A synthetic analogue of melittin aggregates in large oligomers.
An analogue of melittin synthesized in the group of E. T. Kaiser (DeGrado, W. F., F. J. Keźdy, and E. T. Kaiser. 1981. J. Am. Chem. Soc. 103:679-681) was investigated by Raman spectroscopy and fluorescence anisotropy decay. In water, the analogue is completely alpha-helical and aggregates in large oligomers of about 50 monomers. In vesicle membranes, it undergoes orientational fluctuations similar to melittin. The most significant difference from melittin, therefore, is the formation of straight helixes and their aggregation in large oligomers in water. We interpret this as a consequence of the lacking proline residue in the analogue. We, furthermore, hypothesize that the increased tendency for aggregation causes the increased hemolytic activity of the analogue.
John
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Max-Planck-Institut für Biologie, Tübingen, Germany.
Jähnig
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D055592:Biophysical Phenomena; D001703:Biophysics; D005454:Fluorescence Polarization; D006460:Hemolysin Proteins; D046911:Macromolecular Substances; D008555:Melitten / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D013059:Spectrum Analysis, Raman; D014867:Water
D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D014867:Water; D008555:Melitten; C025994:delta hemolysin protein, Staphylococcus aureus