Papaya papain

Modification of the proteins by addition of proteolytic enzymes prevents the precipitation of the peptides upon chilling. Proteases from papaya (papain) were already applied in 1911. It is even more remarkable that the major chill stabilizing enzyme used today is still papain. 

Papain, EC 3.4.22.2, the archetype of cysteine peptidases. It was isolated from the latex of the tropical papaya fruit (Carica papaya). Papain is a single-chain protein (212 aa 23 kDa) containing three disulfide bonds and a known three-dimensional structure with 1.65 A resolution The catalytic amino acid residues have been identified as Cys, His and Asn, whereas Gln helps to stabilize the oxyanion hole. Papain has a fairly broad specificity [J. R. Kimmel, E. L. Smith, J. Biol. Chem. 1954, 207, 515 A. C. Storer, R. Menard, Methods Enzymol. 1994, 244, 486]. 

Homologues of the classical papaya papain that have been tested for peptide S5mthesis are plant-derived enzymes such as bromelain and ficain. Bromelain extracted from pineapple could be applied in Met- and Leu-enkephalin synthesis in a low water system, reaching 97% yield [27]. Ficain isolated from Ficus glabrata latex was tested in di- and tripeptide synthesis in frozen water medium [23] and was used in the synthesis of Lys and Met oligomers starting from the respective ethyl esters [29]. 

FIGURE 14.11 The pH activity profiles of four different enzymes. Trypsin, an intestinal protease, has a slightly alkaline pH optimnm, whereas pepsin, a gastric protease, acts in the acidic confines of the stomach and has a pH optimmn near 2. Papain, a protease found in papaya, is relatively insensitive to pHs between 4 and 8. Cholinesterase activity is pH-sensitive below pH 7 but not between pH 7 and 10. The cholinesterase pH activity profile suggests that an ionizable group with a pK near 6 is essential to its activity. Might it be a histidine residue within the active site ... 

Different enzymes have different specificities. Some, such as amylase, are specific for a single substrate, but others operate on a range of substrates. Papain, for instance, a globular protein of 212 amino acids isolated from papaya fruit, catalyzes the hydrolysis of many kinds of peptide bonds. In fact, it s this ability to hydrolyze peptide bonds that makes papain useful as a meat tenderizer and a cleaner for contact lenses. 

Proteolytic enzyme from the latex of Carica papaya with an approximate molecular weight of 27000. It is differentiated from papain in electrophoresis behavior, in solubility and in substrate specifity. Isolation by acidify of papaya-latex with HCl, salting out with NaCl and following chromatographic purification. The formulation contains L-cysteine as reducing agent. 

Papain is a cysteine protease isolated from the latex of the immature fruit and leaves of the plant Carica papaya. It consists of a single 23.4 kDa, 212 amino acid polypeptide, and the purified enzyme exhibits broad proteolytic activity. Although it can be used as a debriding agent, it is also used for a variety of other industrial processes, including meat tenderizing and for the clarification of beverages. 

This enzyme [EC 3.4.22.6], also known as papaya proteinase II, is a member of the peptidase family Cl. It is the major endopeptidase of papaya (Carica papaya) latex. It has a specificity similar to that of papain. In addition, there are a number of chromatographic forms of the enzyme. 

This enzyme [EC 3.4.22.25] catalyzes the hydrolysis of peptide bonds with a preference for Gly-Xaa in proteins and small molecule substrates. The enzyme, a member of the peptidase family Cl, is isolated from the papaya plant, Carica papaya. It is not inhibited by chicken cys-tatin, unlike most other homologs of papain. 

This is a papaya enzyme available over the counter. It is not known whether this does anything. Dr. Grow said that Papain is an antibody to THC, and in theory may destroy THC when added to the urine sample. However, positive urine doesn t actually contain THC it contains THC byproducts. Papain has not been tested, and may or may not work. 

