymes and substrates, and nucleic acids and their complementary sequences. A versatile method to synthesize Py-functional poly(vinyl alcohol) (PVA) directly from the PVA using the click chemistry approach has been previously reported [20] and successfully applied as fluorescence probe for both oxidasebased enzyme assay and in vitro cancer diagnosis.…”

Section: Introductionmentioning

confidence: 99%

Polysulfone/Pyrene Membranes: A New Microwell Assay Platform for Bioapplications

Karadag

Yılmaz

Toiserkani

et al. 2011

Macromolecular Bioscience

View full text Add to dashboard Cite

The use of PSU-Py prepared by click chemistry as a platform in membrane-bottom microwell plates for oxidase and hydrolase/oxidase-based enzyme assays is studied. For the GOx assay, the postulated fluorescence mechanism is based on the consumption of glucose by dissolved oxygen and GOx in the microwell plates covered with the PSU-Py membrane. For the AG-GOx assay, maltose is used as AG substrate and hydrolyzed to glucose which is then oxidized by the GOx activity. It is shown that the PSU-Py membrane acts as a fluorescence indicator of the enzymatic reactions, and both GOx and AG/GOx enzyme assays are successfully applied for glucose, maltose and acorbose analysis in the range 0.125-2.0 × 10(-3) M glucose, 0.05-0.5 × 10(-3) M maltose, and 0.0125-0.1 mg · mL(-1) acorbose, respectively.

show abstract

Förster energy transfer from tryptophan to flavin in glucose oxidase enzyme

Cited by 27 publications

References 18 publications

Thermal Inactivation of Glucose Oxidase

Thermal Inactivation of Glucose Oxidase

Enzyme‐Based Bioinorganic Materials

Polysulfone/Pyrene Membranes: A New Microwell Assay Platform for Bioapplications

Contact Info

Product

Resources

About