Nom du corpus

Corpus Systématique Animale

Titre du document

A comparison of lizard claw keratin proteins with those of avian beak and claw

Lien vers le document
Springer (journals)
Langue(s) du document
Type de document
Mots-clés d'auteur
  • Varanus
  • Lizard
  • Claw
  • Keratin
  • Electrophoresis
  • Protein
  • Fractionation
  • Glycine
  • Tryptophan
Nom du fichier dans la ressource
Mammiferes_v2b_02346, Oiseaux_v2b_02507, Reptiles_v2b_00796
  • J. M. Gillespie 1
  • R. C. Marshall 1
  • E. F. Woods 1
  • 1) Division of Protein Chemistry, CSIRO, 343 Royal Parade, 3052, Parkville, Victoria, Australia

The outer shell of translucent keratin has been dissected from the claws of the lizard,Varanus gouldii. It is free of calcium and hydroxyproline, in contrast to the fibrous support, and contains proteins rich in glycine (28 residues %) and half-cystine (13%). These proteins have been obtained in soluble form by treatment with 2-mercaptoethanol in 8M urea at pH 11 followed by alkylation with iodoacetate to giveS-carboxymethyl kerateines. The three major components resolved by SDS polyacrylamide gel electrophoresis have been isolated by fractional precipitation with ammonium sulfate followed by chromatography on DEAE-cellulose or Sephadex. Two of the components, low in tryptophan content, appear to be homologous and are relatively homogeneous with respect to both size and charge whereas the third, a tryptophan-rich material, appears to contain about 20 different molecular species as judged by gel electrophoresis in urea at pH 8.9. The molecular weights of two of the isolated omponents (the tryptophan-rich and the major of the two tryptophanpoor components) are about 13000 as determined by equilibrium ultracentrifugation studies. The major lizard claw proteins are therefore similar in size and glycine content to the proteins of avian beak and claw but differ in containing more cystine and less tyrosine. On the other hand, the reptilian proteins resemble the mammalian high-tyrosine proteins (Type II) in cystine content and overall amino acid composition, but differ in size with the lizard proteins being larger. It is suggested however that they are unlikely to be homologous.

Catégories Science-Metrix
  • 1 - natural sciences
  • 2 - biology
  • 3 - evolutionary biology
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Genetics
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Molecular Biology
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics
Catégories WoS
  • 1 - science ; 2 - genetics & heredity
  • 1 - science ; 2 - evolutionary biology
  • 1 - science ; 2 - biochemistry & molecular biology
Identifiant ISTEX

Journal of Molecular Evolution

Année de publication
Présence de XML structuré
Version PDF
Score qualité du texte
  • Mammiferes
  • Oiseaux
  • Reptiles
Type de publication
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