Investigations of interaction mechanism and conformational variation of serum albumin affected by artemisinin and dihydroartemisinin

In this work, binding interactions of artemisinin (ART) and dihydroartemisinin (DHA) with human serum albumin (HSA) and bovine serum albumin (BSA) were investigated thoroughly to illustrate the conformational variation of serum albumin. Experimental results indicated that ART and DHA bound strongly with the site I of serum albumins via hydrogen bond (H-bond) and van der Waals force and subsequently statically quenched the intrinsic fluorescence of serum albumins through concentration-dependent manner. The quenching abilities of two drugs on the intrinsic fluorescence of HSA were much higher than the quenching abilities of two drugs on the intrinsic fluorescence of BSA. Both ART and DHA, especially DHA, caused the conformational variation of serum albumins and reduced the α-helix structure content of serum albumins. DHA with hydrophilic hydroxyl group bound with HSA more strongly, suggesting the important roles of the chemical polarity and the hydrophilicity during the binding interactions of two drugs with serum albumins. These results reveal the molecular understanding of binding interactions between ART derivatives and serum albumins, providing vital information for the future application of ART derivatives in biological and clinical areas.     

Al-(L-丙氨酸)胰岛素晶体学研究

应用微量过饱和静置法在含柠檬酸钠和氯化钠的晶体生长体系中得到适合Ｘ射线衍射分析用的Ａｌ－（Ｌ－丙氯酸）胰岛素单晶体。晶体属于三方晶系,空间群为Ｒ３晶体衍射分辨率可达１．８Ａ以上。晶胞参数：ａＨ＝８０．８９Ａ,ｂＨ＝８０．８９Ａ,ｃＨ＝３７＼６４Ａ,α＝β＝９０°,γ＝１２０°。每个结晶学不对称单位含有两个Ａｌ－（Ｌ－丙氨酸）胰岛素分子。     

<i>VvAGAMOUS</i> Affect Development of Four Different Grape Species Ovary

Grape pistil has an important influence on fruit size and quality. However, there were few studies on grape ovary, and the development process of the ovary is still unclear. Therefore, in this paper, four different grape varieties with different lengths of small inflorescences, namely ‘Musct Hambourg’ grape (Vitis vinifera), ‘Concord’ grape (Vitis labrusca), ‘ShanPuTao’ grape (Vitis amurensis) and ‘GongNiang2Hao’ grape (Vitis amurensis × Vitis vinifera) were used as test materials. Four varieties ovary were significant differences by means of stereomicroscope, paraffin section. The expression of ovary determining gene VvAGAMOUS (VvAG) and its development related genes VvCRABS CLAW (VvCRC) andVvAGAMOUS-LIKE 11 (VvAGL11) with similar functions during the development of different grape varieties were preliminarily explored using fluorescence quantitative test. The relationship between VvAG and VvCRC, VvAG and VvAGL11 were analyzed using Y1H assay. Our results showed that there were obvious abdominal sutures on the surface of expect for ‘Musct Hambourg’ grape, and existing poly carpels. The ovary development of ‘ShanPuTao’ and ‘GongNiang2Hao’ grape was completed when the inflorescence length was less than 1 cm, while the ‘Concord’ and ‘Musct Hambourg’ grape were fully developed when the length of inflorescence was 3–4 and 4–5 cm, respectively. VvAG and VvCRC began to express in large quantities after the formation of stamen primordia, while VvAGL11 during the forming of ovule primordia. Therefore, VvAG and VvCRC mainly regulated the development of stamens and carpels and also promote the development of ovules, while VvAGL11 major regulated the development of ovules. The promoters of VvCRC and VvAGL11 were bound by VvAG. This study provides an important theoretical basis for further research on the molecular mechanism of grape ovary development.     

Influence of the route of administration on the pharmacokinetics of pirprofen enantiomers in the rat

The pharmacokinetics of the enantiomers of the non-steroidal anti-inflammatory drug pirprofen were studied in male Sprague-Dawley rats after oral and intravenous (iv) doses of the racemate. No significant differences were detected between the enantiomers after oral or iv dosing in t_½, Vd, or ∑Xu. However, the R:S area under the plasma concentration (AUC) ratio after oral doses (0.92 ± 0.13) was slightly but significantly lower than after matching iv doses (1.05 ± 0.036). The absolute bioavailability of the active S-enantiomer (78.5%) after oral doses was higher than the inactive R-enantiomer (69.3%). The plasma protein binding of both enantiomers was saturable over a fivefold range of plasma concentrations. At higher plasma concentrations, the S-enantiomer was less bound than the R-enantiomer. In an in vitro experiment using everted rat jejunum, no chiral inversion was discernible. The dependency of the AUC ratio of the enantiomers on the route of administration may be due to stereoselective first-pass metabolism. © 1993 Wiley-Liss, Inc.     

