Characterization of the carotenoid-binding protein of the Y-gene dominant mutants of Bombyx mori

Vertebrate and invertebrate carotenoid-binding proteins

“…Sequence identity of B. mori CBP and mouse MLN64 and human StAR protein was 29% and 25%, respectively, and high levels of StAR have been reported in carotenoid-rich tissues such as human corpus luteum [33][34]. The absorption spectrum of B. mori CBP was characterized by three absorbance maxima in the visible region at 436, 461, and 493 nm, a significant red shift of 22 nm compared with lutein's spectrum in hexane Its spectrum was very close to the reported absorption spectra of LBP isolated from the midgut of B. mori by Jouni and Wells [29,35], suggesting that silkworm LBP and CBP might be the same protein, although their reported stoichiometries of binding differ with a lutein to protein ratio of 3:1 for LBP and 1:1 for CBP. Functional characterization studies by microscopic immunocytochemistry clearly indicated that this protein might be involved in aiding absorption and uptake of carotenoids from lipophorin [35] which is ultimately responsible for pigmentation of the yellow cocoons [36].…”

Proteomic Studies of Isoforms of the P25 Component ofBombyx moriFibroin

“…1, the SG was dissected and divided into the following six parts: ASG, MSG1, MSG2, MSG3, MSG4 and PSG. 7) Proteins were extracted from each of these parts and resolved by 2DE in triple replicate. P25s were detected as stained spots within a range of molecular sizes between 30 kDa and 27 kDa.…”

“…1). 7) Every part of the SG was blotted on filter paper, frozen with liquid y To whom correspondence should be addressed. Fax: +81-92-621-1011; E-mail: Fujii@agr.kyushu-u.ac.jp Abbreviations: 2-DE, two-dimensional gel electrophoresis; MALDI-TOF MS, matrix-assisted laser desorption/ionization-time of flight mass spectrometry; PMF, peptide mass fingerprinting; SG, silk gland nitrogen, and stored at À80 C until use.…”

Polymorphism identification of carotenoid binding protein gene transcription in the silkworm, <i>Bombyx mori</i>

“…Carotenoids are supposed to be the major pigment contributing to yellow cocoon coloration, and the uptake of carotenoids into the intestinal mucosa and the silk gland is controled by the Y (Yellow blood) gene in Bombyx mori [4]. A carotenoid binding protein (CBP) was isolated from the silk gland of the fifth instar Bombyx larvae [2].…”

“…A carotenoid binding protein (CBP) was isolated from the silk gland of the fifth instar Bombyx larvae [2]. CBP can be only found in Y gene dominant strains (Y/Y) with yellow cocoons rather than recessive strains (+ Y /+ Y ) with white cocoons [3][4][5][6]. RFLP analysis of the genes showed that CBP and the Y-gene were at the same chromosome locus and they may correspond to each other [7].…”