Catalase

Human catalase forms a tetramer composed of four subunits, each of which can be conceptually divided into four domains.{{cite journal | vauthors = Putnam CD, Arvai AS, Bourne Y, Tainer JA | title = Active and inhibited human catalase structures: ligand and NADPH binding and catalytic mechanism | journal = Journal of Molecular Biology | volume = 296 | issue = 1 | pages = 295–309 | date = February 2000 | pmid = 10656833 | doi = 10.1006/jmbi.1999.3458 }} The extensive core of each subunit is generated by an eight-stranded antiparallel β-barrel (β1-8), with nearest neighbor connectivity capped by β-barrel loops on one side and α9 loops on the other. A helical domain at one face of the β-barrel is composed of four C-terminal helices (α16, α17, α18, and α19) and four helices derived from residues between β4 and β5 (α4, α5, α6, and α7). Alternative splicing may result in different protein variants.

Catalase was first noticed in 1818 by Louis Jacques Thénard, who discovered hydrogen peroxide (H₂O₂). Thénard suggested its breakdown was caused by an unknown substance. In 1900, Oscar Loew was the first to give it the name catalase, and found it in many plants and animals.{{cite journal | vauthors = Loew O | title = A New Enzyme of General Occurrence in Organisms | journal = Science | volume = 11 | issue = 279 | pages = 701–702 | date = May 1900 | pmid = 17751716 | doi = 10.1126/science.11.279.701 | bibcode = 1900Sci....11..701L | jstor = 1625707 | url = https://zenodo.org/record/1447826 }} In 1937 catalase from beef liver was crystallized by James B. Sumner and Alexander Dounce{{cite journal | vauthors = Sumner JB, Dounce AL | title = Crystalline Catalase | journal = Science | volume = 85 | issue = 2206 | pages = 366–367 | date = April 1937 | pmid = 17776781 | doi = 10.1126/science.85.2206.366 | bibcode = 1937Sci....85..366S }} and the molecular weight was measured in 1938.{{cite journal | vauthors = Sumner JB, Gralén N | title = The Molecular Weight of Crystalline Catalase | journal = Science | volume = 87 | issue = 2256 | pages = 284 | date = March 1938 | pmid = 17831682 | doi = 10.1126/science.87.2256.284 | bibcode = 1938Sci....87..284S | s2cid = 36931581 }}

The amino acid sequence of bovine catalase was determined in 1969,{{cite journal | vauthors = Schroeder WA, Shelton JR, Shelton JB, Robberson B, Apell G | title = The amino acid sequence of bovine liver catalase: a preliminary report | journal = Archives of Biochemistry and Biophysics | volume = 131 | issue = 2 | pages = 653–655 | date = May 1969 | pmid = 4892021 | doi = 10.1016/0003-9861(69)90441-X }} and the three-dimensional structure in 1981.{{cite journal | vauthors = Murthy MR, Reid TJ, Sicignano A, Tanaka N, Rossmann MG | title = Structure of beef liver catalase | journal = Journal of Molecular Biology | volume = 152 | issue = 2 | pages = 465–499 | date = October 1981 | pmid = 7328661 | doi = 10.1016/0022-2836(81)90254-0 }}

While the complete mechanism of catalase is not currently known, the reaction is believed to occur in two stages:

: H₂O₂ + Fe(III)-E → H₂O + O=Fe(IV)-E(.+)

: H₂O₂ + O=Fe(IV)-E(.+) → H₂O + Fe(III)-E + O₂{{cite web |vauthors=Boon EM, Downs A, Marcey D | title = Proposed Mechanism of Catalase | work = Catalase: H₂O₂: H₂O₂ Oxidoreductase: Catalase Structural Tutorial | url = http://biology.kenyon.edu/BMB/Chime/catalase/frames/cattx.htm#Proposed%20Mechanism%20of%20Catalase | access-date = 2007-02-11}}

Here Fe()-E represents the iron center of the heme group attached to the enzyme. Fe(IV)-E(.+) is a mesomeric form of Fe(V)-E, meaning the iron is not completely oxidized to +V, but receives some stabilising electron density from the heme ligand, which is then shown as a radical cation (.+).

