title: Structural proteins from whelk egg capsule with long range elasticity associated with a solid-state phase transition.
abstract: The robust, proteinaceous egg capsules of marine prosobranch gastropods (genus Busycotypus ) exhibit unique biomechanical properties such as high elastic strain recovery and elastic energy dissipation capability. Capsule material possesses long-range extensibility that is fully recoverable and is the result of a secondary structure phase transition from α-helical coiled-coil to extended β-sheet rather than of entropic (rubber) elasticity. We report here the characterization of the precursor proteins that make up this material. Three different proteins have been purified and analyzed, and complete protein sequences deduced from messenger ribonucleic acid (mRNA) transcripts. Circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy indicate that the proteins are strongly α-helical in solution and primary sequence analysis suggests that these proteins have a propensity to form coiled-coils. This is in agreement with previous wide-angle X-ray scattering (WAXS) and solid-state Raman spectroscopic analysis of mature egg capsules.
authors.affiliation: Biomolecular Sciences and Engineering Program, University of California , Santa Barbara, California 93106, United States.
authors.forename: S Scott
authors.initials: SS
authors.lastname: Wasko
authors.forename: Gavin Z
authors.initials: GZ
authors.lastname: Tay
authors.forename: Andreas
authors.initials: A
authors.lastname: Schwaighofer
authors.forename: Christoph
authors.initials: C
authors.lastname: Nowak
authors.forename: J Herbert
authors.initials: JH
authors.lastname: Waite
authors.forename: Ali
authors.initials: A
authors.lastname: Miserez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D004548:Elasticity / Q000502:physiology*; D008969:Molecular Sequence Data; D008974:Mollusca; D010063:Ovum / Q000737:chemistry* / Q000502:physiology*; D017433:Protein Structure, Secondary