Temperature adaptation influences the aggregation state of hemocyanin fromAstacus leptodactylus

When Astacus leptodactylus were kept at various temperatures for several we eks, different ratios between di-hexameric and hexameric hemocyanins were o bserved in their hemolymph. The higher the temperature the more hexamers we re present. This long-term adaptation to different temperatures or/and to t emperature-induced pH-shifts as observed in the hemolymph has different eff ects on the expression of subunit types building up hexamers and those whic h covalently link two hexamers within the di-hexamers. The oxygen binding b ehaviour of di-hexameric hemocyanins from cold and warm adapted animals do not show differences with respect to affinity, Bohr effect and cooperativit y. (C) 2000 Elsevier Science Inc. All rights reserved.