As hydrogen peroxide enters the active site, it does not interact with the amino acids Asn148 (asparagine at position 148) and His75, causing a proton (hydrogen ion) to transfer between the oxygen atoms. The free oxygen atom coordinates, freeing the newly formed water molecule and Fe(IV)=O. Fe(IV)=O reacts with a second hydrogen peroxide molecule to reform Fe(III)-E and produce water and oxygen. The reactivity of the iron center may be improved by the presence of the phenolate ligand of Tyr358 in the fifth coordination position, which can assist in the oxidation of the Fe(III) to Fe(IV). The efficiency of the reaction may also be improved by the interactions of His75 and Asn148 with reaction intermediates. The decomposition of hydrogen peroxide by catalase proceeds according to first-order kinetics, the rate being proportional to the hydrogen peroxide concentration.{{cite book | vauthors = Aebi H | title = Oxygen Radicals in Biological Systems | chapter = Catalase in vitro | series = Methods in Enzymology | volume = 105 | pages = 121–126 | date = 1984 | pmid = 6727660 | doi = 10.1016/S0076-6879(84)05016-3 | isbn = 9780121820053 }}

Catalase can also catalyze the oxidation, by hydrogen peroxide, of various metabolites and toxins, including formaldehyde, formic acid, phenols, acetaldehyde and alcohols. It does so according to the following reaction:

: H₂O₂ + H₂R → 2H₂O + R

The exact mechanism of this reaction is not known.

Any heavy metal ion (such as copper cations in copper(II) sulfate) can act as a noncompetitive inhibitor of catalase. However, "Copper deficiency can lead to a reduction in catalase activity in tissues, such as heart and liver."{{cite journal | vauthors = Hordyjewska A, Popiołek Ł, Kocot J | title = The many "faces" of copper in medicine and treatment | journal = Biometals | volume = 27 | issue = 4 | pages = 611–621 | date = August 2014 | pmid = 24748564 | pmc = 4113679 | doi = 10.1007/s10534-014-9736-5 }} Furthermore, the poison cyanide is a noncompetitive inhibitor{{cite journal | vauthors = Kremer ML | title = Nonstationary inhibition of enzyme action. The cyanide inhibition of catalase. | journal = The Journal of Physical Chemistry | date = April 1981 | volume = 85 | issue = 7 | pages = 835–839 | doi = 10.1021/j150607a021 }} of catalase at high concentrations of hydrogen peroxide.{{cite journal | vauthors = Ogura Y, Yamazaki I | title = Steady-state kinetics of the catalase reaction in the presence of cyanide | journal = Journal of Biochemistry | volume = 94 | issue = 2 | pages = 403–408 | date = August 1983 | pmid = 6630165 | doi = 10.1093/oxfordjournals.jbchem.a134369 }}

Arsenate acts as an activator.{{cite journal | vauthors = Kertulis-Tartar GM, Rathinasabapathi B, Ma LQ | title = Characterization of glutathione reductase and catalase in the fronds of two Pteris ferns upon arsenic exposure | journal = Plant Physiology and Biochemistry | volume = 47 | issue = 10 | pages = 960–965 | date = October 2009 | pmid = 19574057 | doi = 10.1016/j.plaphy.2009.05.009 | bibcode = 2009PlPB...47..960K }} Three-dimensional protein structures of the peroxidated catalase intermediates are available at the Protein Data Bank.

Hydrogen peroxide is a harmful byproduct of many normal metabolic processes; to prevent damage to cells and tissues, it must be quickly converted into other, less dangerous substances. To this end, catalase is frequently used by cells to rapidly catalyze the decomposition of hydrogen peroxide into less-reactive gaseous oxygen and water molecules.{{cite journal | vauthors = Gaetani GF, Ferraris AM, Rolfo M, Mangerini R, Arena S, Kirkman HN | title = Predominant role of catalase in the disposal of hydrogen peroxide within human erythrocytes | journal = Blood | volume = 87 | issue = 4 | pages = 1595–1599 | date = February 1996 | pmid = 8608252 | doi = 10.1182/blood.V87.4.1595.bloodjournal8741595 | doi-access = free }}

