Papaya latex Chymopapain

In 198ft, Loozeet al. published a series of articles on the cysteine proteinases from papaya latex. In the first article, they described an alternative way to purify chymopapain and papaya proteinase El to homogeneity [32], In the following articles die primary structures of chymopapain [33] and papaya proteinase 2 [34] were described (Fig. ). The primary structure of chymopapain determined by Wblson et al. [35] is in perfect agreement with the results of Dubois ct al. 

The residues in the Sj subsite that make the most intimate contact are those of Val-133, Val-157, Ala-160, Pro-68, and iyr-67. In the four enzymes of the papaya latex, ail incite groups remain hydrophobic, wiui the exception of Pro-68, which is replaced by Olu in chymopapain and in gtycyl endopeptidase. The nonpolar character, and generally specificity, of the S2 subsite would therefore be conserved. 

In addition to papain, at least two other proteolytic components have been shown to be present in crude extracts of commercial papaya latex, namely, chymopapain (1,27) and papaya peptidase A (28). Since these isolated enzymes are not used commercially, they will not be considered further. 

To date, the latex of Carica papaya L. is known to contain at least four different proteolytic enzymes, namely, papain (E.C. 3.4.22.2), chymopapain (E.C. 3.4.22.6), caricain or papaya proteinase III or 2 (E.C. 3.4.22.30), and glycyl endopeptidase or papaya proteinase IV (E.C. 3.4.22.25). The importance of the latex of the unripe fruit of the tropical tree Carica papaya L. was first noted by G. C. Roy, who in 1873 published in the Calcutta Medical Journal (see Ref. 1) an article entitled The solvent action of papaya juice on the nitrogenous articles of food. The name papain was used for the first time by Wurtz and Bouchet [2] to describe partially purified cysteine proteinases from the papaya latex. They wrote, nous designerons ce ferment sous le nom de papa ine." In 1880, Wurtz postulated that papain acts in fibrin digestion by becoming bound to the fibrin [3]. This is remarkable in that Emil Fisher first described the specific association of enzyme with substrate in 1898. Since that time, many names have been used for commercial latex products, e.g., papayotin, papaoid, etc. 

In 1988, Looze et al. published a series of articles on the cysteine proteinases from papaya latex. In the first article, they described an alternative way to purify chymopapain and papaya proteinase Q to homogeneity [32], In the following articles the primary structures of chymopapain [33] and papaya proteinase 12 [34] were described (Fig. 1). The primary structure of chymopapain determined by Watson et al. [35] is in perfect agreement with the results of Dubois et al. Jacquet et al. described the proteolytic specificities of chymopapain and papaya proteinase 12 [36]. The polypeptide chain of caricain contains 216 amino acid residues (Mr 23283). The molecule shares 148 identical amino acid residues (68.5%) with papain, 141 with chymopapain (65.2%), and 175 with glycyl endo-peptidase (81.0%). The Ai%,280nm is 18.3 [20]. The three-dimensional structure of caricain has been determined by x-ray diffraction analysis [37,38]. 

E. F. Jansen and A. K. Balls. Chymopapain a new crystalline proteinase from papaya latex. J. Biol. Chem. 137 459 (1941). 

An ethnobotanical survey indicated that papaya leaf, fruit, and root are used in Uganda to induce labor (Kamatenesi-Mugisha and Oryem-Origa 2007). In isolated rat uteruses, papaya latex and the compounds papain and chymopapain induced spasmodic contraction of the uterine muscles (Adaikan and Adebiyi 2004 Adebiyi et al. 2002). 

Chymopapain [9001 -90-6] derived from the latex of the papaya tree, produces improvement in lower back pain and sciatica in the majority (75%) of recipients (185—189) when injected into the lumbar intervertebral disks of patients suffering from herniated disk (the nucleus pulposus). This treatment degrades the proteoglycans of the diseased nucleus pulposus, resulting in shrinkage of the disk and reduction of pressure on the nerve roots (190). 

A. Jacquet, T, Kkutschmidt, A. G. Schnek, Y. Looze, and G. Biamrifeer. The thiol proteinases from the latex of Carica papaya L. Ill, Hie primary structure of chymopapain, BioL Chan. Hoppe-Seyier 370 425 (1989). 

B. S. Baines and K. Brocklehurst. Isolation and characterization of the four major cysteine-proteinase components of the latex of Carica papaya L. Reactivity characteristics towards 2,2 -dipyridyl disulfide of the thiol groups of papain, chymopapains A and B, and papaya peptidase A. J. Protein Chem. 7 119 (1982). 

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