Characterization of a juvenile hormone binding lipophorin from the blowfly Lucilia cuprina.
The larval haemolymph of the sheep blowfly Lucilia cuprina (Weidemann) contains a juvenile hormone binding protein with a Kd for racemic JH III of 33 +/- 6 nM. The density of the binding sites is 212 +/- 33 pmol/mg haemolymph protein. The binding protein is equally specific for JH III and methyl farnesoate. Some natural juvenoids were ranked for their ability to displace [3H]JH III with JH III > JH II > JH I > JH III acid > JH III diol > JHB3 = no detectable displacement. These data, together with displacement studies for 14 synthetic juvenoids, indicate some characteristics of the JH binding cleft. The binding protein is a high density lipophorin (density = 1.15 g/ml) and has subunit molecular weights of 228 kDa (apolipophorin I) and 70 kDa (apolipophorin II). The N-terminal amino acid sequences of the subunits have no discernible homology to any previously sequenced protein. Lipophorin-specific immunocytochemical staining occurs in a subset of fat body cells.
Trowell
S C
SC
CSIRO Division of Entomology, Canberra, Australia.
Hines
E R
ER
Herlt
A J
AJ
Rickards
R W
RW
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D004175:Diptera / Q000737:chemistry*; D007605:Juvenile Hormones / Q000378:metabolism*; D008024:Ligands; D008074:Lipoproteins; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D011485:Protein Binding
D002352:Carrier Proteins; D007605:Juvenile Hormones; D008024:Ligands; D008074:Lipoproteins; C032830:lipophorin