Neuronal pp60c-src contains a six-amino acid insertion relative to its non-neuronal counterpart

Neuronal cells express a pp60c-src variant that displays an altered electrophoretic mobility and a different V8 peptide pattern relative to pp60c-src expressed in tissues of non-neuronal origin. To determine whether the neuronal form of pp60c-src is encoded by a brain-specific messenger RNA, a mouse brain complementary DNA (cDNA) library was screened with a chicken c-src probe and a 3.8-kilobase c-src cDNA clone was isolated. This clone encodes a 60-kilodalton protein that differs from chicken or human pp60c-src primarily in having six extra amino acids (Arg-Lys-Val-Asp-Val-Arg) within the NH2-terminal 16 kilodaltons of the molecule. S1 nuclease protection analysis confirmed that brain c-src RNA contains an 18-nucleotide insertion at the position of the extra six amino acids. This insertion occurs at a position that corresponds to a splice junction in the chicken and human c-src genes. The isolated c-src cDNA clone encodes a protein that displays an identical V8 peptide pattern to that observed in pp60c-src isolated from tissues of neuronal origin.     

Blood-brain neutral amino acid transport activity is increased after portacaval anastomosis

In rats after portacaval anastomosis (an animal model of chronic liver disease), transport of tryptophan and other members of the large neutral amino acid group from blood to brain was markedly enhanced. Increased transport activity was apparently restricted to the neutral amino acid transport system, since brain uptake of glucose, inulin, and tyramine was unaffected while blood-brain arginine transport was significantly reduced. These results strikingly confirm the hypothesis that carrier-mediated blood-brain transport is the limiting factor determining the availability of the neutral amino acids to the brain. The encephalopathy associated with cirrhosis may be the result of abnormal neurotransmitter metabolism and neurotransmission secondary to increased neutral amino acid transport activity and an increased brain content of members of the neutral amino acid group.     

桑椹鲜果的营养分析与评价

通过对桑椹鲜果进行测试分析,结果表明:桑椹中含有丰富的营养物质,除了含有水分、蛋白质、氨基酸、维生素、矿物质、糖、酸等基本营养成分外,还含有花青素、白藜芦醇、硒等活性营养成分。尽管这些营养成分对人体的作用机理不同,但它们对人体的健康和保健都具有重要的作用。不同桑椹品种所含的营养成分含量有所不同,氨基酸种类含量较为齐全,其中含有人类所必需的7种氨基酸,游离氨基酸总量为0.65%～1.73%。对几种主要的桑椹品种进行营养成分的检测分析及其功能性评价,可为桑椹的综合利用与深度开发提供参考依据。     

雪山草鸡氨基酸组成与营养价值研究

[目的]评价雪山草鸡的营养价值。[方法]以雪山草鸡为材料,对各种氨基酸的含量及组成进行分析,并评价其营养价值。[结果]雪山草鸡肌肉中氨基酸含量占蛋白质含量的95.34%,且种类齐全,8种人体必需氨基酸的含量达1.096 g/kg。鲜味氨基酸、甜味氨基酸和芳香族类氨基酸占总氨基酸的质量分数分别为24.97%、17.86%和7.07%,各种人体必需氨基酸种类齐全且比例均衡,比值系数分(SRC)为76.91。在各种人体必需氨基酸中,第一限制氨基酸为甲硫氨酸+半胱氨酸。[结论]该研究可为雪山草鸡进一步开发利用提供科学依据。     

人类多囊肾病相关蛋白TMEM130基因的克隆及生物信息学分析

以递交到GenBank上的TMEM130蛋白基因序列(nm-152913)为模板设计引物,以人大脑cDNA文库为模板进行巢氏PCR扩增,并将PCR产物克隆到pMD18-T载体上,成功获得TMEM130蛋白基因编码序列,测序结果显示,获得的序列为TMEM130蛋白基因转录变异体2,其编码序列长1272bp。该基因定位在人类第7条染色体7q22.1区域,有3个转录变异体。生物信息学分析显示该序列可编码1个含423个氨基酸的蛋白质;Smartmode程序显示该蛋白质是1个跨膜蛋白,在100～250号氨基酸序列之间有1个与多囊肾病(PKD)相关的结构域。因此,鉴定TMEM130蛋白是一个与人类多囊肾病相关的蛋白。     

斑马鱼促性腺激素释放激素及相关肽基因的克隆与序列分析

从斑马鱼脑组织提取总RNA,应用RT-PCR方法克隆促性腺激素释放激素(GnRH) cDNA,其长度为646 bp,包括一个258 bp开放阅读框;编码的GnRH前体为86个氨基酸残基,由一个信号肽、GnRH十肽和一个由蛋白水解位点(Gly-Lys-Arg)连接的促性腺激素释放激素相关肽(GAP)组成;其中信号肽和相关肽的长度分别为24和49个氨基酸.该cDNA编码的GnRH的前体氨基酸序列与其他物种的GnRH前体基本一致.表明物种间GnRH cDNA的蛋白编码区高度保守,而非编码区的保守性程度很低.进化分析发现,斑马鱼与鲤、鲫、拟鲤、黑头软口鲦等淡水鲤科鱼类的同源性较高.     

太平洋双色鳗鲡肌肉营养成分分析与评价

测定并分析了太平洋双色鳗鲡(Anguilla bicolor pacifica）肌肉中营养成分组成与质量分数。结果显示院太 平洋双色鳗鲡肌肉中含62.56%、蛋白质15.85%;肌肉中测出氨基酸17 种(未测色氨酸）,总量为36.33%(干样）,其中 包括人体必需氨基酸总量(EAA）7 种,总量为13.99%(干样）,必需氨基酸组成基本符合FAO/WHO 评分标准,太平洋 双色鳗鲡的限制性氨基酸为(蛋氨酸+胱氨酸）和缬氨酸,其必需氨基酸指数(EAAI）为78.26,5 种鲜味氨基酸(DAA） 总量为16.58%(干样）;脂肪酸中单不饱和脂肪酸占44.41%,多不饱和脂肪酸占16.70%,其中EPA+DHA 的占 7.33%。该结果表明,太平洋双色鳗鲡具有较高的使用价值与保健作用。     

不同品种榧树种仁氨基酸组成分析及营养评价

[目的]明确不同品种榧树种仁的氨基酸组分和营养品质。[方法]以6个主栽榧树品种为研究对象,分析种仁不同种类氨基酸组分的含量并进行营养评价。[结果]榧树种仁含有17种常见氨基酸,包含人体必需的7种氨基酸,不同品种的总氨基酸及氨基酸组分含量不同。各品种种仁氨基酸含量从高到低依次为东榧2号、丁山榧、东榧3号、龙凤细榧、东榧1号、朱岩榧;氨基酸组分中天冬氨酸和谷氨酸的含量最高,变异系数较低,人体必需氨基酸(E)与氨基酸(T)的比值为0.39,人体必需氨基酸与非必需氨基酸比值(E/N)为0.64,符合WHO/FAO推荐必需氨基酸组成比例标准;人体必需氨基酸(E)、儿童必需氨基酸(CE)、味觉类氨基酸含量与总氨基酸含量间存在显著正相关关系。[结论]总氨基酸含量可作为氨基酸组分特征的代表性指标对不同品种榧树种仁的营养品质进行评价。     

Stimulation of gonadotropin release by a non-GnRH peptide sequence of the GnRH precursor

The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture. The peptide did not affect thyrotropin or prolactin secretion. A GnRH antagonist did not inhibit gonadotropin stimulation by the peptide, and the peptide did not compete with GnRH for GnRH pituitary receptors, indicating that the action of the peptide is independent of the GnRH receptor. The GnRH precursor contains two distinct peptide sequences capable of stimulating gonadotropin release from human and baboon pituitary cells.     

Molecular Characterization and Expression Pattern of Rheb Gene in Inner Mongolia Cashmere Goat （Capra hircus）

As one member of the Ras super family, Rheb is an upstream regulator of mTOR signaling pathway, which regulates the process of cell-growth, proliferation and differentiation. In order to study the relationship between Rheb and mTOR in Inner Mongolian Cashmere goat (Capra hircus) cells, Ras homolog enriched in brain (Rheb) gene cDNA was amplified by RT-PCR. It is 555 bp in length and includes the complete ORF encoding 184 amino acids (GenBank accession no. HM569224). The full cDNA nucleotide sequence has a 99% identity with that of sheep, 98% with cattle and 93% with human while their amino acids sequence shares identity with 98, 97 and 97% of them, correspondingly. The bio informatics analysis showed that Rheb has a Ras family domain, two casein kinase II phosphorylation sites, two ATP/GTP-binding sites motif A (P-loop), a prenyl group binding site (CAAX box). Tissue-specific expression analysis performed by semi-quantitative RT-PCR. The Rheb gene was expressed in all the tested tissues and the highest level of mRNA accumulation was detected in brain, suggesting that Rheb played an important role in goat cells.     

绿凤藤茶叶片中氨基酸含量及组成分析评价

[目的]评价藤茶营养价值,为藤茶进一步开发和利用提供科学依据。[方法]以藤茶复叶和幼茎为原料,采用氨基酸自动分析仪对样品各种氨基酸的含量进行检测,并对其组成进行比较与分析。[结果]结果表明,藤茶中总氨基酸含量较高,各种人体必需氨基酸种类齐全,且比例均衡,比值系数分(SRC)为77.83。[结论]在藤茶的各种人体必需氨基酸中,第一限制氨基酸为蛋氨酸+胱氨酸。     

两种天牛的营养成分分析

分析了星天牛(Anoplophora chinensis(Forster))和粗鞘双条杉天牛(Semanotus sinoauster Gressit)幼虫的主要营养成分,结果表明:它们的蛋白质为鲜质量的16％～18％,氨基酸分别约为鲜质量的16％和13％,含有7种人体必需氨基酸,其必需氨基酸占氨基酸总质量分数的43％,必需氨基酸与非必需氨基酸的比值为75％-76％,它们的第一限制性氨基酸为含硫氨基酸(蛋氨酸 胱氨酸)。粗脂肪约为鲜质量的13％,其中不饱和脂肪酸所占比例高,约为总脂肪的77％,但它们的必需脂肪酸质量分数差异大,星天牛为30．5％,粗鞘双条杉天牛为2．9％。2种天牛幼虫样品均含有K、Ca、Mg、Fe、Zn、Cu、Mn等多种矿物质和微量元素,胆固醇的质量分数低,平均为0．03％。     

栗山天牛提取物主要营养成分分析与评价

采用现代分析技术对栗山天牛提取物的主要营养成分进行了分析.结果显示：栗山天牛提取物的蛋白质、氨基酸、糖类质量分数分别为37.28%、37.25%、8.61%;含有7种人体必需氨基酸,其必需氨基酸占总氨基酸的40.97%,必需氨基酸与非必需氨基酸的比值为0.6939,第一限制性氨基酸为含硫氨基酸,即蛋氨酸和胱氨酸;还含有Ca、Mg、Fe、Mn、Zn、Cu、Mo、N i、Se、Cr等多种矿物质与微量元素.     

虹鳟PDCD6基因cDNA全长的克隆与功能预测

程序性死亡因子6（PDCD6）基因编码1个含EF-hand结构域的钙离子结合蛋白。应用逆转录PCR及cDNA末端快速扩增（RACE）技术从虹鳟（Oncorhynchus mykiss）脑组织中克隆了PDCD6基因cDNA的全序列（GenBank No：FJ591154）。序列全长1 179bp,其中5’端非翻译区长48bp,3’端非翻译区长567bp,开放性阅读框长564bp,编码187个氨基酸。电子表达谱分析结果表明该基因在4种脊椎动物的多个部位或组织中均有表达。同源模建蛋白三级结构显示该蛋白具有8个主要的α螺旋结构。虹鳟PDCD6蛋白序列与斑马鱼、非洲爪蟾、人、小鼠和鸡的同源性均高于85%,表明PDCD6基因在进化过程中是高度保守的,在细胞程序性死亡过程中发挥重要作用。     

