Difference Between Collagen and Elastin

Main Difference – Collagen vs Elastin

Collagen and elastin are two types of proteins that form the fibrous component of the connective tissue. Collagen is wide spread in the body than elastin. The main difference between collagen and elastin is that collagen gives strength and flexibility whereas elastin returns the stretched structures into the original shape. Collagen is a white color protein whereas elastin is a yellow color protein. Collagen is the third abundant protein in a mammal’s body. It is found in connective tissues as well as in skin, tendon, ligaments, and bones. Elastin is the major protein found in elastic connective tissues. It is mainly found in blood vessels and skin.

Key Areas Covered

1. What is Collagen
      – Definition, Characteristics, Function
2. What is Elastin
      – Definition, Characteristics, Function
3. What are the Similarities Between Collagen and Elastin
      – Outline of Common Features
4. What is the Difference Between Collagen and Elastin
      – Comparison of Key Differences

Key Terms: Collagen, Connective Tissue, Elastin, Extracellular Matrix, Fibroblasts, Fibrous Proteins, Tropocollagen, Tropoelastin, Type I Collagen

What is Collagen

Collagen is the main fibrous protein in the body. It is mainly found in the extracellular matrix of connective tissues. Collagen makes up the 25% of the total protein mass of a mammal. Collagen mainly comprises of amino acids, glycine and proline. It also consists of hydroxyproline and arginine. The collagen is stained in pink in H&E staining. Fibroblasts in the connective tissue secrete collagen as procollagen. Vitamin A, vitamin C, and copper are required for the production of collagen in fibroblasts. The cleavage of the end amino acids in procollagen forms the collagen, which ultimately aggregates into fibers. A collagen molecule is composed of three protein chains wrapped around each other, forming a helix. A large collagen aggregate is called a tropocollagen, which is formed by the aggregation of collagen fibrils. Collagen fibrils are cross-linked together in order to achieve a large tensile strength. Around 15 types of collagen are found. Type I collagen is the most abundant among them. The type I collagen can be found in skin, cornea, tendon, ligaments, and bone. The basal lamina of the skin is formed by type V and VI collagens. The type VI collagen anchors the basal lamina of the skin to the underlying connective tissue. Collagen fibers show a 64 nm banding pattern under the electron microscope. The formation of collagen fibers is shown in figure 1.

Figure 1: Formation of collagen fibers

The main function of collagen is to provide strength to the structures of the body. Collagen is also involved in protecting the body from pathogens, toxins, and cancerous cells since collagen hold the internal structures together. Collagen is also found in tendon, ligaments, and bones. It is found in blood vessels, smooth muscles, digestive tract, gallbladder, kidney, and heart as well.

Figure 2: Collagen fibers

The collagen production slows down with age, weakening the structures. This cause thinner and easier damaged skin, skin sags and wrinkles, and joints get stiff. An electron micrograph of collagen is shown in figure 2.

What is Elastin

Elastin is the major protein in the connective tissue found in elastic structures. It gives a snap back property to the structures when they are stretched. The production of elastin occurs in the early developmental stages and the childhood. The major protein component of the blood vessels is elastin. Therefore, the loss of elastin may cause atherosclerosis. The loss of elastin in lungs cause emphysema. The half-life of elastin is 70 years. The loss of elastin in the skin decreases the flexibility of the skin and reduces wound healing ability.

Figure 3: Elastin in younger and older skin

Fibroblasts produce tropoelastin, which becomes elastin in the extracellular matrix. Human elastin is capable of penetrating the skin and incorporating to the extracellular matrix. Elastin in both younger and older skin is shown in figure 3.

Similarities Between Collagen and Elastin

Both collagen and elastin are proteins which form the fibrous component of the connective tissue.
Both collagen and elastin are produced by fibroblasts.
Both collagen and elastic give strength and flexibility to body structures.
The decreased production of collagen and elastin in the body leads to the wrinkles and leathery skin.

Definition

Collagen: Collagen is a main structural protein found in skin and the connective tissue.

Elastin: Elastin is a major structural protein in the connective tissue of the elastic structures.

Abundance

Collagen: Collagen is the third abundant protein in the body.

Elastin: Elastin is less abundant than collagen.

Color

Collagen: Collagen is white color protein.

Elastin: Elastin is a yellow color protein.

Location

Collagen: Collagen is found in the connective tissue, skin, blood vessels, corneas, muscles, and bones.

Elastin: Elastin can be found in blood vessels and skin.

Role

Collagen: Collagen gives strength to the structures.

Elastin: Elastin makes the structures elastic.

Production

Collagen: Collagen is produced throughout the life until ageing begins.

Elastin: Elastin is mainly produced in the fetus. It is no longer produced after puberty.

Affected by

Collagen: Collagen is affected by sunlight, autoimmune disorders, high sugar consumption, and smoking.

Elastin: Elastin is affected by sunlight, changes in weight, dehydration, lack of sleep, stress, and smoking.

Diseases

Collagen: Deficiencies in collagen form osteogenesis imperfect, chondrodysplasias, and Ehlers-Danlos syndrome.

Elastin: Deficiencies in elastin form Marfan’s syndrome, atherosclerosis, and emphysema.

Conclusion

Collagen and elastin are two fibrous proteins in the connective tissues. Both collagen and elastin are secreted by fibroblasts. Collagen provides strength to the body structures whereas elastin provides a snapback property to the body structures. Therefore, the main difference between collagen and elastin is the function of each protein in the body.

Reference:

1. Mandal, Ananya. “What is Collagen?” News-Medical.net, 8 Sept. 2014, Available here. Accessed 18 Aug. 2017.
2.“What Is Elastin? – Definition & Explanation.” Study.com, Available here. Accessed 18 Aug. 2017.

Image Courtesy:

1. “Collagen biosynthesis (en)” By User Solitchka on fr.wikipedia. Translated by GKFXtalk. – Originally from fr.wikipedia; description page is (was) here31 mai 2005 à 17:24 Solitchka 701×459 (45 223 octets) (CC BY-SA 3.0) via Commons Wikimedia
2. “Fibers of Collagen Type I – TEM” By Louisa Howard – (Public Domain) via Commons Wikimedia
3. “Younger skin vs older skin” By Lieslecath – Own work (CC BY-SA 4.0) via Commons Wikimedia