Title: Papain
CAS Registry Number: 9001-73-4
Synonyms: Papayotin; vegetable pepsin
Trademarks: Arbuz; Nematolyt; Summetrin; Tromasin; Velardon (Organon); Vermizym
Literature References: First recognized member of the class of proteolytic enzymes that needs a free sulfhydryl group for activity. Isolated from the latex of the green fruit and leaves of
Carica papaya L.,
Caricaceae. Initial isolation and crystallization: Balls
et al., Science 86, 379 (1937); Balls, Lineweaver,
J. Biol. Chem. 130, 669 (1939). Prepn from commercial dried papaya latex and physical properties: Kimmel, Smith,
ibid. 207, 515 (1954);
see also ibid. 533-573; Becker,
Econ. Bot. 12, 62 (1958). Purification: Gibian, Bratfisch,
US 2950227 (1960 to Schering AG); Lesuk,
US 3011952 (1961 to Sterling Drug); Blumberg
et al., Eur. J. Biochem. 15, 97 (1970). The papain molecule consists of one folded polypeptide chain of 212 residues, mol wt ~23,400. Complete amino acid sequence: Drenth
et al., Nature 218, 929 (1968); Mitchel
et al., J. Biol. Chem. 245, 3485 (1970). Mechanism of action studies: Morihara,
J. Biochem. 62, 250 (1967). Use in treatment of contact lenses to prolong wearing time in keratoconic patients with papillary conjunctivitis: D. R. Korb
et al., Arch. Ophthalmol. 101, 48 (1983).
Reviews: Kimmel, Smith in
Adv. Enzymol. Relat. Subj. Biochem. 19, 267-334 (1957); Glazer, Smith in
The Enzymes vol. III, P. D. Boyer, Ed. (Academic Press, New York, 3rd ed., 1971) pp 501-537;
see also Drenth
et al., ibid. 485-498 and
eidem, Adv. Protein Chem. 25, 79-115 (1971) for a comprehensive review of the structural elucidation.
Properties: White or grayish-white, slightly hygroscopic powder. uv max: 278 nm (A1%1cm 25.0). Incompletely sol in water, glycerol. Practically insol in most organic solvents.
Keep well closed. Potency varies according to process of prepn, etc. with the usual grade digesting ~35 times its wt of lean meat. Best grades render sol 200-300 times their wt of coagulated egg albumin in alkaline media. A temp. range of 60-90° is favorable for the digestive process with 65° the optimum point. Best pH is 5.0, but it functions also in neutral or alkaline media. Activated by reduction (HCN, H2S etc.) and inactivated by oxidation (H2O2, iodoacetate).
Absorption maximum: uv max: 278 nm (A1%1cm 25.0)
NOTE: The term papain is currently applied to both the crude dried latex and the crystalline proteolytic enzyme.
Use: For tenderizing meats; for clearing beverages; for bating skins.
Therap-Cat: Enzyme (proteolytic). Debriding agent; digestive aid. Has been used to prevent adhesions; as anthelmintic (Nematodes).
Keywords: Anthelmintic (Nematodes); Debriding Agent; Digestive Aid; Enzyme; Proteolytic.
