From the ethanolic extract of the whole plant of Hemistepta lyrata Bunge., a new lignan, named hemislin B glucoside, has been isolated and identified as a-(trans-3-methoxy-4-O-b-D-glucopyranosylbenzylidene)-b-(3,4-dim...From the ethanolic extract of the whole plant of Hemistepta lyrata Bunge., a new lignan, named hemislin B glucoside, has been isolated and identified as a-(trans-3-methoxy-4-O-b-D-glucopyranosylbenzylidene)-b-(3,4-dimethoxybenzyl)-g-butyrolactone. Its structure has been established on the basis of UV, IR, FABMS, 1H-NMR, 13C-NMR, HMQC and HMBC spectral analysis.展开更多
ENOX (ECTO-NOX) proteins are proteins of the external surface of the plasma membrane that catalyze oxidation of both NADH and hydroquinones as well as carry out protein disulfidethiol interchange. They exhibit both pr...ENOX (ECTO-NOX) proteins are proteins of the external surface of the plasma membrane that catalyze oxidation of both NADH and hydroquinones as well as carry out protein disulfidethiol interchange. They exhibit both prion-like and time-keeping (clock) properties. The oxidative and interchange activities alternate to generate a regular period of 24 min in length. Here we report the cloning, expression, and characterization of a plant candidate constitutive ENOX (CNOX or ENOX1) protein from Arabidopsis lyrata. The gene encoding the 335 (165) amino acid protein is found in accession XP-002882467. Functional motifs characteristics of ENOX proteins previously identified by site-directed mutagenesis and present in the candidate ENOX1 protein from plants include adenine nucleotide and copper binding motifs along with essential cysteines. However, the drug binding motif (EEMTE) sequence of human ENOX2 is absent. The activities of the recombinant protein expressed in E. coli were unaffected by capsaicin, EGCg, and other ENOX2-inhibiting substances. Periodic oxidative activity was exhibited both with NAD(P)H and reduced coenzyme Q as substrate. Bound copper was necessary for activity and activity was inhibited by the ENOX1-specific inhibitor simalikalactone D. Addition of melatonin phased the 24-min period such that the next complete period began 24 min after the melatonin addition as appeared to be characteristic of ENOX1 activities in general. Periodic protein disulfide-thiol interchange activity also was demonstrated along with the 2 oxidative plus 3 interchange activity pattern characteristics of the 24-min ENOX1 protein period. Concentrated solutions of the purified plant ENOX1 protein formed insoluble aggregates, devoid of enzymatic activity, resembling amyloid. Activity was restored to aggregate preparations by isoelectric focusing.展开更多
在水温28.5-30℃、盐度23.6-25.4条件下，观察了皱肋文蛤（Meretrix lyrata）胚胎、幼虫和稚贝的发育过程。结果表明，皱肋文蛤的胚胎经历桑椹期、囊胚期、原肠胚期等阶段，形成担轮幼虫。根据行为方式和形态特征，其幼虫阶段可分为D形...在水温28.5-30℃、盐度23.6-25.4条件下，观察了皱肋文蛤（Meretrix lyrata）胚胎、幼虫和稚贝的发育过程。结果表明，皱肋文蛤的胚胎经历桑椹期、囊胚期、原肠胚期等阶段，形成担轮幼虫。根据行为方式和形态特征，其幼虫阶段可分为D形幼虫、壳顶初期幼虫、壳顶中期幼虫、壳顶后期幼虫、变态期幼虫、附着期幼虫。稚贝发育可分为无管期稚贝、单管期稚贝和双管期稚贝。皱肋文蛤幼虫在不同阶段的生活习性逐渐改变，从担轮幼虫至壳顶后期幼虫营浮游生活，变态期和附着期幼虫分别营匍匐生活和附着生活。壳顶初期幼虫出现足原基，壳顶中期和壳顶后期幼虫分别形成平衡囊和鳃丝。稚贝阶段开始从附着生活向埋栖生活过渡。稚贝出现明显的次生壳，无管期稚贝和单管期稚贝的次生壳为红褐色，而双管期稚贝的次生壳为白色。皱肋文蛤从 D 形幼虫发育到附着期幼虫，后者的壳长和壳高分别增至前者的1.77倍和2.10倍；稚贝阶段从无管期发育到双管期，后者的壳长和壳高分别增至前者的3.13倍和3.28倍，显示皱肋文蛤幼虫阶段缓慢生长，稚贝阶段快速生长的特征。展开更多
文摘From the ethanolic extract of the whole plant of Hemistepta lyrata Bunge., a new lignan, named hemislin B glucoside, has been isolated and identified as a-(trans-3-methoxy-4-O-b-D-glucopyranosylbenzylidene)-b-(3,4-dimethoxybenzyl)-g-butyrolactone. Its structure has been established on the basis of UV, IR, FABMS, 1H-NMR, 13C-NMR, HMQC and HMBC spectral analysis.
