Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration ...Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Iα-loop-helix Iβmotif which corresponds to helix I of other P 450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,theγ-domain.The structure reveals a homodimer in which theγ-domain of one molecule interacts with theβ-domain of another.The plane of heme group makes an angle of approximately 40°with the helix Iα-loop-helix Iβmotif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recognition.Phe-301,Ser-303 and Gly-305 from the helix Iα-loop-helix Iβmotif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.展开更多
The latest results from our research group in the biotransformation of triptolides and bufadienolides were reviewed. The trends in the development of biotransformation in the future were also briefly discussed.
<Abstrcat> The contents of lignans glycosides in five species of \%Gaultheria \%Kalm ex L. were measured by HPLC. The resultes proved that 5 plants collected from same place all contain lignans glycosides (LD). ...<Abstrcat> The contents of lignans glycosides in five species of \%Gaultheria \%Kalm ex L. were measured by HPLC. The resultes proved that 5 plants collected from same place all contain lignans glycosides (LD). The contents of LD in the roots of different plants shows: \%G. fragrantissima>G. leucocarpa \%var. \%yunnanensis>G. leucocarpa \%var. \%cumingiana>G. tetramera>G. griffithiana, \%and these of the above\|ground parts indicate \%G. fragrantissima>G. leucocarpa \%var. \%yunnanensis\%. The contents of LD in the leaves of \%G. fragrantissima \%and \%G. leucocarpa \%var. \%cumingiana \%are higher than those in the stems, and that in stem of \%G. griffithiana \%higher than that in its leaf and root.展开更多
文摘Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Iα-loop-helix Iβmotif which corresponds to helix I of other P 450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,theγ-domain.The structure reveals a homodimer in which theγ-domain of one molecule interacts with theβ-domain of another.The plane of heme group makes an angle of approximately 40°with the helix Iα-loop-helix Iβmotif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recognition.Phe-301,Ser-303 and Gly-305 from the helix Iα-loop-helix Iβmotif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.
文摘The latest results from our research group in the biotransformation of triptolides and bufadienolides were reviewed. The trends in the development of biotransformation in the future were also briefly discussed.
文摘<Abstrcat> The contents of lignans glycosides in five species of \%Gaultheria \%Kalm ex L. were measured by HPLC. The resultes proved that 5 plants collected from same place all contain lignans glycosides (LD). The contents of LD in the roots of different plants shows: \%G. fragrantissima>G. leucocarpa \%var. \%yunnanensis>G. leucocarpa \%var. \%cumingiana>G. tetramera>G. griffithiana, \%and these of the above\|ground parts indicate \%G. fragrantissima>G. leucocarpa \%var. \%yunnanensis\%. The contents of LD in the leaves of \%G. fragrantissima \%and \%G. leucocarpa \%var. \%cumingiana \%are higher than those in the stems, and that in stem of \%G. griffithiana \%higher than that in its leaf and root.
