Magainin 2
From Proteopedia
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==Introduction== | ==Introduction== | ||
Magainin are a class of antimicrobial peptides (AMPs) found in the African clawed frog Xenopus laevis. | Magainin are a class of antimicrobial peptides (AMPs) found in the African clawed frog Xenopus laevis. | ||
| - | AMPs consists of 10-50 amino acids, and are produced by Eukaryotes, as part of their defence mechanism from bacteria. For informatoin about | + | AMPs consists of 10-50 amino acids, and are produced by Eukaryotes, as part of their defence mechanism from bacteria. For informatoin about AMPs you can visit the Proteopedia page [[Antimicrobial peptides]] |
Magainin 1 and 2 were discovered by Dr. Michael Zasloff and first reported in 1987. They have an alpha helix structure, and are water soluble and Potentially amphiphilic. | Magainin 1 and 2 were discovered by Dr. Michael Zasloff and first reported in 1987. They have an alpha helix structure, and are water soluble and Potentially amphiphilic. | ||
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== Structural highlights == | == Structural highlights == | ||
| - | In general, amphipathic helical peptides that disrupt the ionic gradient of cells are thought to do so by forming ion channels assembled from 4–6 peptide molecules. | + | In general, amphipathic helical peptides that disrupt the ionic gradient of cells are thought to do so by forming ion channels assembled from 4–6 peptide molecules. Then the insides of the cell leak outside and the cell dies It was thought that this mechanism is also acountable for Magainin 2, But earlier solid-state NMR results show that its helix axis lies in the plane of phospholipid bilayers, suggesting that magainin’s mechanism for disrupting the ionic gradient may be fundamentally different. Therefor it's mechanism is still unclear. |
| - | + | Magainin 2 structure allows it to bind to membranes: | |
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Magainin 2, As typical to all AMPs, Is rich with <scene name='69/692248/Mag2_cationic_residues/2'>cationic residues</scene> that allow it to interact with Bacterial membranes, that are negatively charged in phosiological pH, and rich with <scene name='69/692248/Mag2_hydrophobic_residues/1'>Hydrophobic residues</scene> that allow it to interact with the membrane's phospholipids. | Magainin 2, As typical to all AMPs, Is rich with <scene name='69/692248/Mag2_cationic_residues/2'>cationic residues</scene> that allow it to interact with Bacterial membranes, that are negatively charged in phosiological pH, and rich with <scene name='69/692248/Mag2_hydrophobic_residues/1'>Hydrophobic residues</scene> that allow it to interact with the membrane's phospholipids. | ||
We can see <scene name='69/692248/Mag2_hydrophobic_and_cationic/1'>here</scene> that the residues are organised in it's alpha helix in a way that one side contains all hydrophobic residues (shown in green), and the other side contains all cationic residues (shown in purple). this probably helps Magainin 2 to bind to the bacterial membrane and perform it's antimicrobial action. | We can see <scene name='69/692248/Mag2_hydrophobic_and_cationic/1'>here</scene> that the residues are organised in it's alpha helix in a way that one side contains all hydrophobic residues (shown in green), and the other side contains all cationic residues (shown in purple). this probably helps Magainin 2 to bind to the bacterial membrane and perform it's antimicrobial action. | ||
Revision as of 18:03, 24 January 2015
Magainin 2
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