Effects of temperature on the expression of STN7 and phosphorylation of LHCII proteins in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

In Arabidopsis thaliana, STN7 kinase is required for phosphorylation of LHCII and for state transitions. In this paper, a hydrophilic polypeptide, derived from the amino acid sequence of STN7, was conjugated to a carrier protein, bovine serum albumin （BSA）, to obtain the polyclonal antibody. Immunogenicity and specificity of the polyclonal antibody were evaluated by agar gel immunodiffusion （AGID） test and Western blot analysis. The results show that besides the phosphorylation of LHCII proteins, also the expression of STN7 was regulated by temperature conditions. In addition, the change tendency of LHCII proteins phosphorylation was not only coherent with expression of STN7 with respect to increasing temperature, but also closely related to state transitions. These results would provide useful information for studying regulatory mechanism of LHCII proteins phosphorylation and expression of STN7.     

少棘蜈蚣钠通道毒素NTX-Ssm97的表达、纯化和鉴定

以同源序列比对法从湖北少棘蜈蚣毒腺转录组数据库中筛选到了一个新的毒素多肽基因NTX-Ssm97,其序列与Nav1.7抑制性多肽μ-SLPTX-Ssm6a高度同源.采用基因工程技术,构建了pGEX-4T-1-NTX-Ssm97原核表达载体,并利用E.coli Rosetta对毒素成熟肽的原核诱导表达和分离纯化.MALDI-TOF-MS质谱鉴定结果显示:纯化的NTX-Ssm97分子量与理论值基本吻合,表明少棘蜈蚣转录组数据库有助于筛选靶向Nav1.7钠通道的抑制性毒素多肽基因.     

磷酸化处理对蚕蛹多肽结合钙能力的影响

为探索磷酸化处理对多肽结合钙能力的促进作用,以蚕蛹多肽为研究对象,采用不同种类和添加量的磷酸化试剂对其进行磷酸化改性,再与CaCl₂反应制备蚕蛹多肽结合钙复合物,并对样品进行钙和磷含量测定、磷酸化位点检测、红外光谱分析和扫描电镜分析。研究结果表明:Na₃PO₄、NaH₂PO4、(NaPO₃)₆ 3种试剂可与蚕蛹多肽发生磷酸化反应,改性后蚕蛹多肽结合钙含量可从145.12mg/g提高至202.32mg/g ;不同种类磷酸化试剂处理对多肽的结合钙能力无显著性差异,但磷酸化程度对肽结合钙能力有较大影响;多肽结合钙复合物中钙含量随磷酸化试剂的增加先升高后下降,当采用质量分数为0.50%的NaH₂PO₄时,改性后蚕蛹多肽结合钙含量达到最大值。红外光谱和磷酸化位点检测表明:NaH₂PO₄处理可使蚕蛹酶解产物中的17种肽段被磷酸化,增加磷酸化位点22个;肽段主要通过与丝氨酸和苏氨酸上的—OH反应接入磷酸基团。研究表明,磷酸化改性方法可显著提高多肽结合钙能力,希望为高效的补钙制品开发提供新的思路和方法。     

亚铁血红素肽复合型保护剂的性能

酶解牛血制取亚铁血红素肽,并于酶解底物及产物中分别添加不同种类亚铁保护剂,考察其对产物亚铁血红素肽的保护效果。结果表明,复合型保护剂的性能明显优于单一型。与空白组相比,酶解底物添加2∶1(抗氧化剂/还原剂质量比)的复合型保护剂可使亚铁含量提高24.5%;酶解产物中添加复合型保护剂后(2∶1),亚铁含量可提高37.7%。     

蚕蛹蛋白的开发进展

简要介绍了蚕蛹蛋白质的提取工艺和精制技术,重点介绍了用蚕蛹蛋白资源开发氨基酸、多肽和蚕蛹蛋白纤维的研究进展,并进行了评价.     

大鼠肿瘤腹水中的细胞生长抑制因子

大鼠接种Walker 256肿瘤腹水中存在着细胞生长抑制因子,经纯化为一组多肽类因子。其中5个因子在SDS-PAGE和HPLC上检测为均一的分子,分子量均为5000～6000;4个因子在微晶纤维素膜电泳时呈现单一斑点。采用~3H—胸腺嘧啶核苷掺入法测定,发现细胞生长抑制因子对小鼠艾氏肿瘤细胞、骨髓细胞和大鼠骨髓细胞具有不同的抑制作用。根据细胞抑制专一性的不同,细胞生长抑制因子可分为三类:(1)专一抑制异种细胞;(2)专一抑制正常细胞;(3)对检测靶细胞均有抑制作用。     

Potential oscillations across oil-water interface in the presence of the biological surfactant and amino acids or polypeptides

A lot of potential oscillations across oil-water interface ahve been designed by using various surfactants and biolagical surfactants in the aqueous phase and various amino acids or even polypeptides in the oil phase (nitrobenzene solution). Effects of the reactant’s concentration and the reaction temperature on the oscillating parameters have been studied. The oscillating mechanism has been discussed, and a model to the oscillating mechanism has been proposed which is proved qualitatively reasonable according to the simulation.     

青岛海葵强心活性多肽的分离纯化与氨基酸组成分析

青岛侧花海葵经组织破碎后，进行乙醇浸取和氯仿萃取，所得水相用超滤截取相对分子质量１００００以下的部分，冷冻干燥后用Ｓｅｐｈａｄｅｘ Ｇ－２５去除素与无机盐，活性部分利用中压系统进行阳离子交换层析，得到两个活性多肽吸收峰。这两个峰经反相层析后得到了在三甲基甘氨酸ＳＤＳ－聚丙烯酰胺凝胶电泳上显示单一条带的纯品，相对分子质量均在６０００左右，氨基酸组成结果表明，这些活性多肽与已经报道的Ａｐ－Ａ及Ａｐ－Ｂ