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:
1. carrier ionophores
2. 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. Application
 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