Linked Life Data

8158641

Source:http://linkedlifedata.com/resource/pubmed/id/8158641

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-5-13
pubmed:databankReference
pubmed:abstractText
The functional properties of the single haemoglobin (Hb) of Emperor penguin (Aptenodytes forsteri) have been investigated at different temperatures as a function of proton and organic phosphate concentration. The complete amino acid sequence has been established. Comparison with that of human HbA shows 12 substitutions in the contact regions of alpha beta dimers. In addition to overall similarities shared with most of the avian Hbs previously described, this Hb shows significant differences, which could be related to the peculiar behaviour of this penguin. In particular we may consider that: (1) the shape of the Bohr effect curve seems well adapted for gas exchange during very prolonged dives, preserving penguin Hb from a sudden and not controlled stripping of oxygen; (2) the very minor enthalpy change observed at lower pH could be an example of molecular adaptation, through which oxygen delivery becomes essentially insensitive to exposure to the extremely low temperatures of the environment. Moreover, the small alkaline Bohr effect has been found to be only chloride-linked, since the pH dependence of the oxygen affinity is totally abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha and beta-chains.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
237
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
615-21
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Adaptation to extreme environments: structure-function relationships in Emperor penguin haemoglobin.
pubmed:affiliation
Institute of Protein Biochemistry and Enzymology, C.N.R., Naples, Italy.
pubmed:publicationType
Journal Article