Protein Engineering

1. LECTURE 8: Protein Engineering Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University of Sciences and Technology (NUST)

2. Protein Structure and Function • Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. • A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. • The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code.

3. Protein Engineering • The design and construction of new proteins or enzymes with novel or desired functions, through the modification of amino acid sequences using recombinant DNA technology. • The sizes and three dimensional conformations of protein molecules are also manipulated by protein engineering.

4. Protein Engineering • Proteins are engineered mainly for two reasons: • To elucidate the molecular basis of protein structure and function relationships and to understand catalytic mechanism. • To alter protein structure and function either rationally or randomly, i.e. protein design. • Most ambitious goal of protein engineering is designing a new function in proteins of known structure

5. What can be engineered in Proteins? Folding(Structure): • Thermodynamic Stability • Thermal and Environmental Stability (Temperature, pH, Solvent, Detergents, Salt …..)

6. What can be engineered in Proteins? Function: • Binding (Interaction of a protein with its surroundings) • How many points are required to bind a molecule with high affinity? • Catalysis (a different form of binding – binding the transition state of a chemical reaction)