Mice genetically engineered to lack catalase are initially phenotypically normal.{{cite journal | vauthors = Ho YS, Xiong Y, Ma W, Spector A, Ho DS | title = Mice lacking catalase develop normally but show differential sensitivity to oxidant tissue injury | journal = The Journal of Biological Chemistry | volume = 279 | issue = 31 | pages = 32804–32812 | date = July 2004 | pmid = 15178682 | doi = 10.1074/jbc.M404800200 | doi-access = free }} However, catalase deficiency in mice may increase the likelihood of developing obesity, fatty liver,{{cite journal | vauthors = Heit C, Marshall S, Singh S, Yu X, Charkoftaki G, Zhao H, Orlicky DJ, Fritz KS, Thompson DC, Vasiliou V | title = Catalase deletion promotes prediabetic phenotype in mice | journal = Free Radical Biology & Medicine | volume = 103 | pages = 48–56 | date = February 2017 | pmid = 27939935 | pmc = 5513671 | doi = 10.1016/j.freeradbiomed.2016.12.011 }} and type 2 diabetes.{{cite journal | vauthors = Góth L, Nagy T | title = Acatalasemia and diabetes mellitus | journal = Archives of Biochemistry and Biophysics | volume = 525 | issue = 2 | pages = 195–200 | date = September 2012 | pmid = 22365890 | doi = 10.1016/j.abb.2012.02.005 }} Some humans have very low levels of catalase (acatalasia), yet show few ill effects.

The increased oxidative stress that occurs with aging in mice is alleviated by over-expression of catalase.{{cite journal | vauthors = Selvaratnam J, Robaire B | title = Overexpression of catalase in mice reduces age-related oxidative stress and maintains sperm production | journal = Experimental Gerontology | volume = 84 | pages = 12–20 | date = November 2016 | pmid = 27575890 | doi = 10.1016/j.exger.2016.08.012 | s2cid = 2416413 }} Over-expressing mice do not exhibit the age-associated loss of spermatozoa, testicular germ and Sertoli cells seen in wild-type mice. Oxidative stress in wild-type mice ordinarily induces oxidative DNA damage (measured as 8-oxodG) in sperm with aging, but these damages are significantly reduced in aged catalase over-expressing mice. Furthermore, these over-expressing mice show no decrease in age-dependent number of pups per litter. Overexpression of catalase targeted to mitochondria extends the lifespan of mice.{{cite journal | vauthors = Schriner SE, Linford NJ, Martin GM, Treuting P, Ogburn CE, Emond M, Coskun PE, Ladiges W, Wolf N, Van Remmen H, Wallace DC, Rabinovitch PS | title = Extension of murine life span by overexpression of catalase targeted to mitochondria | journal = Science | volume = 308 | issue = 5730 | pages = 1909–1911 | date = June 2005 | pmid = 15879174 | doi = 10.1126/science.1106653 | s2cid = 38568666 | bibcode = 2005Sci...308.1909S }}

In eukaryotes, catalase is usually located in a cellular organelle called the peroxisome.{{cite book |vauthors=Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P | title = Molecular Biology of the Cell | edition = 4th | publisher = Garland Science | location = New York | year = 2002 | chapter = Peroxisomes | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK26858/ | isbn = 978-0-8153-3218-3 }} Peroxisomes in plant cells are involved in photorespiration (the use of oxygen and production of carbon dioxide) and symbiotic nitrogen fixation (the breaking apart of diatomic nitrogen (N₂) to reactive nitrogen atoms). Hydrogen peroxide is used as a potent antimicrobial agent when cells are infected with a pathogen. Catalase-positive pathogens, such as Mycobacterium tuberculosis, Legionella pneumophila, and Campylobacter jejuni, make catalase to deactivate the peroxide radicals, thus allowing them to survive unharmed within the host.{{cite journal | vauthors = Srinivasa Rao PS, Yamada Y, Leung KY | title = A major catalase (KatB) that is required for resistance to H2O2 and phagocyte-mediated killing in Edwardsiella tarda | journal = Microbiology | volume = 149 | issue = Pt 9 | pages = 2635–2644 | date = September 2003 | pmid = 12949187 | doi = 10.1099/mic.0.26478-0 | doi-access = free }}

