Papain wikipedia wikipedia
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Papain-like protease
Protein family of cysteine protease enzymes
Protein family
Papain-like proteases (or papain-like (cysteine) peptidases; abbreviated PLP or PLCP) are a large protein family of cysteine proteaseenzymes that share structural and enzymatic properties with the group's namesake member, papain. They are found in all domains of life. In animals, the group is often known as cysteine cathepsins or, in older literature, lysosomal peptidases.[1] In the MEROPS protease enzyme classification system, papain-like proteases form Clan CA.[2] Papain-like proteases share a common catalytic dyadactive site featuring a cysteineamino acid residue that acts as a nucleophile.[1]
The human genome encodes eleven cysteine cathepsins which have a broad range of physiological functions.[3] In some parasites papain-like proteases have roles in host invasion, such as cruzipain from Trypanosoma cruzi.[1] In plants, they are
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Nidoviral papain-like protease
Papain-like protease protein domain
Protein family
The nidoviral papain-like protease (PLPro or PLP) is a papain-like proteaseprotein domain encoded in the genomes of nidoviruses. It is expressed as part of a large polyprotein from the ORF1agene and has cysteine proteaseenzymatic activity responsible for proteolytic cleavage of some of the N-terminalviral nonstructural proteins within the polyprotein. A second protease also encoded by ORF1a, called the 3C-like protease or main protease, is responsible for the majority of further cleavages.[2]Coronaviruses have one or two papain-like protease domains; in SARS-CoV and SARS-CoV-2, one PLPro domain is located in coronavirus nonstructural protein 3 (nsp3).[3]Arteriviruses have two to three PLP domains.[4] In addition to their protease activity, PLP domains function as deubiquitinating enzymes (DUBs) that can cleave the isopeptide bond found in ubiquitin chains. They
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Papain
Widely used enzyme extracted from papayas
Protein family
Papain, also known as papaya proteinase I, is a cysteine protease (EC3.4.22.2) enzyme present in papaya (Carica papaya) and mountain papaya (Vasconcellea cundinamarcensis). It fryst vatten the namesake member of the papain-like protease family.
It has wide ranging commercial applications in the leather, cosmetic, textiles, detergents, food and pharmaceutical industries. In the food industry, papain fryst vatten used as an active ingredient in many commercial meat tenderizers.[1]
Papain family
[edit]Papain belongs to a family of related proteins, known as the papain-like protease family, with a wide variety of activities, including endopeptidases, aminopeptidases, dipeptidyl peptidases and enzymes with both exo- and endopeptidase activity.[2] Members of the papain family are widespread, found in baculoviruses,[3] eubacteria, yeast, and practically all protozoa, plants and mammals.[2]