6533b86dfe1ef96bd12c94d7
RESEARCH PRODUCT
A respiratory hemocyanin from an insect.
Wolfgang ErkerAxel SchoenJames H. MardenHeinz DeckerSilke Hagner-hollerRainer RupprechtThorsten Burmestersubject
DNA ComplementaryInsectamedicine.medical_treatmentProtein subunitmedia_common.quotation_subjectMolecular Sequence DataInsectBiologyEvolution MolecularCrustaceaHemolymphHemolymphmedicineAnimalsAmino Acid SequenceCloning MolecularNymphPhylogenymedia_commonchemistry.chemical_classificationMultidisciplinaryBase SequenceSequence Homology Amino AcidRespirationHemocyaninBiological SciencesAmino acidRespiratory proteinOxygenProtein SubunitschemistryBiochemistryHemocyaninsInsect ProteinsFemaleOxygen bindingdescription
Insects possess an elaborate tracheal system that enables transport of gaseous oxygen from the atmosphere directly to the inner organs. Therefore, the presence of specialized oxygen-transport proteins in the circulatory system of insects has been considered generally unnecessary. Here, we show for the first time, to our knowledge, the presence of an ancestral and functional hemocyanin (Hc) in an insect. In the hemolymph of nymphs and adults of the stonefly Perla marginata , a hexameric Hc was identified, which consists of two distinct subunit types of 659 and 655 amino acids. P. marginata Hc displays cooperative oxygen binding with a moderately high oxygen affinity [(half-saturation pressure, P 50 ≈8 torr (1 torr = 133 Pa)]. No evidence was found for the presence of Hcs in the more evolutionarily advanced holometabolan insects, suggesting that this type of respiratory protein was lost later in insect evolution. However, our results demonstrate that, in contrast to the accepted paradigm, certain basal insects have retained an ancestral blood-based mechanism of gas exchange.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2004-01-08 | Proceedings of the National Academy of Sciences of the United States of America |