Purification and characterization of a juvenile hormone binding protein from hemolymph of the silkworm, Bombyx mori.
A juvenile hormone binding protein (JHBP) has been isolated from Bombyx mori hemolymph by gel filtration, ion-exchange chromatography, chromatofocusing and hydroxyapatite column chromatography. Gel electrophoresis indicates that the isolated protein is homogeneous in the presence or absence of a denaturing agent. The JHBP in question has a relative molecular mass of 32 kDa, determined by denaturing gel electrophoresis. Chromatofocusing analysis indicated that the JHBP is an acidic protein with pI 4.9. The protein exhibits a dissociation constant of 9.0 x 10(-8) M for JH I, 1.14 x 10(-7) M for JH II and 3.9 x 10(-7) M for JH III, and thus its affinity for JH analogues is in the order of JH I > JH II > JH III. Its amino acid composition indicates that the protein consists of 297 residues of 18 kinds of amino acids. The sequence of the N-terminus of the polypeptide chain was determined for 34 of the first 36 residues: Asp-Gln-Asp-Ala-Leu-Leu- Lys-Pro-?-Lys-Leu-Gly-Asp-Met-Gln-Ser-Leu-Ser-Ser-Ala-Thr-Gln-Gln-Phe-Le u-Glu- Lys-Thr-Ser-Lys-Gly-Ile-Pro-?-Tyr-His-.
Kurata
K
K
Department of Insect Physiology and Behavior, National Institute of Sericultural and Entomological Science, Ibaraki, Japan.
Nakamura
M
M
Okuda
T
T
Hirano
H
H
Shinbo
H
H
D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000378:metabolism*; D002352:Carrier Proteins / Q000302:isolation & purification*; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D006458:Hemolymph / Q000737:chemistry*; D019476:Insect Proteins; D007605:Juvenile Hormones / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight
D002352:Carrier Proteins; D019476:Insect Proteins; D007605:Juvenile Hormones; C035606:juvenile hormone-binding protein, insect