title: [Expression of human 17 beta-hydroxysteroid dehydrogenase gene in BmNPV expression system].
abstract: Estrogenic 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) plays a crucial role in the synthesis of estrogens, but it also produces negative action of estrogens in promoting the growth of hormone-sensitive cancers, especially in breast and prostate. The high specific activity can be taken as an important signal for the diagnosis of cancers. Recombinant rAcBm-NPV/17 beta-HSD virus which contains the human 17 beta-HSD cDNA under the control of polyhedron gene promoter is generated by cotransfection of the BmN cells with the transfer plasmid pVL/17 beta-HSD and wild BmNPV genomic DNA. 17 beta-HSD is maximally expressed 72 h and 120 h post infection in BmN cells and the 5th instar silkworm larvae respectively. At those time interval, intracellular and hemolymphic enzymatic activity reach 0.12 U/mg and 0.15 U/mg of protein which produced total activity of 0.97 U/1.5 x 10(6) cells and 4.7 U/larva. The expressed quantities in female larvae are a little higher than that in male larvae. The present data shows that Silkworm/BmNPV expression system can express 3-5 times higher than that of the richest human placenta. It also indicates that there is an apparent band with a molecular mass of 35 kDa using SDS-PAGE method, the size of which is similar to that of the crude enzyme from placenta.
authors.affiliation: Shanghai Institute of Biochemistry, Chinese Academy of Sciences.
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.forename: W
authors.initials: W
authors.lastname: Jin
authors.forename: X F
authors.initials: XF
authors.lastname: Wu
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000096:biosynthesis*; D000818:Animals; D012831:Bombyx / Q000378:metabolism*; D005260:Female; D006458:Hemolymph / Q000378:metabolism*; D008297:Male
chemical_list: D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase