PROTEASEBY : MOHAN NAIK . G

M.Tech (Food Processing Technology)

College of FPT & BE,

AAU, Anand.

Proteases are abundantly and widely distributed in biological world including plant, animal and microbes .

Protease is group of enzyme that performs proteolysis known as hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein .

Proteases constitute more than 70% of industrial enzyme alone and microbial sources (bacterial and fungal) are leading supplier of these enzyme.

Introduction

These enzymes possess catalytic activity in broad range of temperature and pH (temperature ranges 5 -100 °C and in pH range 0-14 ).

Protease widely used as detergent, in food, pharmaceutical and leather tanning industries.

The vast variety of proteases, with their specificity of their action and application has attracted worldwide attention to exploit their physiological as well as biotechnological application.

The specificity of protease binding is not defined solely by the nature of the catalytic centre. On either side of the catalytic centre there is a series of binding sites (S) that favour particular amino acids (P).

MECHANISM OF ACTION OF PROTEASES

By source organism:

1. Animal : chymosin, trypsin, pepsin 2. Plant : bromelain, papain, ficin 3. Bacterial: subtilisin(Bacillus subtilis), bacillopeptidases 4. Fungal : Aspergillopepsin

By proteolytic mechanism:

a. Serine proteases b. Threonine proteases c. Cysteine proteases d. Aspartic proteasese. Metallo proteases f. Glutamic acid proteases

Classification of Protease

By active pH range:

1. Acid proteases2. Neutral proteases 3. Alkaline proteases 4. High-alkaline proteases

Microbial protease

Major fungi producing alkaline proteases

Aspergillus candidus , A. flavus , A. fumigatus , A. melleus , A. niger , A. oryzae , A. soja, Cephalosporium sp.

Major bacteria producing alkaline proteases

Streptomyces microflavus , Streptomyces moderatus , Streptomyces rectus, Pseudomonas aeruginosa , Pseudomonas maltophilia , Pseudomonas sp. SJ320

The serine proteases contribute major industrial and therapeutic protease where serine serves as the nucleophilic amino acid.

In this class of enzyme chymotrypsin/trypsin and subtilisin are commercially available serine protease .

With their tremendous scope in industry and medicine several recombinant serine protease have been produced and are in commercial use.

Serine proteases (EC 3.24.21)

Threonine protease is another industrially significant protease where threonine (Thr) residue lies on catalytic site.

These proteases have much significance in physiology and proteasome and acyl transferases are classical example

Threonine proteases (EC 3.4.25)

Cysteine proteases also known as thiol protease possess great importance in industrial applications.

These proteases perform catalysis associated with nucleophilic thiol in a catalytic triad or dyad.

These proteases are primarily present in all the fruits including papaya, pineapple, fig and kiwi fruit.

Cysteine proteases had shown their potential in poultry industry and are key competent of meat tenderizers.

Cysteine proteases (EC 3.4.22)

Aspartic acid proteases are quite different from other proteases as their contribution in maintaining physiological functions.

The classical examples are pepsins, cathepsins, and renins key enzyme which maintain physiology .

Glutamic acid proteases (EC 3.4.19) Most important glutamic acid proteases which are widely

present in fungal species are key enzyme for food processing and modern therapeutics such as antitumor and anticancer .

Aspartate proteases (EC 3.4.23)

A novel protease group called metalloprotease which enormously used in drug development involve metal ion for catalysis.

Due to wide range of substrate affinity and diverse sources of proteases the applications of proteases are unique and widely applicable in different industries .

Metallo-proteases (MMPs) (EC 3.4.24)

Commercial production

Used on a large commercial scale in the production of bread, baked goods, crackers and waffles . To reduce mixing time, To decrease dough consistency, To assure dough uniformity, To regulate gluten strength in bread, To control bread texture and to improve flavour .

Endo and exo-proteinases from Aspergillus oryzae have been used to modify wheat gluten by limited proteolysis

Application in bakery industry

The major application of proteases in the dairy industry is in the manufacture of cheese. The milk-coagulating enzymes fall into three main categories, (i) animal rennets, (ii) microbial milk coagulants, and (iii) genetically engineered chymosin.

In cheese making, the primary function of proteases is to hydrolyze the specific peptide bond to generate para-κ-casein and macro peptides.

Application in dairy industry

Chymosin is preferred due to its high specificity for casein, which is responsible for its excellent performance in cheese making.

The microbial enzymes exhibited two major drawbacks, i.e., (i) the presence of high levels of nonspecific and heat-

stable proteases, which led to the development of bitterness in cheese after storage; and

(ii) a poor yield.

Proteases have been used from ancient times to prepare soy sauce and other soy products.

The alkaline and neutral proteases of fungal origin play an important role in the processing of soy sauce.

Proteolytic modification of soy proteins helps to improve their functional properties.

The hydrolysate is used in protein-fortified soft drinks and in the formulation of dietetic feeds.

Manufacture of soy products

The medicinal application of protease for diagnostic and therapeutic is widely accepted and several enzymes are in use since many years.

anti- cancer, anti-inflammatory, antimicrobial and clot dissolving agents

Therapeutic application of proteases

The most common types of enzymatic tenderizers are 

Bromelain, which is made from pineapples.

 Papain, which is made from papayas

Actinidin, which is made from kiwis

Ficin, which is made from figs.

Meat industry

Proteases of Aspergillus find application as digestive aids in gastro-intestinal disorders such as dyspepsia.

Papain and bromelain have been used to improve the nutritional value of feeds. Papain has been used to manufacture yeast extract and SCP.

It has also been used in the extraction of flavour and colour compounds from plants.

Other application

Other applications, which exploit the hydrolytic property of proteases, include soy protein hydrolysis, soy sauce production, gelatine hydrolysis, casein and whey protein hydrolysis, meat protein recovery, fish protein hydrolysis, and meat tenderization.

Proteases from Bacillus subtilis have been used to deproteinize crustacean waste to produce chitin.

Neutrase is a bacterial protease which is used in alcohol production for improving yeast growth In brewing.

Medicine Pharmacology & drug manufacture Laundry & dishwashing detergents Hard surface cleaning formulations Contact lens cleaning formulations Waste treatment Industrial applications Fermentation (fuel EtOH, etc.) Chondroitin & heparin production

Non food application

J. Srilakshmi, ;J. Madhavi, Lavanya S and Ammani (2014)Commercial Potential of Fungal Protease: Past, Present and Future Prospects , Journal of Pharmaceutical, Chemical and Biological Sciences ,2(4)p.218-234.

Sumantha (2006).Food-Grade Proteases, journal of Food Technology & Biotechnology. 44 (2), p.211–220

Riddhi Sawant and Saraswathy Nagendran (2014),protease: an enzyme with multiple industrial application, www.wjpps.com .

Reference