Ionophores

the ionophores are the a part of membrane transport system. these slides include general concept of ionophores. useful for the paramedical, medical students.

1. IONOPHORES Bhupendra regmi Msc medical biochemistry Jssmc mysuru ionophore

2. INTRODUCTION Ionophores are compounds transporting small molecular compounds such as ions across the membranes. There are two types of ionophores : carrier ionophores channel forming ionophores . Examples are antibiotics such as valinomycin and gramicidin A ionophore

3. carrier ionophores Carrier ionophore increases the permeability for a particular ion. It binds to the ion and releases the ion on the other side of the membrane. Valinomycin is carrier ionophore . Valinomycin is selective for the transport of potassium. It binds to potassium and transports potassium across the membrane. Valinomycin inhibits the proton gradient across the mitochondrial membrane thus inhibiting oxidative phosphorylation. ionophore

4. ionophore FIGURE:carrier inophore ( valinomycin )

5. channel forming ionophores Channel forming ionophore forms a channel in the membrane by creating a space between two adjacent phospholipid molecules. Gramicidin A is a polypeptide,It is a channel forming ionophore . Gramicidin facilitates the passage of sodium and potassium ions across the membrane. It inhibits the proton gradient across the mitochondrial membrane thus inhibiting oxidative phosphorylation. ionophore

6. ionophore FIGURE: Channel forming ionophore (gramicidin)

7. Machanism of action:ionophore They are the chemical compounds that reversibly bind and transport  ions  through  the biological membrane  in the absence of a protein pore. This can alter the membrane potential and thus these substances could exhibit cytotoxic properties . Ionophores modify the permeability of biological membranes toward certain ions to which they show affinity and selectivity. ionophore

8. Many are lipid soluble in nature  and transport ions across hydrophobic membranes, such as lipid bilayers found in the living cells or synthetic vesicles (liposomes), or liquid polymeric membranes (carrier-based ion selective electrodes).  Structurally, an ionophore contains a hydrophilic center and a hydrophobic portion that interacts with the membrane. Ions are bound to the hydrophilic center and form an ionophore -ion complex. The structure of the ionophore -ion complex has been verified by X-ray crystallography. ionophore

9. A pplication Used in cell physiology and biotechnology experiments to alter the cell membrane gradient and ions across the membrane which enhanced the activity of the ion inside cell. Some ionophore shown antifungal and antibacterial activities. Chloroquine a type of ionophore used as a antimalarial drug. A large amount of research has been directed toward investigating novel antiviral, anti-inflammatory, anti-tumor, antioxidant and neuroprotective properties of different ionophores . ionophore

10. REFERENCE AROOR MEDICAL BIOCHEMISTRY U SATYANARAYANA BIOCHEMISTRY DM VASUDEVAN TEXT BOOK OF MEDICAL BIOCHEMISTRY ionophore

11. THANK YOU ionophore