Like alcohol dehydrogenase, catalase converts ethanol to acetaldehyde, but it is unlikely that this reaction is physiologically significant.{{cite journal | vauthors = Lieber CS | title = Ethanol metabolism, cirrhosis and alcoholism | journal = Clinica Chimica Acta; International Journal of Clinical Chemistry | volume = 257 | issue = 1 | pages = 59–84 | date = January 1997 | pmid = 9028626 | doi = 10.1016/S0009-8981(96)06434-0 }}

The large majority of known organisms use catalase in every organ, with particularly high concentrations occurring in the liver in mammals.{{cite journal| vauthors = Ilyukha VA | journal=Journal of Evolutionary Biochemistry and Physiology | title = Superoxide Dismutase and Catalase in the Organs of Mammals of Different Ecogenesis |date=2001|volume=37|issue=3|pages=241–245|doi=10.1023/A:1012663105999| s2cid=38916410 }} Catalase is found primarily in peroxisomes and the cytosol of erythrocytes (and sometimes in mitochondria{{cite journal | vauthors = Bai J, Cederbaum AI | title = Mitochondrial catalase and oxidative injury | journal = Biological Signals and Receptors | volume = 10 | issue = 3–4 | pages = 189–199 | year = 2001 | pmid = 11351128 | doi = 10.1159/000046887 | s2cid = 33795198 }})

Almost all aerobic microorganisms use catalase. It is also present in some anaerobic microorganisms, such as Methanosarcina barkeri.{{cite journal | vauthors = Brioukhanov AL, Netrusov AI, Eggen RI | title = The catalase and superoxide dismutase genes are transcriptionally up-regulated upon oxidative stress in the strictly anaerobic archaeon Methanosarcina barkeri | journal = Microbiology | volume = 152 | issue = Pt 6 | pages = 1671–1677 | date = June 2006 | pmid = 16735730 | doi = 10.1099/mic.0.28542-0 | doi-access = free }} Catalase is also universal among plants and occurs in most fungi.{{cite journal | vauthors = Hansberg W, Salas-Lizana R, Domínguez L | title = Fungal catalases: function, phylogenetic origin and structure | journal = Archives of Biochemistry and Biophysics | volume = 525 | issue = 2 | pages = 170–180 | date = September 2012 | pmid = 22698962 | doi = 10.1016/j.abb.2012.05.014 }}

One unique use of catalase occurs in the bombardier beetle. This beetle has two sets of liquids that are stored separately in two paired glands. The larger of the pair, the storage chamber or reservoir, contains hydroquinones and hydrogen peroxide, while the smaller, the reaction chamber, contains catalases and peroxidases. To activate the noxious spray, the beetle mixes the contents of the two compartments, causing oxygen to be liberated from hydrogen peroxide. The oxygen oxidizes the hydroquinones and also acts as the propellant.{{cite journal | vauthors = Eisner T, Aneshansley DJ | title = Spray aiming in the bombardier beetle: photographic evidence | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 96 | issue = 17 | pages = 9705–9709 | date = August 1999 | pmid = 10449758 | pmc = 22274 | doi = 10.1073/pnas.96.17.9705 | bibcode = 1999PNAS...96.9705E | doi-access = free }} The oxidation reaction is very exothermic (ΔH = −202.8 kJ/mol) and rapidly heats the mixture to the boiling point.{{cite journal|vauthors=Beheshti N, McIntosh AC|year=2006|title=A biomimetic study of the explosive discharge of the bombardier beetle|url=http://www.heveliusforum.org/Artykuly/Biomimetics.pdf|url-status=dead|journal=International Journal of Design & Nature|volume=1|issue=1|pages=1–9|archive-url=https://web.archive.org/web/20110726145856/http://www.heveliusforum.org/Artykuly/Biomimetics.pdf|archive-date=2011-07-26}}

Long-lived queens of the termite Reticulitermes speratus have significantly lower oxidative damage to their DNA than non-reproductive individuals (workers and soldiers).{{cite journal | vauthors = Tasaki E, Kobayashi K, Matsuura K, Iuchi Y | title = An Efficient Antioxidant System in a Long-Lived Termite Queen | journal = PLOS ONE | volume = 12 | issue = 1 | pages = e0167412 | date = 2017 | pmid = 28076409 | pmc = 5226355 | doi = 10.1371/journal.pone.0167412 | doi-access = free | bibcode = 2017PLoSO..1267412T }} Queens have more than two times higher catalase activity and seven times higher expression levels of the catalase gene RsCAT1 than workers. It appears that the efficient antioxidant capability of termite queens can partly explain how they attain longer life.

Catalase enzymes from various species have vastly differing optimum temperatures. Poikilothermic animals typically have catalases with optimum temperatures in the range of 15-25 °C, while mammalian or avian catalases might have optimum temperatures above 35 °C,{{cite journal| vauthors = Çetinus ŞA, Öztop HN |title=Immobilization of catalase into chemically crosslinked chitosan beads|journal=Enzyme and Microbial Technology|date=June 2003|volume=32|issue=7|pages=889–894|doi=10.1016/S0141-0229(03)00065-6}} and catalases from plants vary depending on their growth habit.{{cite journal| vauthors = Mitsuda H |title=Studies on Catalase|journal=Bulletin of the Institute for Chemical Research, Kyoto University|date=1956-07-31|volume=34|issue=4|pages=165–192|url=https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/75561/1/chd034_4_165.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/75561/1/chd034_4_165.pdf |archive-date=2022-10-09 |url-status=live|access-date=27 September 2017}} In contrast, catalase isolated from the hyperthermophile archaeon Pyrobaculum calidifontis has a temperature optimum of 90 °C.{{cite journal | vauthors = Amo T, Atomi H, Imanaka T | title = Unique presence of a manganese catalase in a hyperthermophilic archaeon, Pyrobaculum calidifontis VA1 | journal = Journal of Bacteriology | volume = 184 | issue = 12 | pages = 3305–3312 | date = June 2002 | pmid = 12029047 | pmc = 135111 | doi = 10.1128/JB.184.12.3305-3312.2002 }}

Image:Wasserstoffperoxid.svg

Catalase is used in the food industry for removing hydrogen peroxide from milk prior to cheese production.{{cite web | url = http://www.worthington-biochem.com/CTL/default.html | title = Catalase | work = Worthington Enzyme Manual | publisher = Worthington Biochemical Corporation | access-date = 2009-03-01}} Another use is in food wrappers, where it prevents food from oxidizing.{{cite web | url = http://madsci.org/posts/archives/mar99/921636249.Gb.r.html | title = Re: how is catalase used in industry? | author = Hengge A | date = 1999-03-16 | work = General Biology | publisher = MadSci Network | access-date = 2009-03-01 | archive-date = 2019-09-07 | archive-url = https://web.archive.org/web/20190907080521/http://madsci.org/posts/archives/mar99/921636249.Gb.r.html | url-status = dead }} Catalase is also used in the textile industry, removing hydrogen peroxide from fabrics to make sure the material is peroxide-free.{{cite web | url = http://www.p2pays.org/ref/11/10842.htm | title = textile industry | work = Case study 228 | publisher = International Cleaner Production Information Clearinghouse | access-date = 2009-03-01 | archive-url = https://web.archive.org/web/20081104083335/http://www.p2pays.org/ref/11/10842.htm | archive-date = 2008-11-04 | url-status = dead }}

A minor use is in contact lens hygiene – a few lens-cleaning products disinfect the lens using a hydrogen peroxide solution; a solution containing catalase is then used to decompose the hydrogen peroxide before the lens is used again.{{US patent reference | number = 5521091 | y = 1996 | m = 05 | d = 28 | inventor = Cook JN, Worsley JL | title = Compositions and method for destroying hydrogen peroxide on contact lens }}

Image:Catalase reaction.jpg

The catalase test is one of the three main tests used by microbiologists to identify species of bacteria. If the bacteria possess catalase (i.e., are catalase-positive), bubbles of oxygen are observed when a small amount of bacterial isolate is added to hydrogen peroxide. The catalase test is done by placing a drop of hydrogen peroxide on a microscope slide. An applicator stick is touched to the colony, and the tip is then smeared onto the hydrogen peroxide drop.