Brocklehurst, K., Carlsson, J., Kierstan, M.P.J, and Crook, E.M., Covalent chromatography. Preparation of fully active papain from dried papaya latex, Biochem. J., 133, 573-584, 1973. 

Proteins free-sulfvdrvl papain and chymopapain (papaya, Carica papaya L., Violales, Ang. native to S Amwica, cultivated in Zaire, Uganda, Tanzania, and the East) and brcmelain (pineapple. Ananas comosum, Bromeliales, Ang. native to S America, cultivated in Africa) NO-releasing heme nitrqjhwin (blood-sucking Ins. Rhodnius prolixux Walker 1999). 

Papain—a plant protease derived from the papaya fruit. The enzyme is used in digestive aids, wound debridement, tooth-cleaning and. most importantly, as a meat tenderizer. 

Papain Hydrolysis of proteins Papaya fruit (Carica Meat tenderizer ... 

Papain is a mixture of proteolytic enzymes found in extract of papaya, the fruit of the papaya tree (Carica papaya). It is taken orally in the belief that it reduces edema, inflammation, herpes zoster symptoms, diarrhea, and psoriasis symptoms. The pharmacological mechanisms by which papain may affect coagulation are not known. Patients receiving warfarin should be advised to avoid papain supplementation until further information about this potential interaction becomes available (Table 4.4). 

Papayas contain papain, an enzyme that is similar to the digestive juice pepsin. Because this enzyme breaks down protein, papain extract from papayas is marketed as a meat... 

Crude papain, obtained as the dried exudate of the fruit and leaves of Carica papaya L., Caricaceae, is usually found to have been contaminated during collection, drying, or storage by insects, rodent hair and excreta, botanical plant parts, sand, etc. and may thereby become further contaminated by harmful bacteria and enteric organisms. 

The interest in papain increased enormously after the publication by Kimmel and Smith D ] of a modification of the purification procedure of Balls and Lineweaver [5j. This modification permitted the isolation of pure papain from papaya dried latex and was used for many years as the standard method for the production of papain. The crystalline papain of Kimmel and Smith consists of three components active papain, reversibly oxidized papain, and irreversibly oxidized papain. Reversibly oxidized papain can be converted into active papain by reduction of the active-site thiol by low molecular weight thiols [10], sodium borohydride [11], or CN [12]. In active papain, the Cys-25, which is essential far catalytic activity, is present in a reduced form, while in reversibly oxidized papain the Cvs-25 forms a mixed disulfide with cysteine. Drenth et al. reported that in irreversibly oxidized papain the Cys-25 has been oxidized to the sulfuric acid... 

Jacquct et al. described the proteolytic specificities of chymopapain and papaya proteinase Q [36]. The polypeptide chain of caricain contains 216 amino acid residues (Mr 23283). The molecule shares 148 identical amino acid residues (68,5ft) with papain. 141 with chymopapain (65,2ft), and 175 with glycyl endopeptidase (81.0ft). The Ms,lllOnin is 1U [20]. The three-dimensional structure of caricain has been determined by x-ray diffraction analysis [37,38]-... 

El is well known that the cysteine proteinase of the papaya latex differ in their ability to hydrolyze proteins and synthetic peptides. Schechter and Beiger [67] first demonstrated that the landing regions in the active center of proteinases can be divided into different subtitles, of whidi die Sz subsite seems to be the most important in papain. 

Crude papaya latex, usually called papain, has found a number of industrial applications. It has been used in brewing, meat tenderization, flavor production. 

A, K. Balls and R Linewcaver, Isolation and properties of crystalline papain. J. BioL E. F.lamen and A. K. Balk. Chymopapain a new crystalline proteinase from papaya... 

B. S. Baines and K. Brocklchurat A necessary modification to die preparation of papain from any high-quality latex of Carica papaya and evidence for the structural integrity of the enzyme produced by traditional methods. Biochem. J. 177)541 (1979). 

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