5 Fibrous Protein Function: That You Should Know

Fibrous proteins are mainly composition of many polypeptide chains which are elongated and fibrous in nature or sheet like structure. Due to arrangements of polypeptide chains in sheet manner, the fibrous proteins are mechanically strong and insoluble in water.

The structural component of fibrous proteins is mainly made up of primary and secondary structure, have very little tertiary structure. Fibrous proteins are also called as scleroproteins.

  • Structural component
  • Silk fibers of insects
  • Provide elasticity
  • Occupy space by mass
  • Suppot to nucleus
  • Blood clotting

Structural component

Keratin is the mainly the animal fibrous proteins which is present in various form in the animal body. Alpha-keratin are important structural component of the human skin. It is the integral part of hairs, nails, feathers, scales, beaks, claws and hooves.

Keratin provide muscular strength to the tissues such as tongue. Keratin participate in the cytoskeleton’s intermediate filament. Alpha-helices present in the alpha-keratin are interwinds to forms coils which further form disulphide bonds (cysteine) increasing structural strength.

Keratin protect the epithelial cells from external damage or stress. Due to excessive deposition of keratin protein, participate in the fortification of certain tissues like horns of rhino and cattle.

Silk fibers of insects

Fibroin is the insoluble fibrous protein that is part of silk of spiders, larvae of moths and other insets. . The tight packing character of fibroin protein in the spider silk is due to small R-group of glycine and alanine are present in the repeated manner.

Bombyx mori released the silk I type fibroin which is natural one from its silk glands. Silk II considered to the arrangement of fibroin protein in spun silk, having greater strength, due to this used commercially. Silk III the newly known fibroin protein which is formed at the interface places ( i.e. water-oil interface, air-water interface, etc.).

Provide elasticity

As the name indicates, the elastin protein is elastic in nature. The elastin protein provide elasticity to many tissues to allow them the regain its shapes after contracting or expanding. Elastin protein in the arteries helps with facilitating blood flow by pressure wave propagation.

Elastin is the major component of extracellular matrix of gnathostomes (jawed vertebrates). Elastin present in may type of connective tissues. It helps to regain the skin shape after poked or pinched.

It is also known for load-bearing protein as in the bodies of vertebrates and used where mechanical energy is required to be stored. The ELN gene is responsible for elastin protein in humans.

Occupy space by mass

In the mammals, the collagen protein occupying up to one third of the total mass. Collagen forms major composition of tendon connective tissue and also found in the skin. Collagen proteins are found in the cartilage, cornea, bones, gut and blood vessels.

Collagen chains is mainly composed of repeating units of glycinem-n where m is proline and n are hydroxyproline. Collagen is usually present as precursor form. As pro-collagen is exit from the cell and the protein cutting enzyme protease trim it, resulting in the active form collagen called tropocollagen.

Collagen protein play a major component of endomysium in the muscles. Collagen is widely used in the food industry as Gelatin . Collage is used in medical stream for the correction of complications of bones and skin.

Support to nucleus

Lamins proteins are the type of fibrous protein that provide structural support to the cell nucleus and play a major role to the transcription regulation. It helps to form Lamins of nuclear envelop, it plays a key role in the assembling and dissembling which will happen in the mitosis process in future.

Lamins are present in all kind of animals except prokaryotes, plants and fungi. Lamins are known to have elastic and mechanosensitive properties and can alter regulation of genes in the feedback response to mechanical cues.

Lamins plays an indirect role in anchoring the Endoplasmic reticulum from the nucleus, forming a continuous chain within the cell. Nucleus which do not have lamin or have defected lamin protein usually have a deformed nucleus shape and nucleus functioning is not properly.

Blood clotting

Fibrin also known as Factor Ia is the type of fibrous protein that help in blood clotting. It is formed by the action of enzyme protease thrombin on the precursor fibrinogen. The blood clot is mainly the polymerize fibrin protein with the platelets form a hemostatic plug or clot on a wound place.

Fibrous protein functions in cell membrane

Fibrous protein act as static and structural molecule which play an important role in the physiology and anatomy of vertebrates, provide external protection , shape , support and form.


To wrap up our article, we can state that fibrous protein play an important role in the structural formation of cells and tissues. Fibrous protein provide shape and support to the cell. fibrous protein also play a key role in blood clotting during injury.

Tanu Rapria

Hi..I am Tanu Rapria, I have completed my Master's in Biotechnology. I always like to explore new areas in the field of Biotechnology. Apart from this, I like to read, travel and photography.

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