Neurotransmitters: Difference between revisions
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*[[Huperzine A Complexed with Acetylcholinesterase]] & [[Huperzine A Complexed with Acetylcholinesterase (Chinese)]]<br /> | *[[Huperzine A Complexed with Acetylcholinesterase]] & [[Huperzine A Complexed with Acetylcholinesterase (Chinese)]]<br /> | ||
*Acetylcholinesterase complexed with [[Tacrine]], the 1st anti Alzheimer's drug<br/> | *Acetylcholinesterase complexed with [[Tacrine]], the 1st anti Alzheimer's drug<br/> | ||
*[[UMass Chem 423 Student Projects 2011-1#Acetylcholinesterase bound by Tacrine]] | |||
*[[Torpedo Californica Acetylcholinesterase in complex with an (R)-Tacrine-(10)-Hupyridone inhibitor]]<br /> | *[[Torpedo Californica Acetylcholinesterase in complex with an (R)-Tacrine-(10)-Hupyridone inhibitor]]<br /> | ||
*[[Torpedo Californica Acetylcholinesterase in complex with an (S)-Tacrine-(10)-Hupyridone inhibitor]]<br /> | *[[Torpedo Californica Acetylcholinesterase in complex with an (S)-Tacrine-(10)-Hupyridone inhibitor]]<br /> | ||
Revision as of 09:10, 16 December 2019
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Contents
AcetylcholineAcetylcholinesterase (EC 3.1.1.7, e.g. from Torpedo californica, TcAChE) hydrolysizes the neurotransmitter acetylcholine (ACh), producing choline and an acetate group. ACh directly binds Ser200 (via its nucleophilic Oγ atom) within the catalytic triad catalytic triad (Ser200, His440, and Glu327) of (ACh/TcAChE structure 2ace). The residues Trp84 and Phe330 are also important in the ligand recognition. After this binding acetylcholinesterase hydrolysizes ACh. Acetylcholine ReceptorsNicotinic Acetylcholine ReceptorsNicotinic Acetylcholine Receptors in general
Binding site of AChRAcetylcholine Receptor and its Reaction to Cobra VenomAcetylcholinesterase
Alzheimer's DiseaseAdrenaline (Epinephrine)/Noradrenaline (Norepinephrine)
Adrenergic receptors in generalThe adrenergic receptors are metabolic G protein-coupled receptors. They are the targets of catecholamines. The binding of an agonist to them causes a sympathetic response.
Beta-adrenergic receptorsBeta-1 Adrenergic receptorArticle Beta-2 Adrenergic Receptor by Wayne Decatur, David Canner, Dotan Shaniv, Joel L. Sussman, Michal HarelArticle Beta-2 adrenergic receptor by Joel L. Sussman, Tala Curry, Michal Harel, Jaime PriluskyGroup:SMART:A Physical Model of the beta-Adrenergic Receptor3D Structures of Adrenergic receptorsBeta-adrenergic receptor kinaseMonoamine oxidases (MAO)Monoamine oxidases (MAO) (EC 1.4.3.4) are a family of enzymes that catalyze the oxidation of monoamines including adrenaline, noradrenaline, serotonin and dopamine. Monoamine oxidaseMonoamine oxidase bDopamineDOPA decarboxylaseDopamine ReceptorsDopamine receptors are a class of metabotropic G protein-coupled receptors that are important in the central nervous system. Dopamine receptors are involved in many neurological processes that comprise motivation, pleasure, cognition, memory, learning, and fine motor skills. There are five subtype dopamine receptors, D1, D2, D3, D4, and D5. The D3 receptor is a part of the D2-like family.[3] AgonistsAntagonistsStructure of the human dopamine D3 receptor in complex with the antagonist eticlopride and maltose (3pbl). Parkinson's diseaseDOPA decarboxylase is responsible for the synthesis of dopamine and serotonin from L-DOPA and L-5-hydroxytryptophan, respectively. It is highly stereospecific, yet relatively nonspecific in terms of substrate, making it a somewhat uninteresting enzyme to study. Although it is not typically a rate-determining step of dopamine synthesis, the decarboxylation of L-DOPA to dopamine by DDC is the controlling step for individuals with Parkinson's disease[8], the second most common neurodegenerative disorder, occuring in 1% of the population over the age of 65. The loss of dopaminergic neurons is the main cause of cognitive impairment and tremors observed in patients with the disease. The hallmark of the disease is the formation of alpha-synuclein containing Lewy bodies. Currently, treatment for the disease is aimed at DOPA decarboxylase inhibition. Since dopamine cannot cross the blood-brain barrier, it cannot be used to directly treat Parkinson's disease. Thus, exogenously administered L-DOPA is the primary treatment for patients suffering from this neurodegenerative disease. Unfortunately, DOPA decarboxylase rapidly converts L-DOPA to dopamine in the blood stream, with only a small percentage reaching the brain. By inhibiting the enzyme, greater amounts of exogenously administered L-DOPA can reach the brain, where it can then be converted to dopamine. [9]. Unfortunately, with continued L-Dopa treatment, up to 80% of patients experience 'wearing-off' symptoms, dyskinesias and other motor complications (referred to as the "on-off phenomenon". [10]. Clearly, a better understanding of the catalytic mechanism and enzymatic activity of DDC in both healthy and PD individuals is critical to drug design and treatment of the disease. GlutamateGlutamate receptorsIonotropic Glutamate ReceptorsIonotropic Glutamate Receptors (IGluRs) are a family of ligand-gated ion channels that are responsible for fast excitatory neurotransmission.[11] Primarily localized to nerve synapses in mammals, IGluRs are implicated in nearly all aspects of nervous system development and function.[12] Synapses form the connection between two neuronal cells. Within synapses, neurotransmitters are released from vesicles in presynaptic cells and interact with receptors in postsynaptic cells to allow for communication between nerve cells.[11] GluR domains include the amino terminal domain (ATD), transmembrane domain (TMD) and ligand-binding domain (LBD). Glutamate is the predominant neurotransmitter of excitatory synapses and interacts specifically with AMPA and NMDA IGluRs.
