Ligand iodoacetamide

strong and irreversible inhibition by thiol directed reagents like 4-chloromercuribenzoate, N-methylmaleimide and iodoacetamide suggest the requirement of free-SH groups for the catalytic activity

672427

2.4.1.181

60% inhibition at 1 mM

5 mM, weak

10 mM, about 50% inhibition

weak

1 mM, 65% inhibition

49% inhibition at 1 mM

1 mM, 10% inhibition

slight inhibition of mutant, not wild-type

489719

2.4.2.14

approx. 60% inactivation of amidotransferase activity after 30 min, very weak inactivation of NH3-dependent activity

489747

2.4.2.25

at 1 mM causes an inhibition of 55%, reversed by cysteine

1 mM, 44% inhibition

IC50: 40 mM for homodimeric enzyme, 8.7 mM for heterodimeric enzyme

preincubation, 1 mM, 30 min prior to assay causes 50% inhibition

288700

2.5.1.47

1 mM, 48% loss of activity

676961

2.5.1.54

alkylation, abolishes the dependence on reducing agents

639798

2.5.1.7

inhibition by alkylation of the active site Cys155, pH-dependent, no alkylation below pH 7.0, maximum alkylation at pH 9.0

results in a rapid loss of the component B activity. Component A is resistant, retaining the initial activity almost completely. Farnesyl diphosphate, isopentenyl diphosphate, farnesyl monophosphate and inorganic diphosphate protect the synthase against the inactivation by N-ethylmaleimide, farnesyl diphosphate being the most effective. The presence of Mg2+ is essential for the protection by isopentenyl diphosphate and inorganic diphosphate. For protection of the synthase activity against the inactivation by 2,3-butanedione, the presence of farnesyl diphosphate, isopentenyl diphosphate and Mg2+ is more effective than that of the individual substrates and Mg2+. Inorganic diphosphate provides substantial protection. In the absence of component A, the component B activity is not protected by any substrates or its analogue

10 mM, completely inhibits 4HB geranyltransferase activity

strong inhibition, dithiothreitol partially protects

substrates partially protect against inactivation

641700

2.7.1.6

0.05 mM, complete inactivation

0.125 mM, 60% inhibition. Preincubation with 0.25 mM dithiothreitol for 5 min partially protects

weak

20 mM; 49% inhibition

wild-type: loss of 56% activity after 30 min at 0.1 mM, mutant C123S is not affected

1 mM, 6% remaining activity

643775

2.8.1.1

complete inhibition at 20 mM

724480

2.8.1.7

preincubation dramatically inhibits enzyme activity

pH 7.5, 30°C, inhibition prevented by presence of 3'-phosphate 5'-sulfatophosphate but not by L-tyrosine methyl ester

644820

2.8.3.5

2.5fold increase at 2 mM

645983

3.1.1.112

1 mM, no residual activity

modest inactivation

no effect at a concentration of 3.3 mM

50 mM, 45% inhibition

100% inhibition at 5 mM

638950

3.1.1.80

0.5 mM, 30-40% inhibition

671020

3.1.1.88

0.5 mM, strong inhibition

slight inhibitory

50 mM, 30% inhibition after 1 h at 30°C

94688

3.1.3.2

134702, 134716, 706063

weak

inhibits 32% at 1 mM and 36% at 5 mM

1.0 mM, 16% inhibition

slight inhibition

2 mM: 50% inhibition

weak inhibition

1 mM, 20% inhibition

208597, 208622, 694842

slight inhibition at 1 mM

135974

3.2.1.26

5 mM, about 20% inhibition of isozyme IT I, 44% inhibition of isozyme IT II

665023

3.2.1.28

100 mM required for inhibition of more than 50%

136159

3.2.1.3

78% inhibition at 10 mM, 40% inhibition at 1 mM

highly inhibitory

slight inhibition

30% inhibition at 1 mM

136826, 136842, 136845

5 mM, inhibition to 50% of control

very slight inhibition

weak

1 mM, 57% inhibition

12.3% residual activity at 10 mM

730765

3.4.11.5

slight inhibition at 1 mM, 90% inhibition at 10 mM

0.01 mM, 19% inhibition

1 mM, 20% inhibition

slight

90% inhibition at a concentration of 5 mM

10 mM, 27% inhibition

5.2% inhibition at 5 mM

0.26 mM, 50% inhibition

slight inhibition

5 mM, 84% residual activity

651056, 653256, 653742

1 mM, 64% inhibition

active site Cys184 of sortase A can be alkylated by iodoacetamide resulting in irreversible modified enzyme. The selenol and thiol of mutant Sec-sortase and mutant Hcy-sortase are sensitive to alkylation as well

exceptionally low rat constant for inhibition

30313

3.4.22.B69

enzyme-bound crystal structure analysis, overview

769057

3.4.22.B70

inhibits desumoylation

731615

3.4.22.B78

strong inhibition; strongly inhibits the peptidase activity, confirming that Cys100 is a nucleophilic residue

