Study On The Expression And Functional Analysis Of Bombyxin B-4(Bbx-b4) Gene

Bombyxin is a5kD brain secretion peptide which belongs to the insulin family.The amino acid sequences of its heterodimer which comprises of A-chain and B-chainhas high homology with insulin-family peptides. The specific function of Bombyxinis still unknown, however, we can deduce some basic functions of the bombyxin, forexample, it might play a role in cell growth，proliferation and differentiation of everyphase and different tissue and involves in regulation of oogenesis and embryogeny byregulating cell proliferation and differentiation just like the growth factor. In addition,bombyxin may be connected with carbohydrate metabolism as its increasing relates toglucose titer of hemolymph. So it is significant to get abundant bombyxin for itsfunction researching.In this study, E.coli and Bombyx mori baculovirus expression system were usedrespectively to get bombyxin and researched the regulation of blood sugar of thebombyxin from the Bombyx mori. First，Bbx-b4was obtained by SOE-PCR andexpressed in E.coli with high efficiency and corresponding product was purified bypolyhedrin’s solubility in base and used to immunize New Zealand white rabbit to getpolyclonal antibody. BmNPV and pFastBac1-Bbx-b4recombinant which constructedby transposition recombination inoculated the fresh silkworm pupa after proliferatingthree generations in BmN cells. Western blotting was used to analyze the existence ofBbx-b4in BmN cells and pupa. The result of FCM showed that Bbx-b4quickenedBmN cell entering into S phase and facilitated cell growth. Regulating blood sugar inmice suggested Bbx-b4expressed in silkworm pupa had hpyerglycemic effect to somedegree. The results point out that Bbx-b4probombyxin has very big correlation incarbohydrate metabolism. All of the results provide experiment base for the formerdeduction;and using Silkworm bioreactor efficiently express system providefoundation of the bombyxin application.