Page last updated: 2024-10-24

lactoperoxidase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: 2 a phenolic donor + H2O2 = 2 a phenolic radical donor + 2 H2O. [PMID:19339248, RHEA:56136]

Lactoperoxidase activity is a molecular function associated with enzymes that catalyze the oxidation of various substrates, including iodide, thiocyanate, and hydrogen peroxide. This activity is crucial for the production of hypothiocyanite (OSCN-) and hypoiodite (OI-) ions, which are potent antimicrobial agents. Lactoperoxidase, the enzyme responsible for this activity, is found in various biological fluids such as milk, saliva, and tears. The enzyme utilizes hydrogen peroxide as an oxidant to convert iodide and thiocyanate into their respective hypohalides. These hypohalides are highly reactive and exhibit broad-spectrum antimicrobial activity against bacteria, fungi, and viruses. The mechanism involves the formation of a complex between lactoperoxidase, hydrogen peroxide, and halide ions. Subsequently, the complex undergoes a reaction to generate the hypohalides, which are then released to exert their antimicrobial effects. Lactoperoxidase activity is essential for the innate immune system of mammals, providing a first line of defense against invading pathogens. The production of hypohalides by lactoperoxidase contributes to the antimicrobial properties of various biological fluids, effectively protecting against infections and maintaining the health of the host organism.'
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Proteins (2)

ProteinDefinitionTaxonomy
LactoperoxidaseA lactoperoxidase that is encoded in the genome of cow. [OMA:P80025, PRO:DNx]Bos taurus (cattle)
LactoperoxidaseA lactoperoxidase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P22079]Homo sapiens (human)

Compounds (18)

CompoundDefinitionClassesRoles
gallic acidgallate : A trihydroxybenzoate that is the conjugate base of gallic acid.trihydroxybenzoic acidantineoplastic agent;
antioxidant;
apoptosis inducer;
astringent;
cyclooxygenase 2 inhibitor;
EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor;
geroprotector;
human xenobiotic metabolite;
plant metabolite
hydralazinehydralazine : The 1-hydrazino derivative of phthalazine; a direct-acting vasodilator that is used as an antihypertensive agent.

Hydralazine: A direct-acting vasodilator that is used as an antihypertensive agent.
azaarene;
hydrazines;
ortho-fused heteroarene;
phthalazines
antihypertensive agent;
vasodilator agent
metoclopramidemetoclopramide : A member of the class of benzamides resulting from the formal condensation of 4-amino-5-chloro-2-methoxybenzoic acid with the primary amino group of N,N-diethylethane-1,2-diamine.

Metoclopramide: A dopamine D2 antagonist that is used as an antiemetic.
benzamides;
monochlorobenzenes;
substituted aniline;
tertiary amino compound
antiemetic;
dopaminergic antagonist;
environmental contaminant;
gastrointestinal drug;
xenobiotic
methyl gallatemethyl 3,4,5-trihydroxybenzoate : A gallate ester obtained by the formal condensation of gallic acid with methanol. It exhibits anti-oxidant, anti-tumor, anti-microbial and anti-inflammatory properties.

methyl gallate: has both immunosuppressive and phytogenic antineoplastic activities; isolated from Acer saccharinum
gallate esteranti-inflammatory agent;
antioxidant;
plant metabolite
carbimazolecarbimazole : A member of the class of imidazoles that is methimazole in which the nitrogen bearing a hydrogen is converted into its ethoxycarbonyl derivative. A prodrug for methimazol, carbimazole is used for the treatment of hyperthyroidism.

Carbimazole: An imidazole antithyroid agent. Carbimazole is metabolized to METHIMAZOLE, which is responsible for the antithyroid activity.
1,3-dihydroimidazole-2-thiones;
carbamate ester
antithyroid drug;
prodrug
epigallocatechin gallate(-)-epigallocatechin 3-gallate : A gallate ester obtained by the formal condensation of gallic acid with the (3R)-hydroxy group of (-)-epigallocatechin.

epigallocatechin gallate: a steroid 5alpha-reductase inhibitor and antimutagen in green tea (Camellia sinensis)
flavans;
gallate ester;
polyphenol
antineoplastic agent;
antioxidant;
apoptosis inducer;
geroprotector;
Hsp90 inhibitor;
neuroprotective agent;
plant metabolite
salicylhydroxamic acidhydroxamic acid;
phenols
antibacterial drug;
EC 1.11.2.2 (myeloperoxidase) inhibitor;
EC 3.5.1.5 (urease) inhibitor;
trypanocidal drug
epicatechin(-)-epicatechin : A catechin with (2R,3R)-configuration.catechin;
polyphenol
antioxidant
gallocatechol(-)-epigallocatechin : A flavan-3,3',4',5,5',7-hexol having (2R,3R)-configuration.catechin;
flavan-3,3',4',5,5',7-hexol
antioxidant;
food component;
plant metabolite
procyanidin b2procyanidin B2 : A proanthocyanidin consisting of two molecules of (-)-epicatechin joined by a bond between positions 4 and 8' in a beta-configuration. Procyanidin B2 can be found in Cinchona pubescens (Chinchona, in the rind, bark and cortex), in Cinnamomum verum (Ceylon cinnamon, in the rind, bark and cortex), in Crataegus monogyna (Common hawthorn, in the flower and blossom), in Uncaria guianensis (Cat's claw, in the root), in Vitis vinifera (Common grape vine, in the leaf), in Litchi chinensis (litchi, in the pericarp), in the apple, in Ecdysanthera utilis and in red wine.biflavonoid;
hydroxyflavan;
polyphenol;
proanthocyanidin
antioxidant;
metabolite
proanthocyanidin a2proanthocyanidin A2 : A proanthocyanidin obtained by the condensation of (-)-epicatechin units.

procyanidin A2: structure in first source
hydroxyflavan;
proanthocyanidin
angiogenesis modulating agent;
anti-HIV agent;
antioxidant;
metabolite
procyanidin C1procyanidin C1 : A proanthocyanidin consisting of three (-)-epicatechin units joined by two successive (4beta->8)-linkages.

procyanidin trimer C1: a flavonoid found in multiple plant sources including grape, apple, and cacao, which has antioxidant and anti-inflammatory properties
hydroxyflavan;
polyphenol;
proanthocyanidin
anti-inflammatory agent;
antioxidant;
EC 1.17.3.2 (xanthine oxidase) inhibitor;
EC 3.2.1.20 (alpha-glucosidase) inhibitor;
lipoxygenase inhibitor;
metabolite
1,3,6-tri-o-galloyl-beta-d-glucose1,3,6-tri-O-galloylglucose: structure in first source
methimazolemethimazole : A member of the class of imidazoles that it imidazole-2-thione in which a methyl group replaces the hydrogen which is attached to a nitrogen.

Methimazole: A thioureylene antithyroid agent that inhibits the formation of thyroid hormones by interfering with the incorporation of iodine into tyrosyl residues of thyroglobulin. This is done by interfering with the oxidation of iodide ion and iodotyrosyl groups through inhibition of the peroxidase enzyme.
1,3-dihydroimidazole-2-thionesantithyroid drug
chlorogenic acidcaffeoylquinic acid: Antiviral Agent; structure in first source

chlorogenate : A monocarboxylic acid anion that is the conjugate base of chlorogenic acid; major species at pH 7.3.
cinnamate ester;
tannin
food component;
plant metabolite
quercetin7-hydroxyflavonol;
pentahydroxyflavone
antibacterial agent;
antineoplastic agent;
antioxidant;
Aurora kinase inhibitor;
chelator;
EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor;
geroprotector;
phytoestrogen;
plant metabolite;
protein kinase inhibitor;
radical scavenger
apigeninChamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia.trihydroxyflavoneantineoplastic agent;
metabolite
ellagic acidcatechols;
cyclic ketone;
lactone;
organic heterotetracyclic compound;
polyphenol
antioxidant;
EC 1.14.18.1 (tyrosinase) inhibitor;
EC 2.3.1.5 (arylamine N-acetyltransferase) inhibitor;
EC 2.4.1.1 (glycogen phosphorylase) inhibitor;
EC 2.5.1.18 (glutathione transferase) inhibitor;
EC 2.7.1.127 (inositol-trisphosphate 3-kinase) inhibitor;
EC 2.7.1.151 (inositol-polyphosphate multikinase) inhibitor;
EC 2.7.4.6 (nucleoside-diphosphate kinase) inhibitor;
EC 2.7.7.7 (DNA-directed DNA polymerase) inhibitor;
EC 5.99.1.2 (DNA topoisomerase) inhibitor;
EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor;
food additive;
fungal metabolite;
geroprotector;
plant metabolite;
skin lightening agent