title: Soluble scute proteins of healthy and ill desert tortoises (Gopherus agassizii).
abstract: OBJECTIVE
  To characterize protein composition of shell scute of desert tortoises and to determine whether detectable differences could be used to identify healthy tortoises from tortoises with certain illnesses.
  
  
  METHODS
  20 desert tortoises.
  
  
  METHODS
  Complete postmortem examinations were performed on all tortoises. Plastron scute proteins were solubilized, scute proteins were separated by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and proteins were analyzed, using densitometry. Two-dimensional immobilized pH gradient-PAGE (2D IPG-PAGE) and immunoblot analysis, using polyclonal antisera to chicken-feather beta keratin and to alligator-scale beta keratin, were conducted on representative samples. The 14-kd proteins were analyzed for amino acid composition.
  
  
  RESULTS
  The SDS-PAGE and densitometry revealed 7 distinct bands, each with a mean relative protein concentration of > 1 %, ranging from 8 to 47 kd, and a major protein component of approximately 14 kd that constituted up to 75% of the scute protein. The 2D IPG-PAGE revealed additional distinct 62- and 68-kd protein bands. On immunoblot analysis, the 14-, 32-, and 45-kd proteins reacted with both antisera. The 14-kd proteins had an amino acid composition similar to that of chicken beta keratins. There was a substantial difference in the percentage of the major 14-kd proteins from scute of ill tortoises with normal appearing shells, compared with 14-kd proteins of healthy tortoises.
  
  
  CONCLUSIONS
  The major protein components of shell scute of desert tortoises have amino acid composition and antigenic features of beta keratins. Scute protein composition may be altered in tortoises with certain systemic illnesses.
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, University of Florida, Gainesville, 32610, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Homer
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: K H
authors.initials: KH
authors.lastname: Berry
authors.forename: N D
authors.initials: ND
authors.lastname: Denslow
authors.forename: E R
authors.initials: ER
authors.lastname: Jacobson
authors.forename: R H
authors.initials: RH
authors.lastname: Sawyer
authors.forename: J E
authors.initials: JE
authors.lastname: Williams
mesh_terms: D000820:Animal Diseases / Q000473:pathology; D000818:Animals; D002140:California; D003120:Colorado; D004268:DNA-Binding Proteins / Q000032:analysis*; D003889:Desert Climate; D029721:Drosophila Proteins; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D012016:Reference Values; D012867:Skin / Q000737:chemistry* / Q000473:pathology; D012995:Solubility; D014157:Transcription Factors / Q000032:analysis*; D014426:Turtles
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors; C089197:sc protein, Drosophila