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Novel mechanism for high-altitude adaptation in hemoglobin of the Andean frog Telmatobius peruvianus

Novel mechanism for high-altitude adaptation in hemoglobin of the Andean frog Telmatobius peruvianus Abstract In contrast to birds and mammals, no information appears to be available on the molecular adaptations for O 2 transport in high-altitude ectothermic vertebrates. We investigated Hb of the aquatic Andean frog Telmatobius peruvianus from 3,800-m altitude as regards isoform differentiation, sensitivity to allosteric cofactors, and primary structures of the α- and β-chains, and we carried out comparative O 2 -binding measurements on Hb of lowland Xenopus laevis . The three T. peruvianus isoHbs show similar functional properties. The high O 2 affinity of the major component results from an almost complete obliteration of chloride sensitivity, which correlates with two α-chain modifications: blockage of the NH 2 -terminal residues and replacement by nonpolar Ala of polar residues Ser and Thr found at position α131(H14) in human and X. leavis Hbs, respectively. The data indicate adaptive significance of α-chain chloride-binding sites in amphibians, in contrast to human Hb where chloride appears mainly to bind in the cavity between the β-chains. The findings are discussed in relation to other strategies for high-altitude adaptations in amphibians. amphibians chloride binding hypoxia organic phosphates oxygen transport Footnotes This work was supported by the Danish Natural Science Research Council and the Fund for Scientific Research Projects, Flanders, Belgium. Address for reprint requests and other correspondence: R. E. Weber, Dept. of Zoophysiology, Univ. of Aarhus, 131 C. F. Møllers Alle, DK 8000 Aarhus C, Denmark (E-mail: roy.weber@biology.au.dk ). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. August 22, 2002;10.1152/ajpregu.00292.2002 Copyright © 2002 the American Physiological Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png AJP - Regulatory, Integrative and Comparative Physiology The American Physiological Society

Novel mechanism for high-altitude adaptation in hemoglobin of the Andean frog Telmatobius peruvianus

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References (66)

Publisher
The American Physiological Society
Copyright
Copyright © 2011 the American Physiological Society
ISSN
0363-6119
eISSN
1522-1490
DOI
10.1152/ajpregu.00292.2002
pmid
12376398
Publisher site
See Article on Publisher Site

Abstract

Abstract In contrast to birds and mammals, no information appears to be available on the molecular adaptations for O 2 transport in high-altitude ectothermic vertebrates. We investigated Hb of the aquatic Andean frog Telmatobius peruvianus from 3,800-m altitude as regards isoform differentiation, sensitivity to allosteric cofactors, and primary structures of the α- and β-chains, and we carried out comparative O 2 -binding measurements on Hb of lowland Xenopus laevis . The three T. peruvianus isoHbs show similar functional properties. The high O 2 affinity of the major component results from an almost complete obliteration of chloride sensitivity, which correlates with two α-chain modifications: blockage of the NH 2 -terminal residues and replacement by nonpolar Ala of polar residues Ser and Thr found at position α131(H14) in human and X. leavis Hbs, respectively. The data indicate adaptive significance of α-chain chloride-binding sites in amphibians, in contrast to human Hb where chloride appears mainly to bind in the cavity between the β-chains. The findings are discussed in relation to other strategies for high-altitude adaptations in amphibians. amphibians chloride binding hypoxia organic phosphates oxygen transport Footnotes This work was supported by the Danish Natural Science Research Council and the Fund for Scientific Research Projects, Flanders, Belgium. Address for reprint requests and other correspondence: R. E. Weber, Dept. of Zoophysiology, Univ. of Aarhus, 131 C. F. Møllers Alle, DK 8000 Aarhus C, Denmark (E-mail: roy.weber@biology.au.dk ). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. August 22, 2002;10.1152/ajpregu.00292.2002 Copyright © 2002 the American Physiological Society

Journal

AJP - Regulatory, Integrative and Comparative PhysiologyThe American Physiological Society

Published: Nov 1, 2002

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