Metabotropic Glutamate ReceptorsMetabotropic glutamate receptors are glutamate receptors that activate ion channels indirectly through a signaling cascade involving G proteins[13]. They are members of the large class of seven-transmembrane domain receptors, the G protein-coupled receptors. Glutamate receptors are classified into 3 groups based on their homology, mechanism and pharmacological properties.
AMPA receptorsHistamineHistamine receptorsAllergy symptoms are mostly caused by the release of histamine in response to allergens. The binding of histamine to the extracellular portion of the H1 receptor triggers a structural change of the transmembrane portion, leading to a change in the C terminal area. This c terminal region interacts with G proteins, leading to the activation of the Gq signalling pathway, which triggers allergy symptoms like itchy eyes and runny noses. Many allergy drugs are anti-histamines, in that they bind to the histamine receptor but do not cause the conformational change that leads to a response. Histamine H1 receptor NeurotensinNeurotensin receptorsThe neurotensin receptor (NTSR1) belongs to the superfamily of proteins known as G protein-coupled receptors (GPCRs). Currently around 800 G protein-coupled receptors have been identified and are hypothesized to be responsible for roughly 80% of signal transduction.[14] GPCRs are involved in a vast array of physiological processes within the body that range from interactions with dopamine to effects on secretion of bile in the intestines.[15] [16] Due to the vast array of functions that these proteins serve and their high abundance within the body, these proteins have become major drug targets.[17] The ligand for NTSR1 is the 13 amino acid peptide, neurotensin (NTS)[18], and the majority of the effects of NTS are mediated through NTSR1[18]. NTS has a variety of biological activities including a role in the leptin signaling pathways [19], tumor growth [20], and dopamine regulation [21]. NTSR1 was crystallized bound with a C-terminal portion of its tridecapeptide ligand, NTS(8-13). The shortened ligand was used because of oits higher potency and efficacy than its full-length counterpart[18]. SerotoninSerotonin receptors5-hydroxytryptamine (5-HT), Serotonin receptors are found on the membrane of neurons in the central nervous system and peripheral nervous system. These receptors allow for the body to respond to serotonin and regulate many biological pathways. Serotonin, also known as 5 hydroxytryptamine, is an endogenous neurotransmitter made from tryptophan and is largely found in the gastrointestinal tract. It is known to regulate mood, appetite, digestion, circadian rhythm, learning and internal temperature regulation. It is can be an inhibitory or excitatory neurotransmitter that is released into the synaptic space and can bind to receptors on the postsynaptic neuron or be taken back up into the presynaptic neuron via Serotonin re-uptake transporters.[22] 5-HT receptors are classified into 7 different subfamilies (5-HT1, 5-HT2, 5-HT3, etc.) by signaling mechanisms and homology of structure. All 5-HT receptors are known to have G-protein linked pathways except for the 5-HT3 receptor which acts as an ion channel. [23] Serotonin receptors, main page3D structures of Serotonin receptors5-HT3A receptorSerotonin TransporterSee also Serotonin N-acetyltransferase
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References
Proteopedia Page Contributors and Editors (what is this?)
- Topic Page
- Acetylcholine
- Receptor
- Nicotinic
- Acetylcholine Receptor
- Acetylcholinesterase
- Alzheimer's disease
- Inhibitor
- Adrenaline
- Epinephrine
- Norepinephrine
- Adrenergic
- Adrenergic Receptors
- Monoamine oxidase
- Dopamine
- Parkinson's disease
- Serotonin
- G protein-coupled receptor
- G-protein coupled receptor
- G-protein-coupled receptor
- Gpcr
- Membrane protein
- Histamine