View source for Hydrolase

{{Short description|Class of enzymes which use water to break a chemical bond}}
{{Distinguish|hydroxylase}}
In [[biochemistry]], '''hydrolases''' constitute a class of [[enzyme]]s that commonly function as biochemical [[catalyst]]s that use water to [[Bond cleavage|break]] a [[chemical bond]]:

:<math chem>\ce{A-B + H2O} \quad \xrightarrow[\text{ hydrolase }]{} \quad \ce{A-OH + B-H}</math>

This typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are [[esterase]]s including [[lipase]]s, [[phosphatase]]s, [[Glycoside hydrolase|glycosidases]], [[Protease|peptidases]], and [[Purine nucleoside phosphorylase|nucleosidases]].

Esterases cleave ester bonds in [[lipid]]s and phosphatases cleave [[phosphate group]]s off molecules. An example of crucial esterase is [[acetylcholine esterase]], which assists in transforming the neuron impulse into the [[Acetate|acetate group]] after the hydrolase breaks the [[acetylcholine]] into [[choline]] and [[acetic acid]].<ref name=":0"/> Acetic acid is an important metabolite in the body and a critical intermediate for other reactions such as [[glycolysis]]. Lipases hydrolyze [[glyceride]]s. Glycosidases cleave sugar molecules off carbohydrates and peptidases hydrolyze [[peptide bond]]s. Nucleosidases hydrolyze the bonds of [[nucleotide]]s.<ref>{{Cite web |date=9 April 2018 |title=hydrolase {{!}} class of enzymes {{!}} Britannica |url=https://www.britannica.com/science/hydrolase |access-date=29 April 2017 |website=www.britannica.com |language=en}}</ref>

Hydrolase enzymes are important for the body because they have degradative properties. In lipids, lipases contribute to the breakdown of fats and lipoproteins and other larger molecules into smaller molecules like fatty acids and [[glycerol]]. Fatty acids and other small molecules are used for synthesis and as a source of energy.<ref name=":0">{{Cite web|url=http://www.chemistryexplained.com/Ge-Hy/Hydrolase.html|title=Hydrolase - Chemistry Encyclopedia - water, examples, molecule|website=www.chemistryexplained.com|language=en|access-date=2018-04-29}}</ref>

==Nomenclature==
Systematic names of hydrolases are formed as "[[Enzyme substrate|substrate]] hydrolase." However, common names are typically in the form "''substrate base''". For example, a [[nuclease]] is a hydrolase that cleaves [[nucleic acid]]s.

==Classification==
Hydrolases are classified as '''EC 3''' in the [[Enzyme Commission number|EC number]] classification of enzymes. Hydrolases can be further classified into several subclasses, based upon the bonds they act upon:
*[[:Category:EC 3.1|EC 3.1]]: [[ester]] bonds ([[esterase]]s: [[nuclease]]s, [[phosphodiesterase]]s, [[lipase]], [[phosphatase]])
*[[:Category:EC 3.2|EC 3.2]]: sugars ([[DNA glycosylase]]s, [[glycoside hydrolase]])
*[[:Category:EC 3.3|EC 3.3]]: [[ether]] bonds
*[[:Category:EC 3.4|EC 3.4]]: [[peptide bond]]s ([[protease|Proteases/peptidase]]s)
*[[:Category:EC 3.5|EC 3.5]]: [[carbon-nitrogen bond]]s, other than peptide bonds
*[[:Category:EC 3.6|EC 3.6]] [[acid anhydride]]s ([[acid anhydride hydrolases]], including [[helicase]]s and [[GTPase]])
*[[:Category:EC 3.7|EC 3.7]] [[carbon-carbon bond]]s
*[[:Category:EC 3.8|EC 3.8]] [[halide]] bonds
*[[:Category:EC 3.9|EC 3.9]]: phosphorus-nitrogen bonds
*[[:Category:EC 3.10|EC 3.10]]: sulphur-nitrogen bonds
*[[:Category:EC 3.11|EC 3.11]]: [[Organophosphate|carbon-phosphorus bond]]s
*[[:Category:EC 3.12|EC 3.12]]: sulfur-sulfur bonds
*[[:Category:EC 3.13|EC 3.13]]: [[Organosulfur compounds|carbon-sulfur bond]]s

==Clinical considerations==
Hydrolase secreted by ''[[Lactobacillus jensenii]]'' in the [[Upper gastrointestinal tract|human gut]] stimulates the [[liver]] to secrete [[bile salts]] that aids in the digestion of food.<ref name="PrinceAntony2014">{{cite journal|last1=Prince|first1=Amanda L.|last2=Antony|first2=Kathleen M.|last3=Chu|first3=Derrick M.|last4=Aagaard|first4=Kjersti M.|title=The microbiome, parturition, and timing of birth: more questions than answers|journal=Journal of Reproductive Immunology|volume=104-105|year=2014|pages=12–19|issn=0165-0378|doi=10.1016/j.jri.2014.03.006| pmid= 24793619 |pmc= 4157949 }}</ref>

==Membrane-associated hydrolases==
Many hydrolases, and especially [[protease]]s associate with [[biological membranes]] as [[peripheral membrane protein]]s or anchored through a single [[transmembrane helix]].<ref>{{Cite web |date=July 2018 |title=Superfamilies of single-pass transmembrane hydrolases |url=https://membranome.org/protein_classes/11 |url-status=live |archive-url=https://web.archive.org/web/20220308072328/https://membranome.org/protein_classes/11 |archive-date=8 March 2022 |access-date=23 July 2018 |website=membranome.org}}</ref> Some others are multi-span [[transmembrane proteins]], for example [[rhomboid protease]].

==Etymology and pronunciation==
The word ''hydrolase'' ({{IPAc-en|ˈ|h|aɪ|d|r|oʊ-|l|eɪ|s|,_|-|l|eɪ|z}}) suffixes the [[classical compound|combining form]] of ''[[wikt:-ase#Suffix|-ase]]'' to the ''hydrol'' syllables of ''[[hydrolysis]]''.

==See also==
{{Portal|Biology}}
*[[Phosphorylase]]
*[[Serine hydrolase]]
*[[Cadmium-transporting ATPase]]

==References==
{{Reflist}}
* [https://web.archive.org/web/20110709034550/http://www.chem.qmul.ac.uk/iubmb/enzyme/EC3/intro.html EC 3 Introduction] from the Department of Chemistry at [[Queen Mary, University of London]], covers only 3.1-3.4
* [https://web.archive.org/web/20121122050446/http://www.chem.qmul.ac.uk/iubmb/enzyme/EC3/ More detailed taxonomy]

{{Enzymes}}
{{Hydrolases}}

[[Category:Hydrolases| ]]