Proteolytic EnzymesProteolytic Enzymes

Prof. Harshraj. S. ShindeK. K. Wagh College of Agril. Biotech, Nashik. India

Proteolytic EnzymesProteolytic 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

Polypeptides amino acids2

Endopeptidases

Exopeptidases

Cont …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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List of proteolytic List of proteolytic enzymesenzymesa. Papainb. Ficainc. Bromelaind. Pepsin e. Renninf. Cathepsing. Trypsin

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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

Application of papainApplication of papainMeat Tenderizer- Papain ( a

protease found in papaya) is used as meat tenderizer to soften meat for cooking

Cont…Cont…Papain can be used to dissociate

cells in the first step of cell culture preparations.

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FicainFicain

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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BromelainBromelainBromelain 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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Bromelain is present in all parts of the pineapple plant but the stem is the most common commercial source

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Applications of bromelain Applications of bromelain Along with papain, bromelain is one of the most

popular proteases to use for meat tenderizinguse for meat tenderizing

Cooked pineapple does not have a tenderizing effect, as the enzymes are heat-labile

Preparation of meat ballsPreparation of meat balls

Systemic enzyme therapy (combinations of proteolytic enzymes such as bromelain, trypsin and papain) has been used in the treatment of treatment of breast cancerbreast cancer

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PepsinPepsin Pepsin is an enzyme whose zymogen (pepsinogen) is

released by the chief cellschief 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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Cont…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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Applications of pepsin Applications of pepsin Pepsin is commonly used in the

preparation of F(ab')2 fragments from antibodies

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Cont…Cont…Powder of pepsin is often used as

a dietary supplement to aid digestion

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RenninRennin 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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Application of rennin Application of rennin It is widely used in the production

of cheese

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CathepsinCathepsinCathepsins 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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Cont….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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TrypsinTrypsinTrypsin 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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Application of trypsin 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

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Cont…Cont…To improve the texture of fish products

To tenderize meat along with papain

For cold stabilization of beer

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Cont…Cont… In the production of hypoallergenic food

where trypsin break down specific allergenic proteins into non allergenic peptides

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