Ligand urea

increase of activity by 250% in presence of 1 M urea with no apparent perturbation in enzyme structure. Presence of urea prohibits the closing of the active site thus allowing the substrate to bind

677049

2.1.1.165

activity in 1, 2, and 3 M urea is about 1.75-, 2-, and 1.5-fold higher than in the absence of urea, respectively

682595

2.1.1.77

recombinant enzyme relative activity is greatest in liquid assays in 1 M urea

activates

enhances activity of TCH4 protein

2 mM, activates

enhances activity together with dithiothreitol

489800

2.4.2.4

stimulates at low concentration, inhibits at high concentration, 4 M

638445

2.7.4.3

up to 1 M, 60% increase in activity

at concentrations lower than 0.8 M

2 M, stimulation

100.2% activity at 10 mM

761050

3.2.1.1

urea enhances the activity 47% more than the original activity at 5 mM

112% activity at 1 mM

5 mM, 119% of initial activity

735843

3.2.1.41

1.0-5.0 mM, 1.1fold activation

721324

3.2.1.55

118% activity at 10 mM

715952

3.2.1.67

110.38% activity at 5 mM

750600

3.2.1.78

122.7% activity at 5 mM

low concentrations stimulate

stimulates

23% activation at 1 M

754408

3.4.21.9

addition of urea (1-4 M) greatly improves enterokinase cleavage specificity at the canonical site and reduces adventitious cleavage

701055

3.4.21.B57

slight activation at 1-4 M

732679

3.4.22.15

enhances hydrolysis of azocasein

at 5 M and 8-9 M

activity decreases in the presence of 4 M urea and reaches the activity of the control again at 8 M when using casein as a substrate

682716

3.4.22.37

3fold activation at 6 M, probably due to unfolding of the substrate azocasein, which enhances the enzymes sensitivity for proteolytic cleavage

650451

3.4.22.50

3 M, enhances activity

stimulates

optimal concentration: 4-5 M, inclusion bodies from Escherichia coli as substrate

19% increase of activity at 1% (w/v)

684594

3.6.1.22

8 M urea, 30 mM Phosphate buffer, pH 7.4, 100% activation

209951

3.6.1.7

R97Q mutant, at low urea concentration, sharp activation with maximum, about 50% activation at 3 M urea, followed by rapid inactivation: 6 M: 80% inhibition, 8 M: 100% inhibition

246795

4.1.1.36

0.2-0.5 M, increases activity

4411

4.2.1.104

strong inducer of cyanase activity

up to 1 M of urea

Inhibitor in Enzyme-catalyzed Reactions (410 results)

FabG is fully unfolded at 6 M, approximately 90% of the enzyme activity can be recovered on dialyzing the denaturant. Two states in the reversible unfolding process of FabG in presence of NADPH, one is an activity-enhanced state and the other, an inactive state in case of equilibrium unfolding with urea

at pH 9.9

inactive at 3 M but regains activity after dialysis

strong inhibition

2.2 mM, 50% inhibition, reversible

286332

1.1.1.27

enzyme activity and electrophoretic pattern of LDH-A4 and malate dehydrogenase, EC 1.1.1.37, compared in relation to heat and urea inactivation, LDH is more sensitive than MDH, overview

688101

1.1.1.359

40% (v/v), 85% activity

639106

1.1.1.37

enzyme activity and electrophoretic pattern of MDH and lactate dehydrogenase, EC 1.1.1.27, compared in relation to heat and urea inactivation, LDH is more sensitive than MDH, overview

688101

1.1.1.39

denaturation, in 3-5 M urea, the enzyme undergoes a reversible tetramer-dimer-monomer quaternary structural change in an acidic pH environment, which resulted in a molten globule state that is prone to aggregate, Mn2+ protects, overview

685622

1.1.1.40

inactivation at 3-5 M urea, the pigeon cytosolic NADP+-dependent malic enzyme unfolds and aggregates into various forms with dimers as the basic unit, under the same denaturing conditions but in the presence of 4 mM Mn2+, the enzyme exists exclusively as a molten globule dimer in solution, overview

685622

1.1.1.42

low molecular weight form

286781

1.1.1.49

inhibition in vitro and in vivo at sublethal concentration of 0.02-0.05 mM, IC50: 0.0238 mM

oxidized truncated enzyme

287392

1.1.1.B3

1 M, 5.8% residual activity

689823

1.1.3.13

6 M, at 30°C for 1-2 h: partial inactivation, urea + KBr: complete inactivation

urea causes a dose-dependent but reversible inhibition by dissoziation of the hetero-oligomeric enzyme comparable with the effect of heat-treatment, 3.5 M urea reduces GDH activity by 20%, 5 M urea by 80% and 8 M urea by ca. 90%

effect on various molecular forms

439924

1.11.1.14

1% w/v, 85% residual activity

742684

1.11.1.6

50% inhibition at 4 M in 3.5 min

439775

1.11.1.7

loss of more than 50% of its activity at 1M urea

763934

1.12.7.2

at 10 mM inhibitory, hydrogen production

439676

1.13.11.27

1 M, 3% inhibition. 3 M, 42% inhibition. 5 M, 56% inhibition

727448

1.13.11.48

causes isothermal unfolding of mutant C69S in a three-state mechanism, thermodynamic analysis, overview; nonlinear decrease of activity, activity lost at about 5 M, three-state unfolding of mutant enzyme