• If the mixture produces bubbles or froth, the organism is said to be 'catalase-positive'. Staphylococci{{cite web | url = http://www.life.umd.edu/classroom/bsci424/pathogendescriptions/PathogenList.htm | title = Bacterial Pathogen List | author = Rollins DM | date = 2000-08-01 | work = BSCI 424 Pathogenic Microbiology | publisher = University of Maryland | access-date = 2009-03-01}} and Micrococci{{cite web | url = http://www.mc.maricopa.edu/~johnson/labtools/Dbiochem/cat.html | title = Catalase Production | author = Johnson M | work = Biochemical Tests | publisher = Mesa Community College | access-date = 2009-03-01 | url-status = dead | archive-url = https://web.archive.org/web/20081211073437/http://www.mc.maricopa.edu/~johnson/labtools/Dbiochem/cat.html | archive-date = 2008-12-11 }} are catalase-positive. Other catalase-positive organisms include Listeria, Corynebacterium diphtheriae, Burkholderia cepacia, Nocardia, the family Enterobacteriaceae (Citrobacter, E. coli, Enterobacter, Klebsiella, Shigella, Yersinia, Proteus, Salmonella, Serratia), Pseudomonas, Mycobacterium tuberculosis, Aspergillus, Cryptococcus, and Rhodococcus equi.
• If not, the organism is 'catalase-negative'. Streptococcus{{cite web | url = http://pathmicro.med.sc.edu/fox/strep-staph.htm | title = Streptococcus pneumoniae and Staphylococci | author = Fox A | publisher = University of South Carolina | access-date = 2009-03-01}} and Enterococcus spp. are catalase-negative.

While the catalase test alone cannot identify a particular organism, it can aid identification when combined with other tests such as antibiotic resistance. The presence of catalase in bacterial cells depends on both the growth condition and the medium used to grow the cells.

Capillary tubes may also be used. A small sample of bacteria is collected on the end of the capillary tube, without blocking the tube, to avoid false negative results. The opposite end is then dipped into hydrogen peroxide, which is drawn into the tube through capillary action, and turned upside down, so that the bacterial sample points downwards. The hand holding the tube is then tapped on the bench, moving the hydrogen peroxide down until it touches the bacteria. If bubbles form on contact, this indicates a positive catalase result. This test can detect catalase-positive bacteria at concentrations above about 10⁵ cells/mL,{{Cite book|url=https://books.google.com/books?id=_orkBwAAQBAJ&pg=PA35|title=Fisheries Processing: Biotechnological applications| vauthors = Martin AM |date=2012-12-06|publisher=Springer Science & Business Media|isbn=9781461553038|language=en}} and is simple to use.

Neutrophils and other phagocytes use peroxide to kill bacteria. The enzyme NADPH oxidase generates superoxide within the phagosome, which is converted via hydrogen peroxide to other oxidising substances like hypochlorous acid which kill phagocytosed pathogens.{{cite journal | vauthors = Winterbourn CC, Kettle AJ, Hampton MB | title = Reactive Oxygen Species and Neutrophil Function | journal = Annual Review of Biochemistry | volume = 85 | issue = 1 | pages = 765–792 | date = June 2016 | pmid = 27050287 | doi = 10.1146/annurev-biochem-060815-014442 }} In individuals with chronic granulomatous disease (CGD), phagocytic peroxide production is impaired due to a defective NADPH oxidase system. Normal cellular metabolism will still produce a small amount of peroxide and this peroxide can be used to produce hypochlorous acid to eradicate the bacterial infection. However, if individuals with CGD are infected with catalase-positive bacteria, the bacterial catalase can destroy the excess peroxide before it can be used to produce other oxidising substances. In these individuals the pathogen survives and becomes a chronic infection. This chronic infection is typically surrounded by macrophages in an attempt to isolate the infection. This wall of macrophages surrounding a pathogen is called a granuloma. Many bacteria are catalase positive, but some are better catalase-producers than others. Some catalase-positive bacteria and fungi include: Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E. coli, Staphylococcus, Serratia, B. cepacia and H. pylori.{{Cite book|title=First aid for the USMLE step 1 2017: a student-to-student guide |isbn=978-1-259-83762-3 |edition=27th |location=New York |publisher=McGraw-Hill Education |oclc=986222844| vauthors = Le T, Bhushan V, Sochat M, Kallianos K, Chavda Y, Zureick AH |date = 2017-01-06}}

