For B.Pharm, 4th sem

1. Proteolytic Enzymes

2. Proteolytic Enzymes
 Enzymes involved in degradation of
proteins are called as proteases or
proteolytic enzymes
 Industrially available proteolytic enzymes
produced by microorganisms are usually
mixtures of endopeptidases and
exopeptidases.
 Proteins Polypeptides
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Endopeptidases
Exopeptidases

3. Cont …
 Because of the complex structures and high
molecular weights of proteins enzymic proteolysis
is extremely complicated.
 Most proteases are quite specific with regard to
which peptide linkages they can split
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4. List of proteolytic enzymes
a. Papain
b. Ficain
c. Bromelain
d. Pepsin
e. Rennin
f. Cathepsin
g. Trypsin
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5. A) Papain
◦ Found in papaya
◦ papain, also known as papaya proteinase I
◦ Broad pH (3-11) and temperature stability
 For this reason very popular for a variety of food
applications.
1. Used as a meat tenderizer on inferior meat cuts (can also use
slice of pineapple on meat)
 The enzyme makes its way into the muscle and
hydrolyzes primarily connective tissue proteins (collagen
etc.) and softens muscle
 Have to use low amount to prevent liquefaction of
muscle
 If you mix raw papaya into Jell-O it will not form a gel

6. Application of papain
 Meat Tenderizer- Papain ( a protease
found in papaya) is used as meat
tenderizer to soften meat for cooking

7. Cont…
 Papain can be used to dissociate cells
in the first step of cell
culture preparations.
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8. Ficain
 Ficain also known as
ficin is an enzyme that is derived
from figs latex
 It is of a family of proteases known as
the cysteine endopeptidases
 It is one of the most commonly used for
differentiating many blood group antigens
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9. Bromelain
 Bromelain is an enzyme generally found in the
stems and fruits of pineapples.
 According their sources enzymes are divided into
A. Stem bromelain.
B. Fruit bromelain.
 The proteolytic enzymes are sulfhydryl proteases,
since a free sulfhydryl group of a cysteine side
chain is required for function
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10.  Bromelain is present in all parts of the
pineapple plant but the stem is the
most common commercial source
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11. Applications of bromelain
 Along with papain, bromelain is one of the most
popular proteases to use for meat tenderizing
 Cooked pineapple does not have a tenderizing
effect, as the enzymes are heat-labile
 Preparation of meat balls
 Systemic enzyme therapy (combinations of
proteolytic enzymes such as bromelain, trypsin and
papain) has been used in the treatment of breast
cancer
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12. Pepsin
 Pepsin is an enzyme whose zymogen (pepsinogen) is
released by the chief cells in the stomach and that degrades
food proteins into peptides
 It was discovered by Theodor Schwann who also coined its
name from the Greek word pepsis, meaning "digestion
 Pepsin is one of three principal protein-degrading enzyme in
the digestive system, the other two
being chymotrypsin and trypsin
 Pepsin is most efficient in cleaving peptide bonds and
preferably breaks at aromatic amino acids such
as phenylalanine, tryptophan, and tyrosine
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13. Cont…
 Pepsin is most active in acidic environments Pepsin exhibits
maximal activity at pH 2.0 and is inactive at pH 6.5
 In most cases Pepsinogen is activated by HCl
 Pepsins should be stored at very low temperatures (between
−80 °C and −20 °C) to prevent autolysis (self-digestion
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14. Applications of pepsin
 Pepsin is commonly used in the
preparation of F(ab')2 fragments from
antibodies
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15. Cont…
 Powder of pepsin is often used as a
dietary supplement to aid digestion
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16. Rennin
 Rennin or Chymosin is a protease produced by
newborn ruminant in the fourth stomach to curdle the milk
they ingest
 The native substrate of Chymosin is K-casein cleavaes at
amino acids like phenylalanine and methionine
 Bovine chymosin is now produced recombinantly in E.
coli, Aspergillus niger alternative resource.
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17. Application of rennin
 It is widely used in the production
of cheese
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18. Cathepsin
 Cathepsins are proteases that degrade proteins)
found in all animals as well as other organisms.
 Enzyme cathepsins found only in the lysosome
 Most of the members become activated at the low
pH found in lysosomes
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19. Cont….
 There are approximately a dozen members
of this family, which are distinguished by
their structure
 Cathepsin A (serine protease)
 Cathepsin B (cysteine protease)
 Cathepsin C (cysteine protease)
 Cathepsin D (aspartyl protease)
 Cathepsin E (aspartyl protease)
 Cathepsin F (cysteine proteinase)
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20. Trypsin
 Trypsin is a protease found in the digestive
system of many vertebrates, where
it hydrolyses proteins.
 Trypsin is produced in the pancreas as the inactive
protease trypsinogen.
 Trypsin cleaves peptide chains mainly at
the carboxyl side of the amino
acids lysine or arginine
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21. Application of trypsin
 In a Animal tissue culture lab, trypsin is used to re-
suspend cells adherent to the cell culture dish wall
during the process of harvesting cells
 Used in proteomics experiments to digest proteins
into peptides for mass spectrometry analysis
 As a baking enzyme to improve the workability of
dough;
 in the extraction of seasonings and flavourings
from vegetable or animal proteins and in the
manufacture of sauces 21

22. Cont…
 To improve the texture of fish products
 To tenderize meat along with papain
 For cold stabilization of beer
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23. Cont…
 In the production of hypoallergenic food where
trypsin break down specific allergenic proteins into
non allergenic peptides
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