不同品种核桃仁的脂肪酸与氨基酸含量分析

对在山西种植的20个核桃品种核桃仁的脂肪酸和氨基酸组分及含量进行分析研究,结果表明,核桃仁中主要含有棕榈酸、油酸、硬脂酸、亚油酸和α-亚麻酸5种脂肪酸,含量依次为:亚油酸>油酸>α-亚麻酸>棕榈酸>硬脂酸,其中不饱和脂肪酸达到90%左右;亚油酸(ω-6)/α-亚麻酸(ω-3)基本符合联合国粮农组织提出的人类膳食中(ω-6)(/ω-3)的推荐值(5～10)∶1;不同品种脂肪酸组成无差异、含量有差异。20个品种均含有17种氨基酸,其中包括人体必需氨基酸7种;氨基酸种类相同,总体含量有差异。     

烟夜蛾滞育激素的cDNA克隆和序列测定

运用RT -PCR法克隆了烟夜蛾 (HelicoverpaassultaGuen啨ｅ)滞育激素的cDNA ,并对其进行了序列分析 .结果表明 ,烟夜蛾滞育激素由 2 4个氨基酸组成 ,属于FXPRL神经肽家族 ,与家蚕 (BombyxmoriLinnaeus)、棉铃虫 (HelicoverpaarmigeraH櫣ｂｎｅｒ)滞育激素氨基酸序列相比较 ,其同源性分别为 6 2 %和 99% .在烟夜蛾非滞育蛹内未克隆到该滞育激素的cDNA     

10个杨梅品种果实糖和氨基酸含量分析

为了探讨不同杨梅品种果实的风味和营养品质的差异,测定了10个杨梅品种果实的糖及氨基酸含量。结果表明:杨梅果实中的总糖含量为7.1%~10.8%,蔗糖含量为3.6%~6.8%,还原糖含量为2.2%~4.3%。10个杨梅品种果实均含有本研究测定的17种氨基酸,包括Phe、Thr、Lys等7种人体必需氨基酸,His和Arg2种半必需氨基酸。10个杨梅品种果实中氨基酸总量为354.35~701.85 mg/100 g,含量最高的品种是硬丝安海变,含量最低的品种是二色杨梅,不同杨梅品种的必需氨基酸含量和味觉类氨基酸含量也存在较大差异。     

松江鲈肌肉营养成分测定及营养价值评价

[目的]为松江鲈鱼的人工养殖和产品开发提供基础研究数据。[方法]用秦皇岛渤海湾的野生松江鲈鱼为试验样品,对其肌肉的一般营养成分、脂肪酸和氨基酸组成进行测定,并对其营养价值进行评价。[结果]松江鲈的蛋白质含量为17.72%,脂肪含量为1.24%,灰分含量为1.22%。肌肉中不饱和脂肪酸含量占脂肪酸总量的52.2%,含丰富的EPA和DHA,EPA＋DHA占脂肪酸总量的23.2%。鱼肉中含17种氨基酸（色氨酸被水解未测出）,其中含8种必需氨基酸,必需氧基酸含量占氨基酸总量的49.21%,鲜味氨基酸占氨基酸总量的39.72%,氨基酸指数77.18。根据AAS和CS,松江鲈的第1限制氨基酸为蛋氨酸＋半胱氨酸,第2限制氨基酸为缬氨酸。[结论]与其他淡水鱼类相比,松江鲈鱼肌肉蛋白质和氨基酸含量较高,氨基酸组成合理,富含不饱和脂肪酸,有较高的营养价值,是一种非常值得开发利用的淡水鱼类资源。     

Molecular cloning of the complementary DNA for human tumor necrosis factor

Tumor necrosis factor (TNF) is a soluble protein that causes damage to tumor cells but has no effect on normal cells. Human TNF was purified to apparent homogeneity as a 17.3-kilodalton protein from HL-60 leukemia cells and showed cytotoxic and cytostatic activities against various human tumor cell lines. The amino acid sequence was determined for the amino terminal end of the purified protein, and oligodeoxyribonucleotide probes were synthesized on the basis of this sequence. Complementary DNA (cDNA) encoding human TNF was cloned from induced HL-60 messenger RNA and was confirmed by hybrid-selection assay, direct expression in COS-7 cells, and nucleotide sequence analysis. The human TNF cDNA is 1585 base pairs in length and encodes a protein of 233 amino acids. The mature protein begins at residue 77, leaving a long leader sequence of 76 amino acids. Expression of high levels of human TNF in Escherichia coli was accomplished under control of the bacteriophage lambda PL promoter and gene N ribosome binding site.