Studies on Invertebrate Hemoglobins (erythrocruorins)

1. Two high molecular invertebrate hemoglobins (the erythrocruorins of Lumbricus terrestris and of Nereis virens) as well as the low molecular erythrocruorin of Glycera dibranchiata Ehlers were studied. Their physical chemical properties were compared with those of vertebrate hemoglobin. 2. The hemin of the blood pigment of Glycera dibranchiata Ehlers was shown to be identical with that of vertebrate hemoglobin. 3. The dissociation rates of Glycera and human oxyhemoglobin were measured in the reaction meter of DuBois and t(50) (half time of the reaction) was found to be identical (0.027 second) for the two pigments. The t(50) value for the high molecular Lumbricus erythrocruorin was 0.070 second. 4. The chemical constitution and physical chemical properties of erythrocruorins were compared with those of vertebrate hemoglobin and of hemocyanin.