Oxygen affinity of avian hemoglobins

Studies on the Interaction of Organic Phosphates with Haemoglobin in an Amphibian (Bufo marinus), a Reptile (Trachydosaurus rugosus) and Man

“…Bartlett 1970). Inositol polyphosphates are known to be important modifiers in at least two species of birds and probably others (Bartlett 1970;Missen and Freeman 1972;Vandecasserie et al 1973). However, Johnson and Tate (1969) and Steward and Tate (1969) have shown that in two species the predominant inositol polyphosphate present is 1,3,4,5,6-myoinositol pentaphosphate and not the hexaphosphate previously reported.…”

“…The functional properties of haemoglobins from most classes of vertebrates have been shown to be modified by certain organic phosphates of the red blood cell cytoplasm* (Benesch et al 1968;Johnson and Tate 1969;Gillen and Riggs 1971;Wood 1971;Misson and Freeman 1972;Anderson et al 1973;Larkin 1973;Taketa and Nickerson 1973;Vandecasserie et al 1973;Geoghegan and Poluhowich 1974). The organic phosphates of the red blood cell cytoplasm so far shown to be modifiers of haemoglobin function are ADP, ATP, GTP, DPG (2,3-diphosphoglycerate), and myo-IP 5 (myo-inositol pentaphosphate).…”

Tertiary conformational transition in sheep hemoglobins induced by reaction with 5,5´-dithiobis(2-nitrobenzoate) and by binding of inositol hexakisphosphate

“…r⇌t or quaternary R⇌T transitions Heterotropic effector molecules -2,3-bisphosphoglycerate (2,3-BPG), inositol-P 6 and bezafibrate -lower the oxygen affinity of hemoglobin [28][29][30][31][32][33][34][35][36] and the reactivity of the CysF9[93]β sulphydryl group [22]. The interpretation of these results in terms of a shift in the equilibrium between the R and T quaternary states in favor of the T state has been questioned with respect to O 2 binding [32,33,35,36] and the reactivity of CysF9[93]β [14].…”

The Relationship Between Erythrocyte Phosphate Metabolism, Carbon Dioxide, and pH on Blood Oxygen Affinity in Birds

“…As 2,3-P2 -glycerate disappears from the red blood cells of the young chick, inositol-Ps and ATP concentrations begin to accumulate rapidly corresponding with marked decreases in blood oxygen afftnity (Isaacks and Harkness 1980). Inositol-Ps binds to avian and human hemoglobin, reducing oxygen afftnity and is, in fact, the most effective hemoglobin modulator occurring in animal red blood cells (Vandecasserie et al 1973; Is~cks and Harkness 1980), presumably functioning in birds in a manner similar to that of2,3-P2 -glycerate in the mammalian system.…”