Functional multiplicity and structural correlations in the hemoglobin system of larvae of Chironomus thummi thummi (Insecta, Diptera): Hb components CTT I, CTT II beta, CTT III, CTT IV, CTT VI, CTT VIIB, CTT IX and CTT X.
Larvae of the dipteran insect Chironomus thummi thummi that burrow in fresh-water muds, contain at least 12 hemoglobin (Hb) components of which the functional properties have not been systematically documented, although their amino acid sequences have been elucidated, showing mutually distinct primary structures. We isolated eight components (the monomeric Hbs CTT I, CTT III and CTT IV and the dimeric Hbs CTT II beta, CTT VI, CTT VIIB, CTT IX and CTT X) and measured in each O2 affinity and cooperativity and their pH dependence, and the effects of temperature, NaCl and ATP. The O2 affinities, Bohr- and temperature effects of the isohemoglobins are discussed in relation to mode of life and the microenvironmental conditions to which the larvae are subjected in nature, and with regard to the molecular mechanisms underlying the Hb-oxygenation reactions.
D000818:Animals; D002683:Chironomidae / Q000502:physiology*; D004175:Diptera / Q000502:physiology*; D006454:Hemoglobins / Q000302:isolation & purification* / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007814:Larva / Q000502:physiology; D046911:Macromolecular Substances; D010108:Oxyhemoglobins / Q000302:isolation & purification
D006454:Hemoglobins; D046911:Macromolecular Substances; D010108:Oxyhemoglobins