Root effect of Panulirus interruptus hemocyanin.
Panulirus interruptus hemocyanin exhibits a progressive decrease in oxygen affinity and a parallel loss of cooperativity with decrease in pH, resulting in an apparent loss of the oxygen-binding capacity of the protein. For a characterization of this system, oxygen-binding curves have been determined over the complete range of oxygen saturation, applying a special technique which involves high-pressure spectrophotometry. Although the oxygen-binding behavior as a function of pH is complex and cannot be described within the frame of a simple two-state Monod-Wyman-Changeux model, the observed Root effect is clearly related to a progressive stabilization of a low oxygen affinity state of the protein and functional heterogeneity is not apparent.
D000818:Animals; D001665:Binding Sites; D006433:Hemocyanins; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D008121:Nephropidae / Q000502:physiology*; D010100:Oxygen; D013056:Spectrophotometry, Ultraviolet
D006433:Hemocyanins; D010100:Oxygen