Molecular Basis of Drugs Action

Drug Design and Molecular Pharmacology: 

Presented by: Kireety Dinakar J M Pharm 1 st year Drug Design and Molecular Pharmacology Smt. Sarojini Ramulamma College of Pharmacy Mahabubnagar , Andhra Pradesh, India 01

Molecular Basis of Drug Action: 

Molecular Basis of Drug Action Contents : Cell Signaling Cell communication Ion Channels Signal Transduction Pathways Third messengers Biosensors 02

Cell Signaling:: 

Cell Signaling: Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions . Used to the development , tissue repair, and immunity as well as normal tissue homeostasis . Errors causes cancer , autoimmunity, and diabetes. 03

Cell communication : 

Cell communication Multi cellular organisms possess cells to compartmentalize various chemical reactions in order to use available materials for energy and maintenance of life. In order to coordinate their activities the different cells in multi cellular organisms need to communicate with each other . 04

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Cell communication No distance Cell-1 Cel-2 APC S hort distance Long distance Cell-1 Cell-1 Cell-1 Cell-1 Neurotransmitters Hormone 05

Cell communication: 

Cell communication 06

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Ag macrophage Helper T cell B cell Killer T cell 07

Signal transduction: 

Signal transduction Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response . There are two stages in this process: A signaling molecule activates a specific receptor on the cell membrane. A second messenger transmits the signal into the cell, eliciting a physiological response . 08

s.t. pathways: 

s.t. pathways Type 1: Direct Ligand-gated Channel type. Ex: nicotinic acetylcholine receptor, GABA receptor. Type 2: G-protein-coupled type. Ex: Muscarinic acetylcholine receptor, Adrenergic receptors. Type 3: Tyrosine-kinase-linked type . Type 4: Intracellular Steroid/Thyroid type. 09

Type 1: GABA Receptor: 

Type 1: GABA Receptor 10

Type 2: G-Protein Coupled receptor: 

Type 2: G-Protein Coupled receptor 11

Type 3: Tyrosine-kinase-linked type: 

Type 3: Tyrosine-kinase-linked type Phosphorylation = cell differentiation, metabolism 12

Type 4: Intracellular Steroid/Thyroid type: 

Type 4: Intracellular Steroid/Thyroid type 13

Ion Channels:: 

Ion Channels: Passive/Leakage Ion-channels. Na+/K+ Pump. Voltage Gated Ion-channels. Ligand Gated Ion-channels . 14

PowerPoint Presentation: 

Passive/Leakage Ion-channels Allow ions to passively cross the membrane. Ion selective. More channels Increased conductance/ Decrease resistance. Located throughout the neuron. Sodium/Potassium Pump Na+/K+ Pump. Pumps 3Na+ out and 2 K+ ions in. Takes energy from ATP. Located all throughout the neuron. 15

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Voltage Gated Ion-channels Open in response to changes in membrane voltage( E m ). Main classes: Na+ and K+. Found I the Axons and Axon terminals (Ca 2+ ). Ligand Gated Ion-channels Opens when it binds to specific molecules(Ligands). Found in the input region of neuron (Dendrites and Soma). 16

Third messengers:: 

Third messengers: Recent research has begun to clarify the complex molecular links between the secondary messenger and its ultimate effect upon cellular functions . These links are specifically third, fourth and subsequent chemical messengers in the signal transduction cascades . Each of these four classes of signal transduction cascades are not only begun with a different first messenger binding to a unique receptor but also leads to activation on very different stream second, third ad subsequent chemical messengers. Having many different signal transduction cascades allows neurons to respond in amazingly diverse biological ways to whole array of chemic messaging systems. 17

Biosensors:: 

Biosensors: A biosensor is an analytical device for the detection of an analyte that combines a biological component with a physicochemical detector component. It consists of: 1) The sensitive biological element 2) The transducer or the detector element 3) Biosensor reader device 18

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Regards: Kireety dinakar J dinakarkireety@gmail.com