Molecular Models of Peptides


Mellittin

The principal component of honey bee venom. A strongly basic polypeptide due to the presence of two Arg and two Lys near the C-terminal end. The crystal structure shows a tetramer made up of four identical α-helical monomers. This model is a dimer, representing half of the tetramer.
The only significant secondary structure in each chain is the α-helix. Hydrophobic surfaces near the center of each chain cluster together in the tetramer.

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Show Hydrophobic Surface (orange)
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Lysozyme

A mucolytic enzyme with antibiotic properties. This is a typical globular protein, incorporating an assortment of large and small alpha-helices and a few short beta-sheets. There are also four disulfide bonds.

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A Cyclic Peptide

This 21 residue peptide has a ring formed by an amide bond from the aspartic acid side chain (residue #9) to the N-terminal cysteine. There are also two disulfide bonds (Cys1-Cys13 & Cys7-Cys19). The backbone trace (4th button below) does not join the Asp to Cys1. This compound has been found to be an inhibitor of the HIV virus.

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