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1. SUBMITTED BY :
SASHI BHUSAN
TRIPATHY

2. Papaya
• Papaya (Carica papaya L.) is a popular fruit
native to tropical America.
• It is usually grown for its small to large melon-
like fruit.
• It is a herbaceous perennial, bearing fruit
continuously at the leaf axils spirally arranged
along the single erect trunk .

3. PAPAIN
• Papain is a proteolytic enzyme extracted from
the milky latex obtained from immature
papaya.
• About 400 tons of papain is produced
throughout the world.
• The USA and UK are the major consumers of
papain.

4. PROCEDURE OF EXTRACTION:
• The immature fruits of 90-100 days old are
used for extraction of milky latex by giving 4-6
cuts of about 2mm depth, the latex is
collected from 5-6 tapping and sieved the
latex and dried in sun or in vacuum shelf dryer.
• The quality and grade of papain is determined
by colour and enzyme activity (Tyrosine unit).

5. Some of the important points to be
considered while collecting the latex.
• Fruits of 90-100 days from fruit set are
generally preferred.
• Oblong fruits relatively yield more yielder than
round ones.
• Fruits set during July yield more papain.
• There will be a 4 fold increase in papain yield
by using ethrel at 200 ppm.

6. CONTINUED:-
• Always collect the papain in glass vessels or
Aluminum trays.
• Use Potassium Metabisulphite (0.05 per cent)
to extend the storage life
• About 450g/plant and 250-375 kg papain
could be extracted from an hectare area. The
varieties C0-5 and C0-2 are preferred for
papain extraction.

7. SUITABLE VERITY OF PAPAYA
• Co-5: Selection from Washington and the
plants are exclusively selected for papain
extraction and yields about 14-15 g. of
papain/fruit, Yields 100-220 tons/ha.

8. Enzymatic Reaction
• Papain is a cysteine hydrolase that is stable and active
under a wide range of conditions. It is very stable even
at elevated temperatures.
• The latex of Carica papaya is a rich source of four
cysteine endopeptidases including papain,
chymopapain, glycyl endopeptidase, and caricain.
• The proteins are synthesized as inactive precursors
that become active within two minutes of the plant
being wounded and the latex expelled.
• Papain is a minor constituent, but has been more
widely studied because it is more easily purified
(Azarkan 2003)

9. Specificity
• Papain has fairly broad specificity; it has endopeptidase,
amidase, and esterase activities.
• The active site consists of seven subsites (S1-S4 and S1’-S3’)
that can each accommodate one amino acid residue of a
substrate (P1-P4 and P1’-P3’).
• Specificity is controlled by the S2 subsite, a hydrophobic
pocket that accommodates the P2 side chain of the
substrate.
• Papain exhibits specific substrate preferences primarily for
bulky hydrophobic or aromatic residues at this subsite .
• Outside of the S2 subsite preferences, there is a lack of
clearly defined residue selectivity within the active site .

10. Molecular Characteristics
• The mature forms of all papaya proteinases are
between 212 and 218 amino acids, and exhibit a
strong degree of homology . X-ray structure
analysis has shown that they adopt identical
three-dimensional folds.
• Papain is synthesized as a zymogen with a 133
amino acid N-terminal region that is not part of
the active enzyme. The papain precursor gene,
prepropapain, has been cloned and expressed
either in parts or as a whole .

11. COMPOSITION:
• Papain is a single-chained polypeptide with three
disulfide bridges and a sulfhydryl group necessary
for the activity of the enzyme.
• Papain is expressed as an inactive precursor,
prepropapain.
• The formation of active papain requires several
cleavage steps including an initial cleavage of the
18 amino acid preregion (the signal sequence),
followed by further cleavage of the glycosylated
114 amino acid proregion .

12. MEAT TENDERIZING ENZYMES, A BRIEF
DISCUSSION
• Papain is usually produced as a crude, dried material by
collecting the latex from the fruit of the papaya tree.
• The latex is collected after scoring the neck of the fruit
whereupon it may either dry on the fruit or drip into a
container.
• This latex is then further dried. It is now classified as a
dried, crude material. A purification step is necessary to
remove contaminating substances.
• This purification consists of the solubilization and
extraction of the active papain enzyme system through a
government registered process. This purified papain may
be supplied as dried powder or as a liquid.

13. APPLICATION
• Cell isolation where it is more gentle than other
proteases (i.e.: cortical neurons, retina, and smooth
muscle)
• Protein structural studies, peptide mapping
• Red cell surface modification for antibody screening or
identification
• Fab preparation from IgG and IgM antibodies
• Solubilization of integral membrane proteins
• Production of glycopeptides from purified
proteoglycans
• Enzymatic wound debridement