(2S)-2-Amino-5-chloro-4-hydroxy-5-hexenoic acid,a new chloroamino acid,and related compounds fromAmanita gymnopus

Combining different chromatography systems, unusual nonprotein amino acids were isolated and unequivocally identified from a small amount (less than 100 g fresh weight) ofAmanita gymnopus fruit body. Without obtaining crystals of these amino acids, on the basis of¹H-NMR determination, high resolution mass spectrometry, chlorine analysis and oxidation with L-amino acid oxidase, one of them proved to be a new chloroamino acid, (2S)-2-amino-5-chloro-4-hydroxy-5-hexenoic acid (G2). The other three were (2S)-2-amino-5-hexenoic acid (G1), (2S)-2-amino-4,5-hexadienoic acid (G3) and (2S)-2-amino-5-hexynoic acid (G4). Amino acid (G1) was also encountered for the first time in natural products. Amino acid (G3) has been reported from several kinds of fungi belonging toAmanita, subgenusLepidella. The occurrence of amino acid (G4) was already reported fromCortinarius claricolor.Part 23 in the series Biochemical studies of nitrogen compounds in fungi. Part 22, Hatanaka, S. I. et al. 1985. Trans. Mycol. Soc. Japan26: 61–68.     

渍水对冬小麦生长的危害及其生理效应

小麦受渍后叶片的光合和蒸腾速率迅速下降,而后则显微弱的回升趋势。渍害不仅削弱小麦光合产物的积累,并且改变光合产物在地上部分和根系中的分配比例;植株根／冠比下降,而黄叶的发展与根／冠比的变化呈显著负相关;渍害改变小麦的发育进程,尤其是后期渍害明显促使小麦早衰。认为清水使叶片光合速率降低、光合有效面积损失和衰老加速,从而危害小麦的生长。     

人结肠癌(CCA)单克隆抗体及其识别抗原的分析(简报)

正常细胞转化成癌细胞后,其表型发生了一系列不同于正常细胞的变化,成为肿瘤细胞的标志。Gold和Freeman(1965)用人结肠癌组织的抽提物免疫兔,发现有些用人正常结肠组织吸收后的抗血清能够与肿瘤组织和胚胎肠道抽提物起反应,但不与正常组织抽提物起反应,由于这种抗原最初被发现在胚胎组织,故名为癌胚抗原(embryonic carcinoma antigen,简称CEA)。用敏感的放射免疫或免疫酶标方     

Logistic曲线参数的一个最佳估计方法

本文提出用O．628优选法和SAS/STAT软件NLIN模块中的DUD法,对Logistic曲线中的参数k,a和b可得到最佳估计。     

发酵活性豆渣饲料的研究

活性豆渣饲料是新鲜豆渣经微生物发酵而得到的。本文介绍了发酵菌株的筛选过程,并对发酵的最适条件进行了研究。分析结果表明,这种饲料含有蛋白酶等多种酶类,蛋白质、氨基酸的含量均比未发酵的豆渣有所增加,而且克服了豆渣含水量大、易腐败的缺点,有利于畜禽更充分地消化吸收。经动物喂养实验证明．活性豆渣饲料可代替５０％以上的鱼粉,是一种非常理想的蛋白饲料。     

地高辛标记反意RNA探针检测脑组织切片生长抑素mRNA

本实验采用含大鼠生长抑素基因的ｐＳＰ６５ｃＤＮＡ质位通过转化至噬菌体内大量扩增,经提取,纯化后,用限制性内切酶进行酶切使质枝线性化,并将其作为模板,用地高辛（ＤｉｇｏｘｉｇｅｎｉｎＤｉｇ）作为标记物,体外转录合成生长抑素反意ＲＮＡ（ｃＲＮＡ）探针。实验动物选用ｗｉｓｔａｒ新生大鼠。冰冻切片,端、间脑切片经杂交前用Ｄｉｇ－ＵＴＰ标记的ｃＲＮＡ探针杂交,杂交后用抗Ｄｉｇ－碱性磷酸酶复合物进行酶联免疫反应。Ｘ－磷酸盐－ＮＢＴ显色。结果显示新生大鼠脑内生长抑素ｍＲＮＡ神经元着紫蓝色。杂交反应物集中于核周的胞浆及短小的突起内。胞核不着色。胞体轮廓清晰,周围背底浅淡。结果表明Ｄｉｇ标记ｃＲＮＡ探针不仅具备非同位素标记探针的优点而且能快速和准确检测组织细胞内ｍＲＮＡ的表达。     

钙／钙调素依赖性蛋白激酶对17．7kD和6kD胰腺蛋白的磷酸化

本文报导了胰腺提取物中两种可被钙／钙调素依赖性蛋白激酶磷酸化的热稳定蛋白。ＳＤＳ－ＰＡＧＥ测定其表观分子量分别为１７．７ｋＤ和６ｋＤ。经钙／钙调素依赖性蛋白激酶磷酸化后,其最大磷酸参入量为８．８μｍｏｌ／ｇ蛋白。同时磷酸化作用导致１７．７ｋＤ蛋白在ＳＤＳ－ＰＡＧＥ中迁移率发生变化。本文还进一步分析了各种阳离子对磷酸化的影响,并对此两种蛋白可能具有的生理功能进行了初步探讨。     

The giant panda is closer to a bear,judged by α- and β-hemoglobin sequences

Summary Using - and -hemoglobin sequences, we made a maximum likelihood inference as to the phylogenetic relationship among carnivores, including the two pandas, giant and lesser. Molecular phylogenetic studies up to 1985 had consistently indicated that the giant panda is more closely related to the bear than to the lesser panda. In 1986, however, a contradictory tree was constructed, using hemoglobins and so on, in which the two pandas link together (Tagle et al. 1986). In contrast to that tree, our conclusion supports the close relationship between bear and giant panda. The surface impression of a close relationship between the two pandas drawn from pairwise amino acid differences is explained by a rapid rate of hemoglobin evolution in the bear compared to that in the two pandas.Offprint requests to: T. Hashimoto     

Isolation and characterization of axolemma-enriched fractions from rabbit and bovine peripheral nerve

Axolemma-enriched fractions were isolated from bovine spinal accessory nerves, bovine intradural dorsal roots, and rabbit sciatic nerve by differential centrifugation and separation on a linear 10–40% sucrose (w/w) gradient. The fractions were enriched 4 to 10 fold in acetylcholinesterase, a biochemical marker for axolemma. Axolemma-enriched fractions isolated from uniformly well-myelinated fibers (bovine spinal accessory nerve) contained lower CNPase activity and higher acetylcholinesterase activity than comparable fractions isolated from variably myelinated fibers (rabbit sciatic nerve and bovine intradural roots). Separation by polyacrylamide electrophoresis showed that the molecular weight distribution of all peripheral nerve axolemma-enriched fractions was similar and ranged from 20 to over 150 kilodaltons. All axolemma-enriched fractions appeared to contain a small but variable amount of myelin-specific proteins. Based on biochemical properties, peripheral nerves containing uniformly well-myelinated fibers yield an axolemma-enriched fraction which is least contaminated with myelin-related membranes.