文摘ENOX (ECTO-NOX) proteins are proteins of the external surface of the plasma membrane that catalyze oxidation of both NADH and hydroquinones as well as carry out protein disulfidethiol interchange. They exhibit both prion-like and time-keeping (clock) properties. The oxidative and interchange activities alternate to generate a regular period of 24 min in length. Here we report the cloning, expression, and characterization of a plant candidate constitutive ENOX (CNOX or ENOX1) protein from Arabidopsis lyrata. The gene encoding the 335 (165) amino acid protein is found in accession XP-002882467. Functional motifs characteristics of ENOX proteins previously identified by site-directed mutagenesis and present in the candidate ENOX1 protein from plants include adenine nucleotide and copper binding motifs along with essential cysteines. However, the drug binding motif (EEMTE) sequence of human ENOX2 is absent. The activities of the recombinant protein expressed in E. coli were unaffected by capsaicin, EGCg, and other ENOX2-inhibiting substances. Periodic oxidative activity was exhibited both with NAD(P)H and reduced coenzyme Q as substrate. Bound copper was necessary for activity and activity was inhibited by the ENOX1-specific inhibitor simalikalactone D. Addition of melatonin phased the 24-min period such that the next complete period began 24 min after the melatonin addition as appeared to be characteristic of ENOX1 activities in general. Periodic protein disulfide-thiol interchange activity also was demonstrated along with the 2 oxidative plus 3 interchange activity pattern characteristics of the 24-min ENOX1 protein period. Concentrated solutions of the purified plant ENOX1 protein formed insoluble aggregates, devoid of enzymatic activity, resembling amyloid. Activity was restored to aggregate preparations by isoelectric focusing.
文摘在水温28.5-30℃、盐度23.6-25.4条件下，观察了皱肋文蛤（Meretrix lyrata）胚胎、幼虫和稚贝的发育过程。结果表明，皱肋文蛤的胚胎经历桑椹期、囊胚期、原肠胚期等阶段，形成担轮幼虫。根据行为方式和形态特征，其幼虫阶段可分为D形幼虫、壳顶初期幼虫、壳顶中期幼虫、壳顶后期幼虫、变态期幼虫、附着期幼虫。稚贝发育可分为无管期稚贝、单管期稚贝和双管期稚贝。皱肋文蛤幼虫在不同阶段的生活习性逐渐改变，从担轮幼虫至壳顶后期幼虫营浮游生活，变态期和附着期幼虫分别营匍匐生活和附着生活。壳顶初期幼虫出现足原基，壳顶中期和壳顶后期幼虫分别形成平衡囊和鳃丝。稚贝阶段开始从附着生活向埋栖生活过渡。稚贝出现明显的次生壳，无管期稚贝和单管期稚贝的次生壳为红褐色，而双管期稚贝的次生壳为白色。皱肋文蛤从 D 形幼虫发育到附着期幼虫，后者的壳长和壳高分别增至前者的1.77倍和2.10倍；稚贝阶段从无管期发育到双管期，后者的壳长和壳高分别增至前者的3.13倍和3.28倍，显示皱肋文蛤幼虫阶段缓慢生长，稚贝阶段快速生长的特征。