Subcellular Distribution and Chemical Forms of Cadmium in the Medicine Food Homology Plant <i>Platycodon grandiflorum</i> (Jacq.) A.DC.

Although Platycodon grandiflorum (Jacq.) A.DC. is a renowned medicine food homology plant, reports of excessive cadmium (Cd) levels are common, which affects its safety for clinical use and food consumption. To enable its Cd levels to be regulated or reduced, it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant, in addition to its detoxification mechanisms. This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P. grandiflorum. The experimental results showed that Cd was mainly accumulated in the roots [predominantly in the cell wall (50.96%–61.42%)], and it was found primarily in hypomobile and hypotoxic forms. The proportion of Cd in the soluble fraction increased after Cd exposure, and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves, with a higher increase in oxalate Cd. Therefore, it is likely that root retention mechanisms, cell wall deposition, vacuole sequestration, and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P. grandiflorum. The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P. grandiflorum, and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants.     

Reduced Application of Nitrogen Fertilizer Affects the Carbon Metabolism of Leaves and Maintains the Number of Flowers in Coreopsis tinctoria

This study examined the effects of nitrogen (N) fertilizer reduction on the carbon (C) metabolism and yield of Coreopsis tinctoria. A two-year (2020–2021) hydroponic experiment was conducted in accordance with a randomized complete group design with five N levels [0.875 mM Ca(NO₃)₂ (N1), 1.750 mM Ca(NO₃)₂ (N2), 3.500 mM Ca(NO₃)₂ (N3), 7.000 mM Ca(NO₃)₂ (N4), and 14.000 mM Ca(NO₃)₂ (N5)] and three replications. The results showed that low N significantly affected the functional leaf weight, C metabolism, and flower bud (or flower) numbers of C. tinctoria at harvest. Lower-N levels, especially those of the N2 treatment, significantly increased Rubisco, sucrose synthase (SS), sucrose phosphate synthase (SPS), soluble acid invertase (SAI), glucose 6-phosphate dehydrogenase (G6PDH), and 6-phosphogluconate dehydrogenase (6PGDH) activity and maintained the flower number of C. tinctoria. In addition, the balance of carbohydrates (sucrose, starch, glucose, and fructose) and ATP contents was more efficiently maintained under relatively low-N levels. These findings might suggest that reduced application of N fertilizer affects the C metabolism of leaves and maintains the number of flowers in Coreopsis tinctoria. Applying relatively low-N fertilizer levels is also a promising cultivation strategy for C. tinctoria.

     

Interactive Effects of Iron and Photoperiods on Tomato Plant Growth and Fruit Quality

Journal of Plant Growth Regulation - Photoperiod and micronutrient iron (Fe) are critical for plant growth and development. However, the interactive effects of Fe nutrition and photoperiod on...     

暗纹东方鲀耐寒相关基因CIRBP、HMGB1和AFP-Ⅳ的分子特征和对低温胁迫的响应

为了探索暗纹东方鲀(Takifugu obscurus)对低温环境的响应机制,克隆了暗纹东方鲀耐寒相关基因CIRBP、HMGB1和AFP-Ⅳ的cDNA序列,并进行了基因的分子特征和功能分析。组织分布检测显示CIRBP和HMGB1在下丘脑、肝脏和肌肉中具有高表达,而AFP-Ⅳ则主要在肝脏中表达。在受到低温胁迫后, 3种基因在肝脏和下丘脑中的表达呈现不同的变化趋势,其中CIRBP基因在肝脏中于48h表达量显著增加,在下丘脑中于12h和48h有上调表达; HMGB1基因在肝脏中呈现逐渐上升的趋势,于48h达到最大值,而在下丘脑中呈现先上升后下降的趋势,处理后2h达到最大, 2—8h下降,于8h下降至最低,随后恢复至初始水平;肝脏中的AFP-Ⅳ在0—24h无显著变化,在48h上升至最大值。进一步通过大肠杆菌原核表达系统研究了AFP-Ⅳ的抗冻功能,发现AFP-Ⅳ融合蛋白在–80℃下具有抗冻活性,并且抗冻活性随着浓度的增加而提高。研究结果表明3种基因都参与了暗纹东方鲀对低温胁迫的应答过程,为深入探索暗纹东方鲀的耐低温机制奠定了基础。     

儿童最大有氧活动能力的发展特征

本文报告了我国４６３名１０－１９岁儿童青少年的最大有氧活动能力的发展特征。在青春早期,男女童的最大吸氧量绝对值均随年龄增长而增加,男童由１．７５升／分增至３．１０升／分,女童由１．４４升／分增至２．０７升／分,女童增长较少;以后女童即稳定于这一水平,男童仍略有增长。按身高及按最大心率计标的相对值与其有相似的特征。按体重和瘦体重计算的相对值,在男女童都未见随年龄增长的规律。男童ＶＯ２ｍａｘ绝对值及各