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|Type:||Artigo de periódico|
|Title:||Content Of Organic Polyphosphates And Their Allosteric Effects On Haemoglobins From The Water-snakes Helicops Modestus And Liophis Miliaris|
Focesi Jr. A.
|Abstract:||1. 1. The ion-exchange Chromatographie analysis of the red cell nucleotides of two water-snakes with different degrees of adaptation to water showed a ratio ATP/GTP of about 2.3 in the more aquatic species Helicops modestus and of about 0.7 in Liophis miliaris. 2. 2. The haemoglobin oxygen affinity assayed in the presence of ATP, GTP, DPG and IHP in haemolysate from both snakes were determined as a function of pH. The Bohr effect values were always found to be increased in comparison with the stripped haemolysate, becoming about 1.5 times higher in L. miliaris compared with H. modestus by the nucleotide treatment. 3. 3. The Hill coefficient calculated from the slope of the haemoglobin binding curves was consistent with an increase in the protein cooperativity in the presence of the nucleotides assayed. The very low nH values of about 1.2 in absence of the effectors became close to 2.0 in their presence. 4. 4. The data of nucleotide Chromatographie analysis were compared to those found in fishes with bimodal respiration. © 1984.|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
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