Photoaffinity Labelling of Juvenile Hormone-Binding Proteins in Leucophaea maderae

Abstract

Juvenile hormone (JH) binding proteins have been identified in tissues from several insect species [1–3]. In the adult female cockroach Leucophaea maderae, JH-binding proteins have been found in the fat body [4], ovaries [5], and hemolymph [4,5]. Although some properties of these binding proteins have been described, further characterization has been hampered by the extremely rapid dissociation of JH from the binding protein under nonequilibrium conditions. In an attempt to circumvent this problem, we have initiated studies on the possible use of a photoactivatable JH III analog (Fig. 1), 10,11-epoxyfarnesyl diazoacetate (EFDA), to form an irreversible covalent attachment at the JH binding site on the hormone binding protein. Our preliminary investigations suggested that EFDA covalently attached to JH-binding proteins in the hemolymph and ovaries [6]. Recent studies have focused on the specificity of [3H]-EFDA binding to both the hemolymph and the ovarian binding proteins.