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: firstname.lastname@example.org ). 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
AJP - Regulatory, Integrative and Comparative Physiology – The American Physiological Society
Published: Nov 1, 2002
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera