人源性基因calsenilin/KChIP3/DREAM的单克隆抗体的制备及鉴定

Calsenilin/KChIP3/DREAM, 是脑中高表达蛋白,最初发现是因其与presenilin 和钙离子结合而得名。作为转录因子抑制因子,该基因在细胞核内具有多种功能。该基因在钙离子作用下细胞核内常常与c-fos、prodynorphin等基因的启动子下游的特异性DRE位点相结合,调节这些基因的表达。另一方面,作为钾离子通道结合蛋白,该基因具有4种isoforms,其中KChIP1广泛存在于各种组织中而KChIP2只在心脏中特异表达,KChIP3和 KChIP4则在脑中显示较高的表达。4种基因在C-端结构非常相象,N-端则显示多样性。除此之外,和许多基因相似,calsenilin经PKC、CKI、PKA等激酶作用可产生多位点的磷酸化,其中主要位点Ser63的磷酸化可以阻止caspase-3对该基因的降解作用。另一方面,Calsenilin作为转录因子激动因子结合于维生素D和视黄酸效应因子启动子上游促进转录的进行。 到目前为止,Calsenilin/KChIP3/DREAM在细胞核内具有双重基因表达调控作用,即当结合于启动子上游时显示正调控而当结合在启动子下游时显示负调控。为了更加深入研究calsenilin的功能及寻找新的受其调控的基因,首先制备可特异性识别的单克隆抗体。利用RT-PCR 技术,从人脑中提取RNA扩增calsenilin全基因,克隆于pGEX-4T-2原核细胞表达载体中,经IPTG诱导表达、Gluthathion Sepharose 4B纯化得到GST-calsenilin/DREAM/KChIP3重组蛋白,并免疫小鼠。通过PEG细胞融合得到单克隆抗体。经细胞免疫染色及Western blotting检测显示说明本实验得到单克隆抗体可以用来进行细胞免疫染色及Western blotting等检测。该抗体的成功制备,为今后对calsenilin/DREAM/KChIP3调控基因表达的更深入研究提供了有效工具,也填补了国内尚无该基因单克隆抗体资源的空白。     

DREAM/Calsenilin/KChIP3:神经系统的多功能蛋白

新近发现的转录因子DREAM(downstreamregulatoryelementantagonistmodulator)可结合到基因(包括PPD、Hrk、cfos等)的DRE(downstreamregulatoryelement)位点,抑制基因转录。它是第一个已知的可以直接与DNA结合发挥转录抑制作用的Ca2 结合蛋白,为Ca2 调节基因表达除蛋白激酶/磷酸酶这条主要通路外提供了另一条通路。由于DREAM与另两个研究小组发现的蛋白calsenilin和KChIP3实为同一种物质,所以DREAM具有PS(presenilin)作用蛋白、Kv4通道调节蛋白和转录因子的多重功能特性。本文将就DREAM的分布、功能及其调控、DREAM与疼痛的关系作简要综述。     

人NPCEDRG基因启动子的克隆及CCAAT/NFY结合位点初步分析

NPCEDRG基因是采用基因定位候选克隆策略获得的一个鼻咽癌候选抑瘤基因.NPCEDRG在鼻咽癌细胞和组织中表达下调,重新恢复NPCEDRG基因在CNE2细胞系的表达,可部分逆转CNE2的恶性表型.为揭示NPCEDRG基因在鼻咽癌细胞和组织中表达下调的分子机制,联合应用生物信息学和报告基因载体系统分析方法对NPCEDRG基因启动子区进行克隆及功能分析,系统发育进化足迹分析结果表明,NPCEDRG基因5′端调控区-180～+235 bp区间在脊椎动物中高度保守,该保守区域中存在包括CCAAT/NFY、STAT1和SP1等转录因子结合位点.构建Luc和/或EGFP报告基因表达载体并检测其启动子活性,-146～-8 bp区域有较强的启动子活性,电泳迁移阻滞分析实验(EMSA)提示,CCAAT/NFY转录因子结合位点是NPCEDRG基因的转录调控元件.因此,研究确定-146～-8 bp区域是NPCEDRG基因核心启动子区域且启动子核心元件CCAAT/NFY可能参与NPCEDRG基因的转录调控.     

GLI3、EN1基因在单纯性马蹄内翻足发生中的功能研究

为了探讨人类GLI3基因在单纯性马蹄内翻足(Idiopathic congenital talipes equinovarus, ICTEV)发生时所起的作用, 文章构建了大鼠Gli3基因启动子区域荧光素酶报告基因表达载体来分析Gli3基因启动子的活性, 并利用P-Match软件预测大鼠Gli3基因启动子区域可能的调控元件, 应用ChIP实验加以验证。并利用RT-PCR、免疫组化和Western blotting的方法分析大鼠En1与ICTEV的相关性。经P-Match软件预测, Gli3基因启动子区域有３个转录因子En1的可能结合位点, 经ChIP实验证实位点1是真正结合位点。RT-PCR、免疫组化和Western blotting方法都证实En1基因在马蹄内翻足模型鼠中表达下降。结果提示大鼠的转录因子 En1可能是Gli3基因的上游负调控元件。在ICTEV患者中, 很可能是由于EN1基因表达水平的下降导致了GLI3基因表达水平的上升, 最终导致ICTEV的发生。     

PC-1增强受体酪氨酸激酶家族成员EphA3在前列腺癌细胞中的转录

为了研究前列腺癌相关基因(prostate and colon gene 1, PC-1）对受体酪氨酸激酶家族分子EphA3表达的影响,用RT-PCR、实时PCR和Western印迹检测表达不同水平PC-1的前列腺癌细胞系LNCaP和C4-2中EphA3的表达情况. 发现PC-1可诱导EphA3基因表达上调. 采用荧光素酶实验检测PC-1对于EphA3启动子转录活性的影响,结果显示,PC-1对转录起始位点上游916 bp的启动子活性没有影响,而可增强转录起始位点上游2011 bp启动子的活性.对EphA3启动子－916 bp～－2　011 bp区域进行生物信息学分析,结果显示,此区域包含HSF、NF-1、Nkx-2、SP1和GATA-1等多种转录因子结合位点.实验结果表明,PC-1可通过影响EphA3启动子诱导EphA3基因高表达,其调控区域位于转录起始位点上游－2　011　bp至－916 bp之间,提示PC-1可能通过影响一些结合于此区域的转录因子来影响EphA3启动子的转录活性.     

老年痴呆症相关基因Nicastrin的转录调控

APP蛋白经过降解,形成老年痴呆症患者脑内老年斑的主要成分.由PS(早老素),NCT,PEN-2和APH-14种膜蛋白组成的γ分泌酶催化该降解过程.为了了解人类nicastrin(NCT)基因的转录调控机制,确定了其在人脑中的转录起始位点以及其编码区上游大小不等片段的转录起始活性.EMSA分析证实NCT启动子区的4个AP-1结合位点和2个NFAT结合位点能够与相应的转录因子结合,能够改变转录因子调控能力的定点突变和PDTC诱导使得NCT启动子在HeLa细胞和人鼠皮质神经元中的启动活性都有所改变.以上结果说明:AP-1和NFAT确实参与了人类NCT基因的转录调控.     

人HAS3启动子的结构与功能初步分析

透明质酸合酶3（hyaluronan synthase 3,HAS3）,是一个参与透明质酸合成的酶分子,在上皮形成和肿瘤转移等过程中起重要作用.为了进一步研究HAS3基因的转录调控机制,本研究克隆鉴定了HAS3基因的启动子.首先应用5′RACE（rapid amplification of cDNA ends,cDNA末端快速扩增）技术鉴定了HAS3基因的转录起始位点,发现了丰度和转录起始位点不同的两种新的HAS3基因剪接变异体.通过PCR定向克隆策略,构建了覆盖HAS3基因5′端侧翼区起始密码子ATG上游约4.3 kb区域的一系列HAS3基因启动子荧光素酶报告基因重组体.启动子活性分析表明,HAS3基因启动子定位于转录起始位点附近约450 bp的区域内.转录因子结合位点分析表明,HAS3基因启动子缺乏典型的TATA盒,但含有典型的GC盒以及C/EBP等其它潜在的转录因子结合位点. 结果提示,Sp1和C/EBP等转录因子可能参与HAS3基因的转录调控.     

一个功能丰富的转录调控分子——下游调控元件拮抗分子

下游调控元件拮抗分子(downstream regulatory element antagonist modulator,DREAM)与钙衰蛋白(Calsenilin)和钾通道辅助亚基(potassium channel interacting protein 3,KCh IP3),三者同属于神经钙感受器蛋白(neuronal calcium sensor,NCS)家族,由同一基因编码,但亚细胞定位不同且执行不同功能,其中DREAM定位于细胞核,有4个EF手型结构域(EF-hand-like motifs)能与钙离子可逆结合,诱导蛋白空间结构变化,结合到多种基因的下游调控元件(downstream regulatory element,DRE)位点发挥基因转录调节作用。DREAM在中枢神经系统(central nervous system,CNS)尤其是小脑皮层中高表达,通过调控N-甲基-D-天冬氨酸受体(N-methyl-D-aspartic acid receptor,NMDAR)影响学习和记忆,也参与阿尔兹海默症发病、炎症反应、血栓形成。随着更多DREAM新功能的发现,其在CNS中的生物功能受到更多关注。本文回顾DREAM的发现历史,分析该蛋白的结构功能特点、组织分布,讨论了近些年来在DREAM入核的调控、以及特有的钙依赖的基因调控机理方面研究进展,重点关注了DREAM-强啡肽原(prodynorphin,PDYN)-强啡肽(dynorphin,DYN)通路调节慢性疼痛的可能机制。     

ATP/ADP exchange activity of gastric (H+ + K+)-ATPase

The ATP/ADP exchange is shown to be a partial reaction of the $\text{(}\text{H}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ by the absence of measurable nucleoside diphosphokinase activity and the insensitivity of the reaction to $\text{P}{}^1$, $\text{P}{}^5$ -di(adenosine-5′) pentaphosphate, a myokinase inhibitor. The exchange demonstrates an absolute requirement for Mg²⁺ and is optimal at an ADP/ATP ratio of 2. The high ATP concentration ($\text{K}{}_{0.5}\text{= 116 μ}\text{M}$) required for maximal exchange is interpreted as evidence for the involvement of a low affinity form of nucleotide site. The ATP/ADP exchange is regarded as evidence for an ADP-sensitive form of the phosphoenzyme. In native enzyme, pre-steady state kinetics show that the formation of the phosphoenzyme is partially sensitive to ADP while modification of the enzyme by pretreatment with 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of Mg²⁺ results in a steady-state phosphoenzyme population, a component of which is ADP sensitive. The ATP/ADP exchange reaction can be either stimulated or inhibited by the presence of K⁺ as a function of pH and Mg²⁺.     

A/California/7/2009与A/California/4/2009病毒感染力比较

目的甲型H1N1流感病毒A/California/7/2009与A/California/4/2009病毒序列比较同源性在99%以上,本实验旨在比较两株病毒感染BALB/c小鼠研究感染力强弱。方法分别将A/California/7/2009（CA7）与A/California/4/2009（CA4）两株病毒分别连续10倍稀释后,对4~6周龄雌性BALB/c小鼠经乙醚麻醉后进行滴鼻攻毒,每个稀释度接种10只实验小鼠,测定CA7 MLD50为101.24/0.05 mL,检测小鼠感染、致病的多项指标,观察期为14 d。结果相同TCID50的CA7和CA4病毒感染小鼠,CA4感染小鼠后14 d内死亡率为20%,而CA7感染小鼠后8 d内死亡率为100%。CA7 106TCID50感染的小鼠病理表现为重度弥漫性间质性肺炎,CA4 106TCID50感染的小鼠病理表现为中度-重度间质性肺炎。结论在相同条件下,CA7感染力明显强于CA4。     

AutoFACT: AnAutomaticFunctionalAnnotation andClassificationTool

Background  

Assignment of function to new molecular sequence data is an essential step in genomics projects. The usual process involves similarity searches of a given sequence against one or more databases, an arduous process for large datasets.     

