Organisation of enzyme structure and lysozyme example. Binding sites in blue, catalytic site in red and peptidoglycan substrate in black. (PDB: 9LYZ)
In biology and biochemistry, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of amino acid residues that form temporary bonds with the substrate, the binding site, and residues that catalyse a reaction of that substrate, the catalytic site. Although the active site occupies only ~10–20% of the volume of an enzyme,[1]: 19 it is the most important part as it directly catalyzes the chemical reaction. It usually consists of three to four amino acids, while other amino acids within the protein are required to maintain the tertiary structure of the enzymes.[2]
Each active site is evolved to be optimised to bind a particular substrate and catalyse a particular reaction, resulting in high specificity. This specificity is determined by the arrangement of amino acids within the active site and the structure of the substrates. Sometimes enzymes also need to bind with some cofactors to fulfil their function. The active site is usually a groove or pocket of the enzyme which can be located in a deep tunnel within the enzyme,[3] or between the interfaces of multimeric enzymes. An active site can catalyse a reaction repeatedly as residues are not altered at the end of the reaction (they may change during the reaction, but are regenerated by the end).[4] This process is achieved by lowering the activation energy of the reaction, so more substrates have enough energy to undergo reaction.
^Bugg TD (2004). Introduction to Enzyme and Coenzyme Chemistry(PDF) (2nd ed.). Blackwell Publishing Limited. ISBN 9781405114523. Archived from the original (PDF) on 22 March 2018.
^Shanmugam S (2009). Enzyme Technology. I K International Publishing House. p. 48. ISBN 9789380026053.
biochemistry, the activesite is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The activesite consists of amino...
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a site other than the enzyme's activesite. The site to which the effector binds is termed the allosteric site or regulatory site. Allosteric sites allow...
enzyme's activesite. The remaining majority of the enzyme structure serves to maintain the precise orientation and dynamics of the activesite. In some...
facilitates a specific chemical reaction by binding the substrate to its activesite, a specialized area on the enzyme that accelerates the most difficult...
make glucose-6-phosphate. Activesite residues of hexokinase allow for stabilization of the glucose molecule in the activesite and spur the onset of an...
Mg2+ in the activesite of the enzyme involves addition of an "activating" carbon dioxide molecule (CO2) to a lysine in the activesite (forming a carbamate)...
repeating α-β subunits, each coupled pair of subunits has an activesite, for a total of 12 activesites. It plays an essential function for survival, neutralizing...
tissues of the body but are at the highest concentration in the liver. The activesite of the aldehyde dehydrogenase enzyme is largely conserved throughout...
into one of several families based on their activesite mechanism. Enzymes that use a metal in the activesite are called "metallo-carboxypeptidases" (EC...
dissociated ions of carbonic acid (i.e. bicarbonate and hydrogen ions). The activesite of most carbonic anhydrases contains a zinc ion. They are therefore classified...
(not shown here) in the activesite. The amino acids are shown as wires, and the TPP is in ball and stick form. The activesite also aids in the transfer...
requirement for L-DOPA as cofactor. The two copper atoms within the activesite of tyrosinase enzymes interact with dioxygen to form a highly reactive...
IDH has two activesites. Each activesite binds a NAD+/NADP+ molecule and a divalent metal ion (Mg2+,Mn2+). In general, each activesite has a conserved...
newer class of medication, directly inhibit thrombin by binding to its activesite. Recombinant thrombin is available as a powder for reconstitution into...
while within the activesite (e.g. hydrogen bonding or van der Waals forces). Specific and favorable bonding occurs within the activesite until the substrate...
substrate. This is accomplished by blocking the binding site of the substrate – the activesite – by some means. The Vmax indicates the maximum velocity...
heterogeneous catalyst has activesites, which are the atoms or crystal faces where the substrate actually binds. Activesites are atoms but are often described...
has two zinc atoms per subunit. One is the activesite, which is involved in catalysis. In the activesite, the ligands are Cys-46, Cys-174, His-67, and...
Cre does not form a shared activesite between separate subunits and all the residues that contribute to the activesite are found on a single subunit...
work has shown that there are no ribosomal proteins close to the reaction site for polypeptide synthesis. This suggests that the protein components of ribosomes...
attack the C-2 cation which will leave behind a fructose molecule. The active-site carboxylate anion will take action to help keep the unequal balance of...
acetyl-CoA. Pyruvate decarboxylase occurs as a dimer of dimers with two activesites shared between the monomers of each dimer. The enzyme contains a beta-alpha-beta...
Pepsin is an aspartic protease, using a catalytic aspartate in its activesite. It is one of three principal endopeptidases (enzymes cutting proteins...
group of the amino acid substrate displaces the ε-amino group of the active-site lysine residue in a process known as transaldimination. The resulting...
site contains a water molecule or a dioxygen molecule. By contrast the protein myoglobin, found in muscle cells, has only one such unit. The active site...
made of seven β subunits that contain three to seven protease activesites. These sites are located on the interior surface of the rings, so that the...
at the activesite. Partial denaturation actually improves hemocyanin's phenol oxidase activity by providing greater access to the activesite. Spectroscopy...
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