title: NMR spectroscopy reveals the presence and association of lipids and keratin in adhesive gecko setae.
abstract: Lipid and protein aggregates are one of the fundamental materials of biological systems. Examples include cell membranes, insect cuticle, vertebrate epidermis, feathers, hair and adhesive structures known as 'setae' on gecko toes. Until recently gecko setae were assumed to be composed entirely of keratin, but analysis of footprints left behind by geckos walking on surfaces revealed that setae include various kinds of lipids. However, the arrangement and molecular-level behavior of lipids and keratin in the setae is still not known. In the present study we demonstrate, for the first time, the use of Nuclear Magnetic Resonance (NMR) spectroscopy techniques to confirm the presence of lipids and investigate their association with keratin in 'pristine' sheds, or natural molts of the adhesive toe pad and non-adhesive regions of the skin. Analysis was also carried on the sheds after they were 'delipidized' to remove surface lipids. Our results show a distribution of similar lipids in both the skin and toe shed but with different dynamics at a molecular level. The present study can help us understand the gecko system both biologically and for design of synthetic adhesives, but the findings may be relevant to the characteristics of lipid-protein interactions in other biological systems.
authors.affiliation: Department of Polymer Science, The University of Akron, Akron, OH 44325-3909, USA.
authors.forename: Dharamdeep
authors.initials: D
authors.lastname: Jain
authors.affiliation: Department of Biology, Integrated Bioscience Program, The University of Akron, Akron, OH 44325-3908, USA.
authors.forename: Alyssa Y
authors.initials: AY
authors.lastname: Stark
authors.affiliation: Department of Biology, Integrated Bioscience Program, The University of Akron, Akron, OH 44325-3908, USA.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Niewiarowski
authors.affiliation: Department of Polymer Science, The University of Akron, Akron, OH 44325-3909, USA.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Miyoshi
authors.affiliation: Department of Polymer Science, The University of Akron, Akron, OH 44325-3909, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Dhinojwala
mesh_terms: D000818:Animals; D002855:Chromatography, Thin Layer; D007633:Keratins / Q000032:analysis / Q000378:metabolism*; D008055:Lipids / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D019906:Nuclear Magnetic Resonance, Biomolecular; D012104:Reptiles / Q000378:metabolism*; D012867:Skin / Q000378:metabolism
chemical_list: D008055:Lipids; D007633:Keratins