1-4 M

86% inhibition at 4 M

744574

1.13.12.6

at 5.0 M urea, the half-time of the enzyme is 45 min, at 6.0 M urea 8 min, and at 7.5 M urea, the enzyme is inactivated within 1 min. r´Reversible, non-competitive inhibition of the luciferase activity occurs at concentrations up to 1.5 M

70% loss of activity at 1 M

denaturation curve, thermodynamics, wild-type and mutants, overview

657927

1.14.16.6

2.0 mM, complete inhibition

1 M urea reduces activity by 20%, 2 M urea by 40%, and 3 M urea by 80%, concentrations over 5 M urea eliminate activity

698664

1.18.6.1

immediate inhibition, repression of induction

440160

1.2.1.5

500 mM, 44% inhibition

722210

1.2.1.59

the enzyme retains more than 50% activity after 72 h of incubation in the presence of 6 M urea, and 40% at 8 M urea

no activity at 2.5 M

no modification with 8 M urea

3.5 M, complete and irreversible inactivation

391694

1.4.2.1

30% inhibition at 50 mM

about 50% inhibition of isoform LAAOII and about 20% inhibition of isoform LAAOI at 5 mM

743013

1.4.3.5

both activates and denatures the enzyme, reversible inactivation above 2.5 M, half-time of inactivation is 46 min at 2 M and 37°C

at 4 M, 38% inhibition and at 7.2 M, 93% inhibition

42.8% residual activity at 10 mM

764599

1.7.1.17

50% activity is lost up to 2 M urea concentration and complete loss of activity is observed at 4 M urea

4 M, 60% inhibition

50% inhibition at 6 mM

1 mM urea has no significant effect on activity whereas 50% enzyme inhibition is observed at 750 mM, enzyme after treatment with urea below 500 mM regains about 95% activity

696460

1.8.1.7

activation: 0.4-0.6 M, inactivation at higher concentration

394733

1.8.3.2

1 mM, 80% residual activity

724654

1.8.3.3

1 mM, 80% residual activity

2.5 M, almost complete inhibition

485863

2.2.1.1

denaturation of holo-transketolase by urea displays at least three transitions, where only the final equilibrium denaturation transition is the same for both apo-transketolase and holo-transketolase. Enzyme is deactivated initially by changes in structure associated with the cofactors, but this event does not release the cofactor from the enzyme. Holo-transketolase does not denature to apo-transketolase at 2 M urea. Complete dissociation of cofactors from holo-transketolase at 3.8 M urea without formation of the compact form of apo-transketolase (intermediate form). Holo-transketolase and apo-transketolase at 7.2 M urea both show a common denatured form

692117

2.3.1.41

about 50% inhibition at 1 M, complete inactivation at 4 M

inactivation at 8 mM

complete inactivation of wild-type and mutant at 6 M, low activity at 4 M

487961

2.3.3.16

irreversible inactivation of recombinant wild-type at 9.3 M and of recombinant mutant G196V at 5 M, at up to 8 M activation of the wild-type

10 mM, 15% inhibition; 85% inhibition

inhibition at high concentration, 4 M, stimulation at low concentration

638445

2.5.1.15

0.9 M, 50% inhibition

loss of 81% activity at 2 M, 50% at 1 M

722293

2.6.1.5

the enzyme shows a gradual decrease in the activity till 2.5 M urea, after which the complete loss of activity is measured

759200

2.7.1.1

722079, 738076, 739595

8 M, 20% inhibition

6 M, complete inactivation

plus dithiothreitol and IAA

urea-induced unfolding of thymidylate kinase is noncooperative and influences the functional properties of the enzyme much less than their Cm values. Complete inhibition at 1.0 M

738404

2.7.6.3

0.9 M, 50% inhibition

662800

2.7.7.15

50% inhibition of wild-type enzyme at 0.75 M, 50% inhibition of H92N mutant enzyme at 0.35 M, 50% inhibition of H92Q mutant enzyme at 0.2 M

642924

2.7.7.2

the enzymatic activity of isoform FADS2 decreases dramatically at increasing urea concentration, with a mid-point for activity loss at 2.1 m urea

722239

3.1.1.1

5 mM, 16% loss of activity (recombinant enzyme expressed in Sulfolobus solfataricus). 5 mM, 17% loss of activity (recombinant enzyme expressed in Escherichia coli as thioredoxin-free form (EcSisEstA I)). 5 mM, 10% loss of activity (recombinant enzyme expressed in Escherichia coli as a thioredoxin-EstA fusion protein (EcSisEstA II))

10 mM, 15% loss of activity

strong inhibition

the stability of the immobilized recombinant enzyme is 2.7fold increased compared to the soluble recombinant enzyme

7.0 M, inactivation

20% inhibition at 4 M

40% of maximal activity with single-stranded DNA with 6.6 M

slight inhibition

in vivo: activity decreases in vivo (mIMCD-3 cell), measuring choline by chemiluminescence, substrate sn-glycero-3-phosphocholine. in vitro: no directl inhibition of GDPD5 activity, GPC-PDE in vitro activity is reduced by over 60% in immuno-precipitates from HEK293 cells exposed to high urea concentration.

88% residual activity in the presence of 8 M urea, after 60 min at 70°C

1 M, 74% inhibition

2 mM, 57% of initial activtiy

90.4% residual activity at 10 mM

752333

3.2.1.176

0.1 M, 55% inhibition

20% loss of activity at 8 M

isoform Ag-II shows 92% residual activity at 5 mM urea

10 mM, 6% inhibition

1%, 38% inhibition

100% inhibition at 3 M

relative activity in presence of 2 M 32%

136608

3.2.1.55

84.86% residual activity at 1 M

713698

3.2.1.6

10 mM, 85% residual activity

14.5% residual activity at 7 mM

681159

3.2.1.78

about 70% residual activity at 100 mM

85.86% residual activity at 10 mM

competitive

completely inactive in presence of 6 M urea

2.0 M

sensitive to very low concentrations of urea

weak

12% residual activity in the presence of 4 mM urea

high concentrations (6 M) of urea significantly decrease the enzyme activity by over 60%, most likely due to disrupting the enzyme structural integrity

slight inhibition

5 mM, 50% loss of activity in absence of CaCl2

inactivated at 3 M

the reversible unfolding/refolding process of the PLpro in the presence of urea is investigated. The zinc-binding domain of the enzyme starts to unfold at urea concentration below 0.35 M and reaches a first plateau at 1-3.5 M. At this stage, the palm and thumb core domains remain well folded but totally inactive

733209

3.4.22.33

at 2.4 M urea the activity decreases continuously to 50% when using N-alpha-benzoyl-DL-arginine-2-naphthylamide as a substrate

682716

3.4.22.51

70% inhibition at 5 M

638878

3.4.22.68

2 M reduces cleavage to 95%, 3 M reduces cleavage to 5%

666178

3.4.23.12

isoform NepI shows about 85% residual activity at 4 M and is completely inhibited at 6 M urea

752478

3.4.23.18

95.5% residual activity at 5 mM

50 mM, 72% residual activity

5 M, not at 2 M

complete inhibition at 8 M

inhibits 95.7% at 8 M, no inhibition at 4 M

0.5 M

6 M, irreversible inactivation

95% loss of activity in 2.25 M

moderate inhibition

inhibition kinetics and effects on enzyme structure, overview

competitive

80% inhibition at 2 M

733540

3.5.1.67

slight inhibition, 10 mM: 10% inhibition

20% inhibition at 1 mM

competitive inhibition

5% and 20% activity loss with 2 M and 5 M urea pre-treatment for 10 min at 30°C

0.2-1 M

8 M, both isoenzymes

above 2 M, reversible inactivation

weak

deactivation by denaturation of the protein

678196

3.8.1.5

79% inhibitin at 4 M, 93% at 8 M

8 M, denaturates

about 100% inhibition at concentration of 4 mM

4 mM: inactivation

partial inactivation

20% activity remains at 3 M urea, and no activity is detected in 6 M urea

709132

4.2.1.20

the beta-elimination activity of the enzyme complex decrease less sharply than the beta-replacement activity with increasing concentration in absence of NaCl, 0.1 M NaCl alters the effect of urea concentration

13.9% inhibition at 1 mM

1 mM, 22% inhibition

1 mM, 86% of initial activity

complete inhibition at a concentration of 1 M in triethanolamine hdrochloride buffer, folate and pteroylpolyglutamates protect

above 1 mM

competitive

addition of 1 M urea reduces activity to 58%

648704

4.5.1.1

98% loss of activity at 10 mM

714003

4.6.1.18

mechanism of inhibition, urea inhibits ribonuclease A competitively over a concentration range from 100 mM to 4.0 M, urea with its high dipolar moment is a competitive inhibitor and a very high concentration (more than 4.0 M) of it could denature the enzyme, beginning the interaction with the protein at the active center

707508

5.1.3.8

50% inhibition at 2 M, 10% at 1 M

8 M, completely and irreversibly inactivates

4 M

90% inhibition at 2 M, 1% inhibition of aggregated enzyme

728159

5.6.2.1

inhibitory effect to W203A/W205A/W206A mutant

690816

6.1.1.7

denaturation at 3.3 M, the Zn2+-depleted enzyme is much more sensitive to denaturation by urea than the native enzyme

649422

6.2.1.4

the Thermus aquaticus enzyme loses activity at 4-5.5 M urea, but it regains activity with increasing concentrations of urea, reaching 70% of its original activity in 8.5 M urea

726583

6.3.1.2

physiological concentrations of urea inhibit, at least when ATP and/or glutamate are nonsaturating. Inhibition is partially reversed by trimethylamine-N-oxide

37504

6.3.4.21

competitive to nicotinate mononucleotide

20% inhibition with 100 mM, 50% inhibition with 250 mM, 90% inhibition with 800 mM

644267