Sandbox Reserved 466: Difference between revisions
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Tetanus toxin enters the bloodstream or directly binds with a neuronal cell after entering the body from a cut or abrasion. It binds to the neural cells through gangliosides and a protein receptor. Once bound, they enter the cytosol of the synaptic cleft of muscle fiber neurons via a vesicle membrane. Here, they attack and cleave the protein that forms the synaptic vesicle fusion apparatus, particularly [http://en.wikipedia.org/wiki/Synaptobrevin synaptobrevin] [Rao et al., 2005]. Synaptobrevin is a protein that forms [http://en.wikipedia.org/wiki/SNARE_proteins SNARE proteins], which mediate the fusion of synaptic vesicles to the presynaptic terminal. The clostridial neurotoxins each have unique binding sites and substrate cleavage specificity. Tetanus toxin cleaves vesicle-associated membrane proteins of synaptobrevin and inactivates it. The VAMP protein is cleaved at the peptide bond Gln76-Phe77 requiring a amino-terminal extension of 22 residues and a peptide of 33-97 residues in length [Rao et al., 2005]. | Tetanus toxin enters the bloodstream or directly binds with a neuronal cell after entering the body from a cut or abrasion. It binds to the neural cells through gangliosides and a protein receptor. Once bound, they enter the cytosol of the synaptic cleft of muscle fiber neurons via a vesicle membrane. Here, they attack and cleave the protein that forms the synaptic vesicle fusion apparatus, particularly [http://en.wikipedia.org/wiki/Synaptobrevin synaptobrevin] [Rao et al., 2005]. Synaptobrevin is a protein that forms [http://en.wikipedia.org/wiki/SNARE_proteins SNARE proteins], which mediate the fusion of synaptic vesicles to the presynaptic terminal. The clostridial neurotoxins each have unique binding sites and substrate cleavage specificity. Tetanus toxin cleaves vesicle-associated membrane proteins of synaptobrevin and inactivates it. The VAMP protein is cleaved at the peptide bond Gln76-Phe77 requiring a amino-terminal extension of 22 residues and a peptide of 33-97 residues in length [Rao et al., 2005]. | ||
This interaction between the residues, water, and zinc are essential for the formation of nucleophilic water, which hydrolyzes the peptide bonds of the substrate. | This interaction between the residues, water, and zinc are essential for the formation of nucleophilic water, which hydrolyzes the peptide bonds of the substrate. The three amino acids His232, His236, and Glu270 directly coordinate with the zinc ion. A water molecule, which is the fourth ligand, forms a strong hydrogen bond with another glutamate residue (Glu233) that is part of the secondary surrounding active residues. The | ||
