University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

52

Pages:

5
Author:

Sheha A.

Quaternary Structure of Protein Protein having more than one polypeptide chain shows higher structure called. It referred to special arrangement of an oligomeric protein. Ex of Hemoglobin | Immunoglobulin | Lactate dehydrogenase. Bond Stabilizing Quaternary Structure Weak non-covalent hydrogen bonds, vander waals forces, ionic bonds & also few disulfide bonds. Quaternary structures are interactions b/w polypeptide chains. Importance of Quaternary Structure Higher structure of protein are mainly important for their biological activity. Denaturation of Proteins Process of disorganization of native protein structure is called denaturation. It involves the loss of secondary, tertiary, & quaternary structure without breaking the primary structure. Agents Causing Denaturation Physical Agent: Pressure, Heat, X-Rays/UV Radiation, Ultra Sound etc. Chemical Agent: Acids, Alkali, Organic Solvent (Ether, Alcohol etc), High Concentration of Urea, Heavy Metals etc. Isoelectric pH of Protein (pI) pH at which protein exists as zwitter ions (or dipolar ions) carrying equal numbers of +ve/-ve charge. So at pI net charge of protein is zero. So they will not move under an electric field. Importance of Quaternary Structure Higher structure of protein are mainly important for their biological activity. Isoelectric Precipitation of Protein Precipitation of protein at this isoelectric pH (pI) Ex of Denaturation of Protein High temperature Raw Egg White (Globular Protein) Boiling Hard Egg White (Fibrous Protein)