Circular dichroism studies on synthetic signal peptides indicate beta-conformation as a common structural feature in highly hydrophobic environment.
The conformations of synthetic peptides corresponding to signal sequences of chicken lysozyme and Escherichia coli proteins alkaline phosphatase and lipoprotein (wild-type) and their "variants" with a charged amino acid in the hydrophobic region, have been studied by circular dichroism spectroscopy in trifluoroethanol and micelles of sodium dodecyl sulfate, Brij 35, and sodium deoxycholate. In trifluoroethanol and aqueous mixtures of trifluoroethanol, the "wild-type" and variant signal sequences show similar conformational behavior. The wild-type signal peptides show increasing amounts of beta-structure going from sodium dodecyl sulfate to deoxycholate micelles (i.e. increasing order of hydrophobicity). The variant signal sequences, however, are largely unordered in micelles. The absence of beta-structure in variant signal sequences which do not initiate protein translocation across membranes, strongly suggests that the ability of signal sequences to adopt beta-structure in a highly hydrophobic environment is important for function.
Centre for Cellular and Molecular Biology, Hyderabad, India.
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D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D003840:Deoxycholic Acid; D007202:Indicators and Reagents; D008823:Micelles; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics; D011487:Protein Conformation; D021382:Protein Sorting Signals / Q000138:chemical synthesis; D012967:Sodium Dodecyl Sulfate
D007202:Indicators and Reagents; D008823:Micelles; D021382:Protein Sorting Signals; D003840:Deoxycholic Acid; D012967:Sodium Dodecyl Sulfate; D009113:Muramidase