Acetylcholinesterase: Difference between revisions
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THIS PAGE IS **UNDER CONSTRUCTION**, PLEASE BE PATIENT UNTIL IT IS COMPLETED! | THIS PAGE IS **UNDER CONSTRUCTION**, PLEASE BE PATIENT UNTIL IT IS COMPLETED! | ||
The increasing longevity of people's lifespans, and the resulting increased | The increasing longevity of people's lifespans, and the resulting increased | ||
prevelance of dementias such as Alzheimers Syndrome, led scientists to study the | prevelance of dementias such as Alzheimers Syndrome, led scientists to study the | ||
animal enzyme ''AcetylCholinEsterase'' ('''AChE''') as a possible culprit. This enzyme rapidly degrades the neurotransmitter acetylcholine in synapses (junctions between nerve cells) of cholinergic nerve pathways into acetic acid and choline, to turn off the chemical signal for the nerve to fire. Should something happen to deactivate or kill this vital enzyme, nervous paralysis of vital functions occurs, leading to rapid death. Although AChE is apparently not the cause of Alzheimers, it does seem to play a minor role, in that weak inibitory drugs such as Tacrine, E2020 (Aricept) and the natural Chinese natural produce Huperzine appear to delay symptoms. Furthermore, this enzyme is a key target of some very important nerve gasses and related insecticides. Furthermore, it is a pretty fascinating enzyme to study. | animal enzyme ''AcetylCholinEsterase'' ('''AChE''') as a possible culprit. This enzyme rapidly degrades or hydrolizes the neurotransmitter acetylcholine in synapses (junctions between nerve cells) of cholinergic nerve pathways into acetic acid and choline, to turn off the chemical signal for the nerve to fire. Should something happen to deactivate or kill this vital enzyme, nervous paralysis of vital functions occurs, leading to rapid death. Although AChE is apparently not the cause of Alzheimers, it does seem to play a minor role, in that weak inibitory drugs such as Tacrine, E2020 (Aricept) and the natural Chinese natural produce Huperzine appear to delay symptoms. Furthermore, this enzyme is a key target of some very important nerve gasses and related insecticides. Furthermore, it is a pretty fascinating enzyme to study. | ||
Because of the relative ease in obtaining purified protein in abundance, AceytlCholinesterase was first crystallized by Joel Sussman of the Weizmann Institute, Rehovot Israel, after being extracted from the electric organ of the Pacific Sting Ray, '''Torpedo Californica''', order to determine its detailed | Because of the relative ease in obtaining purified protein in abundance, AceytlCholinesterase was first crystallized by Joel Sussman of the Weizmann Institute, Rehovot Israel, after being extracted from the electric organ of the Pacific Sting Ray, '''Torpedo Californica''', order to determine its detailed | ||
3-dimensional structure by X-ray crystallography ([[2ace]]). Subsequently its X-ray structure has been determined from over 20 species, ranging from the fruit fly '''Drosophila''' to human. | 3-dimensional structure by X-ray crystallography ([[2ace]]). Subsequently its X-ray structure has been determined from over 20 species, ranging from the fruit fly '''Drosophila''' to human. | ||
<applet load='1ea5' size='200' color='white' frame='true' spin='off' caption='here is the caption' align='right' /> | <applet load='1ea5' size='200' color='white' frame='true' spin='off' caption='here is the caption' align='right' /> | ||
Acetylcholinesterase is a fairly large protein, consisting of at least 535 amino acid residues in a single peptide chain, that folds into a single protein domain without any apparent symmetry. <scene name='Acetylcholinesterase/1eaf_2ndary/1'>At its core are two large Beta sheets (green), surrounded | Acetylcholinesterase is a fairly large protein, consisting of at least 535 amino acid residues in a single peptide chain, that folds into a single protein domain without any apparent symmetry. <scene name='Acetylcholinesterase/1eaf_2ndary/1'>At its core are two large Beta sheets (green), surrounded by a canopy of about 26 alpha helices (red). </scene> | ||
by a canopy of about 26 alpha helices (red). </scene> | |||
The active site region of this enzyme has two sites, a catalytic site and a peripheral site, which helps prebind the substrate and direct it toward the active site. When the 3-D structure was first determined, the big surprise was | The active site region of this enzyme has two sites, a catalytic site and a peripheral site, which helps prebind the substrate and direct it toward the active site. When the 3-D structure was first determined, the big surprise was | ||