Acatalasia is a condition caused by homozygous mutations in CAT, resulting in a lack of catalase. Symptoms are mild and include oral ulcers. A heterozygous CAT mutation results in lower, but still present catalase.{{cite web |title=OMIM Entry - # 614097 - ACATALASEMIA |url=http://www.omim.org/entry/614097 |website=www.omim.org |language=en-us}}

Low levels of catalase may play a role in the graying process of human hair. Hydrogen peroxide is naturally produced by the body and broken down by catalase. Hydrogen peroxide can accumulate in hair follicles and if catalase levels decline, this buildup can cause oxidative stress and graying.{{Cite web |title=Gray hair cure? Scientists find root cause of discoloration |url=http://www.nbcnews.com/healthmain/gray-hair-cure-scientists-find-root-cause-discoloration-6C9802771 |access-date=2022-07-31 |website=NBC News |date=6 May 2013 |language=en}} These low levels of catalase are associated with old age. Hydrogen peroxide interferes with the production of melanin, the pigment that gives hair its color.{{cite web | url = https://www.sciencedaily.com/releases/2009/02/090223131123.htm | title = Why Hair Turns Gray Is No Longer A Gray Area: Our Hair Bleaches Itself As We Grow Older | date = 2009-02-24 | work = Science News | publisher = ScienceDaily | access-date = 2009-03-01}}{{cite journal | vauthors = Wood JM, Decker H, Hartmann H, Chavan B, Rokos H, Spencer JD, Hasse S, Thornton MJ, Shalbaf M, Paus R, Schallreuter KU | title = Senile hair graying: H2O2-mediated oxidative stress affects human hair color by blunting methionine sulfoxide repair | journal = FASEB Journal | volume = 23 | issue = 7 | pages = 2065–2075 | date = July 2009 | pmid = 19237503 | doi = 10.1096/fj.08-125435 | doi-access = free | arxiv = 0706.4406 | s2cid = 16069417 }}

Catalase has been shown to interact with the ABL2{{cite journal | vauthors = Cao C, Leng Y, Kufe D | title = Catalase activity is regulated by c-Abl and Arg in the oxidative stress response | journal = The Journal of Biological Chemistry | volume = 278 | issue = 32 | pages = 29667–29675 | date = August 2003 | pmid = 12777400 | doi = 10.1074/jbc.M301292200 | doi-access = free }} and Abl genes. Infection with the murine leukemia virus causes catalase activity to decline in the lungs, heart and kidneys of mice. Conversely, dietary fish oil increased catalase activity in the heart, and kidneys of mice.{{cite journal |doi=10.1016/S0271-5317(00)00214-1 |title=Effects of dietary fish oil on tissue glutathione and antioxidant defense enzymes in mice with murine aids |journal=Nutrition Research |volume=20 |issue=9 |pages=1287–99 |year=2000 | vauthors = Xi S, Chen LH }}

In 1870, Schoenn discovered a formation of yellow color from the interaction of hydrogen peroxide with molybdate;{{Cite journal| vauthors = Isaacs ML |date=1922|title=A colorimetric determination of hydrogen peroxide|url=https://pubs.acs.org/doi/pdf/10.1021/ja01429a006|journal=Journal of the American Chemical Society|language=|volume=44|issue=8|pages=1662–1663|doi=10.1021/ja01429a006|bibcode=1922JAChS..44.1662I |s2cid= |issn=}} then, from the middle of the 20th century, this reaction began to be used for colorimetric determination of unreacted hydrogen peroxide in the catalase activity assay.{{Cite journal| vauthors = Peizer LR, Widelock D |date=1955|title=A colorimetric test for measuring catalase activity of cultures of M. tuberculosis|url=https://www.atsjournals.org/doi/abs/10.1164/artpd.1955.71.2.305 |journal= American Review of Tuberculosis|language=|volume=71|issue=2|pages=305–313|doi=10.1164/artpd.1955.71.2.305|doi-broken-date=1 November 2024 |pmid=14350192 |s2cid= |issn=}} The reaction became widely used after publications by Korolyuk et al. (1988){{cite journal | vauthors = Koroliuk MA, Ivanova LI, Maĭorova IG, Tokarev VE | title = [A method of determining catalase activity] | journal = Laboratornoe Delo | issue = 1 | pages = 16–19 | date = 1988 | pmid = 2451064 | url = https://pubmed.ncbi.nlm.nih.gov/2451064/ }} and Goth (1991).{{cite journal | vauthors = Góth L | title = A simple method for determination of serum catalase activity and revision of reference range | journal = Clinica Chimica Acta; International Journal of Clinical Chemistry | volume = 196 | issue = 2–3 | pages = 143–151 | date = February 1991 | pmid = 2029780 | doi = 10.1016/0009-8981(91)90067-m }} The first paper describes serum catalase assay with no buffer in the reaction medium; the latter describes the procedure based on phosphate buffer as a reaction medium. Since phosphate ion reacts with ammonium molybdate, the use of MOPS buffer as a reaction medium is more appropriate.{{cite journal | vauthors = Razygraev AV | title = Catalase enzymatic activity in adult mosquitoes (Diptera: Culicidae): taxonomic distribution of the continuous trait suggests its relevance for phylogeny research |url=https://www.mapress.com/zt/article/view/zootaxa.5339.2.3 | journal = Zootaxa | volume = 5339 | issue = 2 | pages = 159–176 | date = 2023 | pmid = 38221060| doi = 10.11646/zootaxa.5339.2.3 | s2cid = 261383164 }}

