Amyloid beta: Difference between revisions
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Amyoloid beta is actually the <scene name='Amyloid_beta/C-term/1'>C-terminal</scene> of the <scene name='Amyloid_beta/App/1'>Amyloid Precursor Protein</scene> which is a type I membrane-spanning glycoprotein encoded on chromosome 21 [[http://proteopedia.org/wiki/index.php/Amyloid_precursor_protein APP]].<ref name="alz" /> Amyloid beta results from an abnormal cleavage by [http://proteopedia.org/wiki/index.php/Beta_secretase beta-secretase] at the N-terminal and gamma-secretase at the C-terminal[[http://en.wikipedia.org/wiki/Beta_amyloid]]. The cleavage is nonspecific and results in peptides 39-43 amino acids in length, with 42 being the most common. Such cleavages occur most commonly in the plasma membrane though it can also occur in neuronal membranes.<ref name="alz" /> | Amyoloid beta is actually the <scene name='Amyloid_beta/C-term/1'>C-terminal</scene> of the <scene name='Amyloid_beta/App/1'>Amyloid Precursor Protein</scene> which is a type I membrane-spanning glycoprotein encoded on chromosome 21 [[http://proteopedia.org/wiki/index.php/Amyloid_precursor_protein APP]].<ref name="alz" /> Amyloid beta results from an abnormal cleavage by [http://proteopedia.org/wiki/index.php/Beta_secretase beta-secretase] at the N-terminal and gamma-secretase at the C-terminal[[http://en.wikipedia.org/wiki/Beta_amyloid]]. The cleavage is nonspecific and results in peptides 39-43 amino acids in length, with 42 being the most common. Such cleavages occur most commonly in the plasma membrane though it can also occur in neuronal membranes.<ref name="alz" /> | ||
The first 16 residues, Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu--Val-His-His-Gln-Lys, are mostly hydrophobic | The first 16 residues, Asp-Ala-Glu-Phe-Arg-His-Asp-Ser-Gly-Tyr-Glu--Val-His-His-Gln-Lys, are mostly hydrophobic with <scene name='Amyloid_beta/Cu/1'>His13 and His14</scene> form a binding domain for Cu(II). Residues 12-23 function as the <scene name='Amyloid_beta/Self/1'>self recognition</scene> region allowing for the formation of dimers and/or oligomers. This region also serves as the binding site for cholesterol, apolipoproteinE, alpha7nAChr, and amyloid beta-peptide binding alcohol dehydrogenase.<ref name="alz" /> | ||
The most reasonable structure determined structure consists of <scene name='Amyloid_beta/Two_helices/1'>two helices</scene>; the first helix (residues 8-25) is well defined and has an RMSD of 0.38 angstroms and the second (residues 28-38) is interrupted at the Ile32-Gly33 connection. The second helix corresponds to the transmembrane region of APP and thus contains multiple small and hydrophobic amino acids. The two helices are connected by a <scene name='Amyloid_beta/Kink/1'>kink</scene> (residues 26 and 27).<ref name="structure" /> | The most reasonable structure determined structure consists of <scene name='Amyloid_beta/Two_helices/1'>two helices</scene>; the first helix (residues 8-25) is well defined and has an RMSD of 0.38 angstroms and the second (residues 28-38) is interrupted at the Ile32-Gly33 connection. The second helix corresponds to the transmembrane region of APP and thus contains multiple small and hydrophobic amino acids. The two helices are connected by a <scene name='Amyloid_beta/Kink/1'>kink</scene> (residues 26 and 27).<ref name="structure" /> | ||