The intracellular coelomic haemoglobin of Heteromastus filiformis was studied. The haemoglobin is heterogeneous on the basis of isoelectric point. The four main components have i.e.p 5,86; 6,13; 6,95; 7,15. The molecular weight is between 6.000 and 10.000 Daltons. The 02 affinity is high (P50 ~ 9 N.m-2 for whole and haemolysed coelomic fluid and ~ 3,3 N.m-2 for stripped haemoglobin; 15°C, pH 7,4). The Bohr factor is -0,34. There is a distinct Root-effect at pH < 6. The Hill-plots show a downward crack near 50% saturation, with slight to marked cooperativity below 50% saturation and none to slight cooperativity above 50 %. An association-dissociation equilibrium is suggested. ATP has an effect on O2-binding, but there probably are rather modificators. The results are discussed in relation to the measured environmental parameters. |