Comparison of parameters estimated from A/Ci and A/Cc curve analysis

The parameters estimated from traditional A/C _i curve analysis are dependent upon some underlying assumptions that substomatal CO₂ concentration (C _i) equals the chloroplast CO₂ concentration (C _c) and the C _i value at which the A/C _i curve switches between Rubisco- and electron transport-limited portions of the curve (C _i-t) is set to a constant. However, the assumptions reduced the accuracy of parameter estimation significantly without taking the influence of C _i-t value and mesophyll conductance (g _m) on parameters into account. Based on the analysis of Larix gmelinii’s A/C _i curves, it showed the C _i-t value varied significantly, ranging from 24 Pa to 72 Pa and averaging 38 Pa. t-test demonstrated there were significant differences in parameters respectively estimated from A/C _i and A/C _c curve analysis (p<0.01). Compared with the maximum ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (V_cmax), the maximum electron transport rate (J_max) and J_max/V_cmax estimated from A/C _c curve analysis which considers the effects of g _m limit and simultaneously fits parameters with the whole A/C _c curve, mean V_cmax estimated from A/C _i curve analysis (V_cmax-C _i) was underestimated by 37.49%; mean Jmax estimated from A/C _i curve analysis (J_max-C _i) was overestimated by 17.8% and (J_max-C _i)/(V_cmax-C _i) was overestimated by 24.2%. However, there was a significant linear relationship between V_cmax estimated from A/C _i curve analysis and V_cmax estimated from A/C _c curve analysis, so was it J_max (p<0.05).     

Characterization of cytochrome P-450SCC-containing liposomes

Purified cytochrome $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ from bovine adrenocortical mitochondria was incorporated into liposomes by the cholate-dilution method utilizing either dialysis or Sephadex gel filtration. Among synthetic phospholipids tested, dioleoylglycerophosphocholine showed the best stability during the incorporation of $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ into liposomes. A maximum amount of heme was incorporated into liposomes at a molar ratio of phospholipid to the cytochrome of approx. 200. When $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was incorporated into the dioleoylglycerophosphocholine liposomes by the cholate-filtration method, the $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}\text{-}\text{containing liposomes}$ showed two major populations on the elution pattern of the Sepharose 4B gel filtration, and were seen at a diameter of 200–600 Å and its aggregated forms. When the cytochrome was incorporated into dioleoylglycerophosphocholine liposomes or cholesterol-free adrenocortical mitochondrial liposomes, $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was less stable than $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ in aqueous solution. Cholesterol or adrenodoxin markedly stabilized the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. Liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ required cholesterol for its optimum reduction with adrenodoxin, adrenodoxin reductase, and NADPH in the presence of CO. About 70% of the total heme in the dioleoylglycerophosphocholine liposomes was reduced by the enzymatic reduction in the presence of cholesterol, indicating that 70% of the total molecules are exposed to the surface of the outer monolayer. In order to see the location of the heme in membrane, the dioleoylglycerophosphocholine-liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was subjected to $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ treatment. This reagent destroyed the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. These results suggest that the heme is located in the proximity of the $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ reacting sites which are exposed to the surface, or located on the vincinity of polar heads of the membrane.     

Ligand-dependent reactivity of (Na+ + K+)-ATPase with showdomycin

Showdomycin inhibited pig brain ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na⁺, K⁺, Mg²⁺ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1)$\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$, (2) $\text{Mg}{}^{\mathrm{2+}}$, $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}$ and none, (3) $\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{,}\text{Na}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}$ and $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}$, (4) $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}\text{,}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}$ and $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}\text{, (5)}\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$ and ATP. The highest rate was obtained in the presence of Na⁺, Mg²⁺ and ATP. The apparent concentrations of Na⁺, Mg²⁺ and ATP for half-maximum stimulation of inhibition ($\text{K}{}_{0.5}{}^{\mathrm{<mtext>s</mtext>}}$) were 3 mM, 0.13 mM and 4μM, respectively. The rate was unchanged upon further increase in Na⁺ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E₁, E₂, ES, E₁-P and E₂-P, i.e., E₂ has higher reactivity with showdomycin than E₁, while E₂-P has almost the same reactivity as E₁-P. We conclude that the reaction of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ proceeds via at least four kinds of enzyme form (E₁, E₂, E₁ · nucleotide and EP), which all have different conformations.     

Characterization of partially purified (Na+ + K+)-ATPase from porcine lens

The partial purification of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from pig lens has been achieved by treatment with deoxycholate followed by density gradient centrifugation. The specific activity of the final preparation, ranging from 300 to 500 nmol/h per mg protein, is increased approx. 100-fold compared to the homogenate. A parallel increase in $\text{p-}\text{nitrophenylphosphatase}$ activity is also observed. Sodium dodecyl sulfate (SDS) gel electrophoresis reveals six major protein bands, one of which is the 93 kDa α subunit of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ which can be phosphorylated by reaction with [γ-³²P]ATP. A second band contains a glycoprotein which displays an apparent molecular weight of 51 000 and thus appears to be the β subunit of the enzyme. The enzyme is sensitive to ouabain with the $\text{I}{}_{50}$ for $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ and $\text{p-}\text{nitrophenylphosphatase}$ inhibition being 1.2 and 1.3 μM, respectively. Several agents which inhibit $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from other tissues such as oligomycin, Ca²⁺, vanadate, $\text{N-}\text{ethylmaleimide}$, $\text{p-}\text{chloromercuribenzenesulfonic acid}$ (PCMBS) and 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) also inhibit the lens enzyme. Monovalent cations other than K⁺ are partially effective in activating the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}$)-ATPase and $\text{p-}\text{nitrophenylphosphatase}$ activities. The K⁺ congeners were relatively more effective in supporting $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ compared to $\text{p-}\text{nitrophenylphosphatase}$ activity. Other kinetic properties of the lens enzyme are also comparable to those of the enzyme from other tissues. Utilizing the partially purified membrane bound enzyme, discontinuities in Arrhenius plots of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity, $\text{p-}\text{nitrophenylphosphatase}$ activity and fluoresence polarization of the fluidity probe, 1,6-diphenyl-1,3,5-hexatriene (DPH), are observed near the physiological temperature of lens. The possible significance of these observations for the mechanism of cataract formation are discussed.     

An electron spin probe study of (Na+ + K+)-ATPase-Containing membranes

The modulating effect of membrane lipids on enzyme function has been described by several investigators. We have used the spin probe $\text{N-}\text{oxyl}\text{-4′,4′-}\text{dimethyloxazolidine}\text{-12-}\text{keto}$ methyl stearate (M 12-NSE) to study this interaction in ox brain membranes enriched with $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$. This methyl ester of stearic acid is practically insoluble in aqueous media, and consequently spectra of M 12-NSE-labelled preparations are free of “liquid lines”.At least two types of spectra may be obtained when ox brain microsomes are spin labelled with M 12-NSE, indicating the presence of two distinct binding sites. At one site the spin label is relatively unrestricted and gives rise to an isotropic spectrum. A second spectrum, which is obtained from spin label at another site, is similar to that which is observed after incorporation of M 12-NSE into phospholipid bilayers. This suggests that this latter site is within the core of the microsomal membrane.The two binding sites differ in their affinity for the spin probe. The low affinity site is both more abundant in crude preparations and is more easily removed by detergent treatment; spin labels at this site produce isotropic spectra. The high affinity sites are fewer in number and produce broad spectra. In addition these high affinity sites increase in concentration as the enzyme undergoes purification.The two sites are quite distinct in their sensitivity to ascorbic acid, the low affinity site showing a considerably greater rate of reduction by this agent.This study also demonstrates that the delipidation effects of sodium dodecyl sulfate and sodium deoxycholate on $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase-enriched}$ microsomes from ox brain are not identical.It is suggested that the two spin probe binding sites represent two different lipid domains, one of which is very closely associated with the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme and may reflect a protein-directed phospholipid specificity for this enzyme.     

Occurrence of N-malonyl-D-alanine in pea seedlings

One of the ninhydrin-negative alanine conjugates isolated from pea seedlings was identified as $\text{N-}\text{malonyl}\text{-}\text{D}\text{-}\text{alanine}$.The identification of this conjugate was carried out by a comparison of its gas-liquid chromatographic and mass spectrometric properties, and its nuclear magnetic resonance and infrared spectra with those of synthetic $\text{N-}\text{malonyl}\text{-}\text{D}\text{-}\text{alanine}$. The alanine in the conjugate was shown to be present as the D-isomer by enzymatic and chromatographic analyses.     

catmap: Case-control And TDT Meta-Analysis Package

Background  

Risk for complex disease is thought to be controlled by multiple genetic risk factors, each with small individual effects. Meta-analyses of several independent studies may be helpful to increase the ability to detect association when effect sizes are modest. Although many software options are available for meta-analysis of genetic case-control data, no currently available software implements the method described by Kazeem and Farrall (2005), which combines data from independent family-based and case-control studies.