IDENTIFICATION, CHARACTERIZATION, AND DEVELOPMENTAL PROFILE OF A HIGH-MOLECULAR-WEIGHT, JUVENILE HORMONE-BINDING PROTEIN IN THE HEMOLYMPH OF THE MIGRATORY GRASSHOPPER, MELANOPLUS-SANGUINIPES

In the hemolymph of Melanoplus sanguinipes, a high molecular weight juvenile hormone binding protein (JHBP) was identified by photoaffinity labelling and found to have a M(r) of 480,000. The JHBP, purified using native gel electrophoresis followed by electroelution, has an equilibrium dissociation constant for JH III of 2.1 nM and preferentially binds JH III over IH I. Antibody raised against JHBP recognized only the 480,000 band. Under denaturing conditions the native JHBP gave a single band with a M(r) 78,000. The antibody against native JHBP recognized only the 78,000 protein in SDS-treated hemolymph samples, indicating that JHBP is a hexamer in this species. The concentration of JHBP fluctuates in both the sexes during nymphal and adult development in parallel with total protein content of hemolymph. (C) 1995 Wiley-Liss, Inc.