In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
Also appears in:
De Blok, J.W.; Dorrestein, R.; Nienhuis, P.H.; Postma, H.; Weber, R.E. (Ed.) (1973). 7th European Symposium on Marine Biology, Texel, 11-16 September 1972. Netherlands Journal of Sea Research, 7. Netherlands Institute for Sea Research: Texel. 505 pp., more
Oxygen-binding and some molecular properties are reported for the Hb of Glycera gigantea, which contrasts to that in most annelids in being extravascular and intracellular. The O2 affinity of Hb in whole coelomic fluid is moderately high (P50 ± 7 mm). The O2 equilibrium curve is slightly sigmoid (n=1.4 to 1.8). Variation in pH effects neither P50 (no Bohr effect) nor n, and the temp sensitivity of O2-binding indicates an apparent heat of oxygenation (Delta H) of approx. or equal to -13 kcal/mole. At acid pH added ATP decreases the O2-affinity analogous to the influence of organic phosphates in vertebrates, but this effect is slight and its functional significance is questionable. Glycera red cells appear to contain tetrameric as well as monomeric Hb. On the basis of iso-electric point the Hb resolves into numerous components. Four main components isolated preparatively show marked differentiation in oxygen affinity. The results are discussed in relation to the burrowing habitat and compared with available data on Hb from the American G. dibranchiata and the high molecular annelid Hbs.