Direct UV measurement of the decrease in the concentration of hydrogen peroxide is also widely used after the publications by Beers & Sizer{{cite journal | vauthors = Beers RF, Sizer IW | title = A spectrophotometric method for measuring the breakdown of hydrogen peroxide by catalase | journal = The Journal of Biological Chemistry | volume = 195 | issue = 1 | pages = 133–140 | date = March 1952 | doi = 10.1016/S0021-9258(19)50881-X | pmid = 14938361 | doi-access = free }} and Aebi.{{cite book | vauthors = Aebi H | chapter = Catalase in vitro |title=Oxygen Radicals in Biological Systems | series = Methods in Enzymology | volume = 105 | pages = 121–126 | date = January 1984 | pmid = 6727660 | doi = 10.1016/s0076-6879(84)05016-3 | publisher = Academic Press | isbn = 9780121820053 }}

• Enzyme kinetics
• Glutathione peroxidase
• Peroxidase
• Superoxide dismutase

{{Reflist|35em}}

• {{cite web | url = http://genomics.senescence.info/genes/entry.php?hugo=CAT | title = GenAge entry for CAT (Homo sapiens) | publisher = Human Ageing Genomic Resources | access-date = 2009-03-05}}
• {{cite web | url = http://madsci.org/FAQs/catalase.html | title = Catalase | work = MadSci FAQ | publisher = madsci.org | access-date = 2009-03-05 | archive-date = 2009-03-09 | archive-url = https://web.archive.org/web/20090309011654/http://www.madsci.org/FAQs/catalase.html | url-status = dead }}
• {{cite web | url = http://www.tgw1916.net/video_pages/catalase.html | title = Catalase and oxidase test video | publisher = Regnvm Prokaryotae | access-date = 2009-03-05}}
• {{cite web | url = http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.6 | title = EC 1.11.1.6 - catalase | publisher = Brenda: The Comprehensive Enzyme Information System| access-date = 2009-03-05}}
• {{cite web|url=http://peroxibase.isb-sib.ch/ |title=PeroxiBase - The peroxidase database |publisher=Swiss Institute of Bioinformatics |access-date=2009-03-05 |url-status=dead |archive-url=https://web.archive.org/web/20081013084336/http://peroxibase.isb-sib.ch/ |archive-date=2008-10-13 }}
• {{cite web | url = http://microbeid.com/Methods/catalase.html | title = Catalase Procedure | publisher = MicrobeID.com | access-date = 2009-04-22}}
• {{cite web | url = http://www.rcsb.org/pdb/101/motm.do?momID=57.html | title = Catalase Molecule of the Month | publisher = Protein Data Bank | access-date = 2013-01-08 | url-status = dead | archive-url = https://web.archive.org/web/20130511202517/http://www.rcsb.org/pdb/101/motm.do?momID=57.html | archive-date = 2013-05-11 }}
• {{PDBe-KB2|P04040|Catalase}}

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