Identify, Purification Of Soybean Lipoxygenases And Its Enzyme Charactteristics To Bleaching β-Carotene

Soybean lipoxygenase isozymes has a particular role in catalyzing the multi-unsaturated fatty acid that contain the structure of cis,cis-1,4-cyclopentadiene.It is essential to investigate the influence actors of indentification,purification and the bleaching activities of the soybean lipoxygenase toβ-carotene.We want to outline the mechanism of the lipoxygenase catalyzation and provide the theory for the soybean lipoxygenase application.Here we carry out the research in three aspects such as identification of the soybean lipoxygenase by SDS-PAGE,purification the isozymes and the characteristics of bleaching activities of the soybean lipoxygenase toβ-carotene.The conclusion as follows:We found that the SDS-PAGE identification test yields a good repeatability,therefore,it can be used to identify deletion mutants sample of soybean lipoxygenase.The best concentration of the polyacrylamide gel is 11%,the best time is 90min when bromophenol blue run over separation gel and the best volume of the sample is 5 uL.The pure soybean lipoxygenase can be collected by the crude soybean lipoxygenase passing the superdex75,Mono Q and RPC.The soybean lipoxygenase isozymes' bleaching activities onβ-carotene have different optimum conditions.0.05 M pH 6.8 Tris-HC1 buffer was best for extracting LOX1,LOX2, LOX3,LOX1,2 and LOX1,2,3,0.2 M pH 6.0 sodium phosphate buffer was the best suitable extract LOX1,3 and LOX2,3.The bleaching time of soybean lipoxygenase isozymes onβ-carotene could be bleached completely in 18 minutes.The LOX1,3 and LOX1,2,3's optimum temperature about this bleaching reaction were at 4℃,LOX2,LOX3 and LOX2,3 were at 27℃,LOX1,2 was at 50℃,LOX1 was at 80℃.LOX1 had the best bleaching effect in pH 9.0,LOX2 and LOX1,2,3 were in pH 6.8,LOX3,LOX1,2,LOX1,3 and LOX2,3 were in pH 7.0.These isozymes which were extracted within 6 hours bleachβ-carotene were stable except LOX2.