730765

3.4.23.1

82.1 residual activity at 0.05 mM

717595

3.4.23.4

4 mM iodoacetamide causes inhibition of 7.2% of the milk-clotting activity

slight inhibition at 2 mg/ml

49.9% residual activity at 4 mM

60% residual activity at 0.05 mM

reversible, competitive inhibitor

with 20 micromol iodoacetamide the activity is 20% after 10 min

slight inhibition

slight inhibition at 1 mM

172046

3.5.1.49

complete inhibition at concentrations above 15 mM

718640

3.5.1.5

phosphate protects wild-type enzyme from inactivation, does not affect inactivation of C319S urease

weak

very slight inhibition, 1 mM: 2% inhibition

172070

3.5.1.71

7.5 mM: 100% inhibition

slight inhibition at 1 mM for both formamidases I and II

pH dependent DDAH inactivation, addition of 2.5 mM NG-methyl-L-arginine at pH 8.5 can prevent inactivation by idoacetamide, inactivation may be due to modification at the active site of DDAH, inactivation increases at higher pH values

2-mercaptoethanol partially protects

2 mM iodoacetate inhibits the enzyme activity to 50% or less of its uninhibited value after 15 min incubation with the enzyme at 0°C

less than 10% inhibition

1 mM, 16% inhibition

76% residual activity at 10 mM

pre-incubation results in 25% loss of activity in both cofactor systems

1 mM, 56% inhibition

in the absence of dithiothreitol, the addition of iodoacetamide (4 mM) results in complete loss of activity

partial

50 mM, 56% inhibition

656937

4.2.1.11

binds to cysteine residues

652923

4.2.1.17

10 mM, 20 min, 20% inhibition

inhibition after prolonged incubation

5698

4.2.1.55

0.01 M, 30% inhibition

150 mM, in about 5 min all activity is lost

5 mM, 16% inhibition

weak

1 mM, 70% loss of activity

crotonyl-CoA protects

22% residual activity at 2.5 mM

1 mM, complete inactivation within 3 h

648741, 648743

4.4.1.28

0.42 mM, half-life: 12 min. 17 mM, preincubation completely abolishes activity

slight

irreversible inhibition at pH 5.0, modification site is one of the two catalytic His residues

656707

4.6.1.24

iodoacetamide, but not iodoacetate, reacts with these His residues at pH 8.0, but not at pH 5.5

34943, 34944, 34950

2122, 2124, 653295

weak noncompetitive inhibitor

60% inhibition, protection by 2,3-diphosphoglycerate; protection by 2,3-diphosphoglycerate, or 3-phosphoglycerate, or 2-phosphoglycerate

mutant enzyme Cys119Ala, is less sensitive than wild type enzyme

3736

6.1.1.10

10 mM, weak

6.1.1.15

more than 90% protection by 10 mM ATP or 10 mM ATP + 10 mM Pro

672, 678

inhibits isozyme MtGS1a

728509

6.3.2.11

994, 996

6.3.2.17

2 mM, 30 to 85% loss of activity in 5 min, depending on the enzyme concentration

1120, 1133, 649263

inhibition of Gln-dependent activity, no inhibition of NH4+-dependent activity

3-methylcrotonoyl-CoA protects against inactivation

inactivation

complete inhibition at 0.02 mM

772655

Enzyme Kinetic Parameters

K_i Value (13 results)

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1.1.3.9

5.7

pseudo-first-order kinetics, pH-independent

0.114

pH not specified in the publication, temperature not specified in the publication

0.000075

12.6

pH 7.5, room temperature

0.1

0.26

0.311

pH 6.3, 38°C

661292

IC₅₀ Value (14 results)

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1.2.1.75

0.04

pH 7.8, 65°C

IC50: 40 mM for homodimeric enzyme, 8.7 mM for heterodimeric enzyme

661699

2.7.2.3

1.4

at pH 8.5 and 25Â°C

762312

3.4.11.2

0.098

IC50: 0.098 mM, kidney enzyme

0.003

pH 7.4, 37°C

718465

3.5.4.B9

0.003

at pH 7.8 and 37°C

718465

4.3.1.7

2 entries

References & Links

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Show Reference (1005 entries)

Links to other databases for iodoacetamide

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PubChem

UniChem

Ligand iodoacetamide

Basic Ligand Information

Roles as Enzyme Ligand

Substrate in Enzyme-catalyzed Reactions (1 result)

Activator in Enzyme-catalyzed Reactions (33 results)

Inhibitor in Enzyme-catalyzed Reactions (859 results)

Enzyme Kinetic Parameters

Ki Value (13 results)

IC50 Value (14 results)

References & Links

Literature References (1005)

Links to other databases for iodoacetamide

K_i Value (13 results)

IC₅₀ Value (14 results)