Magainin 2

Magainin 2

spinqualitylabelsall models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D This is a default text for your page Magainin 2. Click above on edit this page to modify. Be careful with the < and > signs. You may include any references to papers as in: the use of JSmol in Proteopedia or to the article describing Jmol to the rescue. Introduction 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 AMP you can visit the Proteopedia page Antimicrobial peptides  They were discovered by Dr. Michael Zasloff and first reported in 1987. Magainin and Magainin 2 Magainin and Magainin 2 were discovered together, and posses very similar sequences, of 23 Amino Acid long. Magainin: Gly-Ile-Gly-Lys-Phe-Leu-His-Ser-Ala-Gly-Lys-Phe-Gly-Lys-Ala-Phe-Val-Gly-Glu-Ile-Met-Lys-Ser magainin 2: Gly-Ile-Gly-Lys-Phe-Leu-His-Ser-Ala-Lys-Lys-Phe-Gly-Lys-Ala-Phe-Val-Gly-Glu-Ile-Met-Asn-Ser When the only difference is the 22th amino acid, Lys for Magainin and Asn for Magainin 2 Here we will debate abot Magainin 2 properties. Structural highlights The mechanism of how magainin 2 works is approximated to be the pore model, of which each single unit bind to the membrane and form a small pore, and when a few units bind to the membrane this way, the insides of the cell leak outside and the cell dies. Magainin 2 structure allows it to do so: Magainin 2, As typical to all AMPs, Is rich with cationic residues that allow it to interact with Bacterial membranes, that are negatively charged in phosiological pH, and rich with Hydrophobic residues that allow it to interact with the membrane's phospholipids. We can see here 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. Crystalization of Ala-Magainin So far we had shown Magainin 2 structure based only on NMR findings, Because helical AMPs crystallography is limited, since it is hard to form crystals. In the Hayouka et al., 2013, In order to perform crystallization of Magainin 2, changes in the sequence were maid, and Ala-Magainin 2 was contsructed. In Ala-magainin one Ser (S) and two Gly (G) residues have been changed to Ala (A) in order to increase helical propensity. These changes resulted in minor changes in the secondary structure. we can see here Magainin 2 residues that were changed to ala in Ala-Magainin (ala-magainin has a few more residues in alpha helix structure). This is a sample scene created with SAT to color by Group, and another to make a transparent representation of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.

Proteopedia Page Contributors and Editors (what is this?)

Carmit Ginesin, Michal Harel, Tal stern, Joel L. Sussman