Classification of protein

CLASSIFICATION OF PROTEIN

1) CLASSIFICATION  BASED ON THEIR FUNCTIONS

2)CLASSIFIED ON THE BASIS OF THEIR PROPERTIES

1) CLASSIFICATION ON THE BASIS OF THEIR FUNCTIONS

1catalytic proteins  (enzymes)

2structural proteins

3Contractile protein

4Transport protein

5Regulatory protein or harmonal protein

6Genetic protein

7Immunoproteins

1 catalytic  protein

1)Oxidoreductase oxidation combination of oxygen and loss of electron and loss of hydrogen 

Reduction  

Removal  of oxygen and gain of electron gain of hydrogen 

2) Transferases

3)Hydrolase

4)Lyase 

5)Isomerase 

6)ligase

2 STRUCTURAL PROTEINS

Collagen ( found in liver and heart)  elastin ( found in joints) lipoproteins ( cell membrane)  keratins ( hair nails and horns)

 

3 CONTRACTILE PROTEIN   

 

Actin , Myosin ,Flagellar proteins.

 

4 TRANSPORT OF PROTEIN

1Haemoglobin 2 Myoglobin 3Haemocyanin 4serum proteins  Myoglobin and plasma proteins albumin and globulin .

5 REGULATORY PROTEINS

1ACTH Adrenovortrophic harmone

Peptide harmone(insulin and glucagon)

MSH Melanin synthesize harmone .

6 GENETIC PROTEINS

Nucleoprotein and histones

  

7 IMMUNOPROTEINS

Gamma globulins alpha globulin beta globulin represents antibody and say to be as immunoglobulins.

2 CLASSIFIED ON THE BASIS OF PROPERTIES

1 SIMPLE PROTEINS

2CONJUGATE  PROTEINS 

3DERIVED PROTEINS

1SIMPLE PROTEINS 

These proteins yield only only amino acids upon completely hydrolysis . 

Examples 1 Albumins 2Globulins 3Glutelins 4Prolamines 5Albuminoids or scleroproteins  6 Histones 7 protamines

1 ALBUMINS 

The protein when islolate by first latin word albus means white are widely distributed in plants and animals .The albumins are soluble in water examples egg albumin serum albumin and lactalbumin  it is a good quality protein and it is maximum biological value .

2 GLOBULINS  

 This protein when isolated and examine found as a round ball or drop of water behind the shape of protein named as globulins. The globulins are insoluble in water but they are soluble in dilite natural salts of alkalies and acids are heat coagulable .

3 GLUTELINS   

Soluble in dilute acids and alkalies and mostly found in plants 

Examples glutelin ( wheat) and oryzenin ( rice)

4 PROLAMINES

Soluble in 70% alcohol  e.g gliadin ( wheat) ,zein(rice) .

5 HISTONES

 Strongly basic proteins , soluble in water dilute acids but insoluble in dilute ammonium hydroxide.

6 PROTAMINES

 SOluble in 70% alcohol e.g gliadin(wheat) Zein(maize) .

B) FIBROUS PROTEIN 

 THese are fiber like in shape insoluble in water and resistant to digestion .ALBUMINOUDS AND SCLEROPROTEIN  are predominant group of fibrous protein.

1 collagen 

 Are connective tissues protein 

2 ELASTINS

These proteins are found in elastic tissues such as tendons and arteries.

3 KERATINS

These are present in exoskeletal  structures e.g hair , nails ,horns .

2 CONGUGATE PROTEINS 

The conjugate proteins are those  proteins in which simple proteins are combined with some non protein substances  . The non protein group is reffered to as prosthetic group additional group is known as conjugate proteins   

Examples 1 Nucleoproteins  2 Glycoproteins 3 lipoproteins  4 Phosphoproteins  5 Chromoproteins  7 Metalloproteins . 

 1 NUCLEOPROTEIN

  Nucleic acid (DNA) or(RNA)  is the prosthetic group e .g nucleohistones ,nucleoprotamines. 

 

2 GLYCOPROTEINS

The prosthetic group is  carbohydrates which is less than 4% of protein. The term MUCOPROTEIN  is used  if the carbohydrate content is more than 4% e.g mucin ( saliva), ovomucoid (egg white).

3 LIPOPROTEIN

Protein found with combination with lipids as the prosthetic group  e.g serum lipoproteins.

4 PHOSHOPROTEIN  

Phosphoric acid is the prosthetic group e.g casein (milk)  vitelline (egg yolk).

 

5 CHROMOPROTEIN

The prosthetic group is coloured in nature  e.g hemoglobins ,cytocromes .

6 METALLOPROTEINS 

These proteins contains metal ions such as Fe, Co ,Zn, Cu ,Mg, etc 

3 DERIVED PROTEINS 

THese proteins which can  be derived or formed from simple or conjugate  proteins is called derived proteins . 

There are two types of derived proteins 

1 PRIMARY  DERIVED PROTEINS  

Slightly changes  in the protein with  negligible hydrolysis  

There are three types of primary derived proteins  1 proteans 2 meta proteins and coagulated proteins

1 PROTEANS 

 THese are the earliest products  of protein  hydrolysis  by enzymes   , dilute acids , alkalies etc  which are insoluble in water  e.g fibrin formed from fibrinogen 

When myosin treated very dilute acids there  will be change in myosan properties resultant  protein unsoluble in salts of acids and alkalies  change in protein. 

  

2 METAPROTEINS 

THese proteins are obtained when protein solution treated with  acid and base  solution change in properties   If protein obtain from acid say to be as acid meta protein .If protein obtain from base say to be as base metaprotein .

E.g 1 acid metaprotein and 2 base meta protein 

3 COAGULATED PROTEANS 

The coagulated protein are insoluble products  formed by the action of heat or alcohol upon natural protein  these are the denatured proteins 

 e.g 1 cooked proteins coagulate albumin .

2 SECONDARY DERIVED PROTEIN

THe substances are formed  in the progressive hydrolytic cleavage  of the pepride bonds  of protein molecule . 

Three groups of  secondary protein

1 PROTEOSIS 

Or albumoses when any simple protein undergo  very little hydrolysis  is allowed  10 %  to form proteoses .

2 PEPTONES

peptones are hydrolytic products of simpler structure then the proteoses  .They are solubke in water and not coagulated by heat . Hydrolysis is allowed 30 % .

3 PEPTIDES 

Are composed of only a relatively few amino acids united through peptide bonds .They are named as according to the nmber of amino acids  dipeptides , tripeptides and tetrapeptides etc they are water soluble and not coagulated by heat .hydrolysis is alllowed 70 % .