Protein folding

how protein folding occur. location of protein folding

1. Protein folding Presented by: saba naeem 2015-mphil-2368 Uvas lahore

2. What is protein Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body's tissues and organs

3. Types of protein Proteins are broadly classified into two major types depending upon there structure and function Globular protein Fibrous protein

4. Globular protein Compact form Water soluble (hydrophilic side chains) Important role in enzymatic and molecular action Hemoglobin , myoglobin, insulin

5. Fibrous protein Long protein filament Water insoluble (hydrophobic side chains) Important role paly in Stability Collagen, elastin

6. Structure of protein Proteins are actually amino acid chain, these are also known as polypeptide chains, formed in the result of translation Primary structure Secondary structure Tertiary structure Quaternary structure

7. Primary structure protein Consist of amino acid sequence Stability factor: Peptide bond Terminal electrostatic interaction Cis /trans structure (trans isomerase )

8. Secondary structure protein Alpha helix Single stranded, Right handed coiled, spiral with 3.6 amino acid per spiral turn Beta pleated sheet Double stranded, can be parallel or anti parallel Beta bends Join two beta sheets or/and alpha helix with each other

9. Cont’d Super secondary motifs These consist number of alpha helix & beta sheets with in the same strand Stability factors Peptide bond Terminal electrostatic interaction H-BONDING

10. Tertiary structure protein protein's geometric shape. The tertiary structure will have a single polypeptide chain "backbone" with one or more protein secondary structures STABILITY FACTORS Peptide bond Terminal electrostatic interaction H-BONDING Hydrophobic interaction Disulphide bond

11. Quaternary structure protein A rrangement of multiple folded protein or coiling protein molecules in a multi-subunit complex Stability factors H-BONDING Ionic bond/ salt bridge

12. Protein Folding

13. Chaperone these are protein molecules Function: Help in protein folding Prevent aggregation Example: GroEL is bacterial chaperone Heat shock proteins in eukaryotes

14. Models of protein folding Diffusion collision model Nucleation –condensation model

15. MISFOLDING OF PROTEIN Following factors will lead to mis -folding of proteins absence of normal supporting/co factors absence of chaperone protein Change in temp Change in pH

16. FATE OF normal PROTEIN MOLECULE After there formation by ribosome and along side folding in RER, they under go post translational modifications in ER, Golgi and cytoplasm The cytoplasmic proteins act as enzyme and help in metabolic process While surface proteins move toward the cell surface where they act as receptor molecule/ gated channels/ pump proteins Extracellular protein moves out side by exocytosis and act as circulating molecule/ hormones etc

17. Fate of abnormal protein In normal case abnormal/ mis folded proteins are degraded by Ubiquitin proteasome pathway Mis folded proteins act as non function or malfunction proteins which may result in disease process Example; Amyloid protein result in Alzheimer disease

18. Thank you