Protein denaturation

An overview about protein denaturation and its various type

1. PROTEIN DENATURATION PREPARED AND PRESENTED BY: SAROJ SINGH MASTERS OF SCIENCE IN BIOTECHNOLOGY

2. PROTEIN DENATURATION INTRODUCTION DEFINITION EXAMPLE LEVELS OF PROTEIN DENATURATION TYPES WHAT IS PROTEIN RENATURATION CAUSES OF PROTEIN DENATURATION EFFECTS OF PROTEIN DENATURATION CONCLUSION REFERENCE

3. INTRODUCTION WHAT IS PROTEIN Protein is the most abundantly found macromolecule of our biological system which is made up of amino acid residues which are held together by the help of peptide bond. It participates in various systems in our body such as digestive system, reproductive system etc. WHAT IS DENATURATION Denaturation is the process in which the folding structure of any molecule is altered due to the exposure of external stress which may be physical or chemical.

4. DEFINITION The process of partial and total alteration in native, secondary, tertiary and quaternary structure of protein due to exposure of certain chemicals and physical factors is called protein denaturation. Denaturation leads break down of various bond exist within a molecule and macromolecule. If protein in a living cell denatured results disruption of cell activity and possibly cell death.

5. EXAMPLE A classic example of protein denaturation is egg albumen which get hard and solid due to its denaturation on high temperature and convert into white color from its color less appearance.

6. HOW TO PROTEIN GET DENATURED If a solution containing protein is heated and treated with some chemical and physical factors resulting break down of the various bonds present in secondary, tertiary, quaternary structure of protein hence protein gets denatured and convert into its primary configuration.

7. LEVELS OF PROTEIN DENATURATION In quaternary structure of protein, during protein denaturation subunits of proteins are dissociated from each other and get separate. In tertiary structure of protein, during protein denaturation following changes our occurs: Disruption of covalent bond. D isruption of non covalent dipole-dipole bond. Disruption of Vander Val bonds.

8. In secondary structure of protein, during protein denaturation protein loss all repeating pattern such as alpha helix, beta pleated sheets etc . In primary structure of protein no changes occur during denaturation

9. TYPES OF PROTEIN DENATURATION 1). Irreversible denaturation Some protein after denaturation cannot brought be back to their native configuration, In that case denaturation is described as irreversible denaturation. 2). Reversible denaturation On the other hand when protein after denaturation is able to brought back on its native configuration, in that case denaturation is described as reversible denaturation.

10. TYPES OF PROTEIN DENATURATION

11. PROTEIN RENATURATION The process of regaining its normal properties by denatured protein is called protein renaturation. I ts occur when situations are getting normal which are hardly responsible for protein denaturation but the property of protein denaturation is only shown by few proteins all the proteins are not able to convert in its native configuration after denaturation of protein this type of denaturation is called reversible denaturation .

12. CAUSES OF PROTEIN DENATURATION Denaturation may be brought about by a variety of agents such as CHEMICAL FACTORS PHYSICAL FACTORS

13. CHEMICAL FACTORS OF PROTEIN DENATURATION 1). Salt concentration: Ammonium sulphate 2). Heavy metals: Hg ++ , Ag ++ ,etc. 3). Organic solvent: Acetone, alcohol. 4). Detergents: Sodium dodecyl sulphate.

14. PHYSICAL FACTORS OF PROTEIN DENTURATION 1). M echanical action : Shaking, rubbing. 2). TEMPRATURE: More than 41°C . Frozen temperature. 3). Hydrostatic pressure: 5000-10,000 atm. 4) Exposure of rays: X-Rays, UV-Rays

15. 5). pH: Change in pH can change the chemistry of amino acid residues and can lead the denaturation . 6 ). Oxidation : Oxidation of protein can destroy the stability of protein. 7 ). E nzymatic degradation : Protease is an enzyme which is specific to cleave protein and thus stability of protein will be lost.

16. EFFECTS OF PROTEIN DENATURATION Possibility to loss biological activity of protein. Decrease in size and shape. Change in its physical appearance. Disruption in its native structure. Disruption in cell activity. Production of toxins by denatured protein.

17. conclusion The process of unfolding of protein is referred as denaturation thus causing disorganization of the internal structure of protein which is capable to block cell activity and possibly leads cell death. The process of denaturation may be reversible or irreversible it is based upon the nature of amino acid residues which participates in its structure. It is caused by some external stress such as physical and chemical factor which include heat, exposure of UV-rays, X-rays and certain chemicals.

18. REFERENCES J. L. JAIN- FUNDAMENTALS OF BIOCHEMISTRY. ALBERT L. LEHNINGER-BOOK OF BIOCHEMISTRY. WWW.WIKIPEDIA.COM OTHER ONLINE SOURCES

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