Search results for "JH esterase"
showing 2 items of 2 documents
In vitro modeling of the ternary interaction in juvenile hormone metabolism
1996
The gradual decline in juvenile hormone (JH) titer followed by its complete clearance early in the last larval instar is required for the onset of the metamorphosis of lepidopterous larvae. JH titer is regulated by both biosynthesis and degradation. Two major pathways for JH metabolism, ester hydrolysis and epoxide hydration, are due to JH esterase (JHE) and JH epoxide hydrolase (JHEH), respectively. In vitro experiments designed to elucidate the molecular mechanism of JH metabolism are described. First, microsomal JHEH in Manduca sexta eggs was identified by using photoaffinity analogs of JH, and purified to homogeneity with ion exchange and hydroxylapatite columns. Purified JHEH from M. s…
Purification and reassessment of ligand binding by the recombinant, putative juvenile hormone receptor of the tobacco hornworm, Manduca sexta
1996
The 29 kDa protein from the larval epidermis of the tobacco hornworm, Manduca sexta, that specifically bound photoaffinity analogs of JH I and JH II was produced by a recombinant baculovirus (rJP29). The higher of the two molecular weight forms made corresponded to a protein that could be formed by read‐through of the TGA termination codon to the following TAA. The previously reported, apparent high affinity binding of [methyl‐3H]‐JH I by rJP29 as measured by the dextran‐coated charcoal (DCC) assay [Palli et al., Proc Natl Acad Sci USA 91:6191–6195 (1994)] was found to be artifactual due to endogenous cellular esterases that co‐purified with rJP29 through both DEAE cellulose and MonoQ chrom…