title: Extreme thermostability of tarantula hemocyanin.
abstract: Biotops with extreme temperatures such as deserts force animals to avoid or escape high temperatures by biochemical, behavioural or morphological adaptation. In this context we tested the resistance to heat of the oxygen carrier hemocyanin from the ancient tarantula Eurypelma californicum, which is found in arid zones of North America. Differential scanning calorimetry, light scattering, crossed immunogelelectrophoresis and oxygen binding experiments show that the 24-meric hemocyanin is conformationally stable and fully functioning at temperatures up to 90 degrees C. Our results demonstrate that the cation-mediated state of oligomerization is not only crucial for the high cooperativity of oxygen binding of this hemocyanin, but also for its extreme stability in the physiological temperature and pH range.
authors.affiliation: Dept. of Biophysical Chemistry, University of Basel, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Sterner
authors.forename: T
authors.initials: T
authors.lastname: Vogl
authors.forename: H J
authors.initials: HJ
authors.lastname: Hinz
authors.forename: F
authors.initials: F
authors.lastname: Penz
authors.forename: R
authors.initials: R
authors.lastname: Hoff
authors.forename: R
authors.initials: R
authors.lastname: Föll
authors.forename: H
authors.initials: H
authors.lastname: Decker
mesh_terms: D000222:Adaptation, Physiological; D000494:Allosteric Regulation; D000818:Animals; D002152:Calorimetry, Differential Scanning; D002413:Cations, Divalent / Q000494:pharmacology; D006433:Hemocyanins / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008027:Light; D010100:Oxygen / Q000378:metabolism; D011487:Protein Conformation; D011489:Protein Denaturation; D012542:Scattering, Radiation; D013112:Spiders / Q000737:chemistry* / Q000502:physiology; D013329:Structure-Activity Relationship
chemical_list: D002413:Cations, Divalent; D006433:Hemocyanins; D010100:Oxygen