果蝇NOMPC相互作用蛋白的筛选与鉴定

NOMPC是果蝇感受触觉的机械力敏感离子通道,属于瞬时受体电位(TRP)离子通道家族,机械力敏感离子通道通过怎样的机制被机械力激活?与NOMPC相互作用的蛋白有哪些?为了研究这些问题,本研究从果蝇NOMPC全长cDNA中扩增得到其N端的29个锚蛋白重复序列(ARs),ORF长度为3 039bp.然后将这29个ARs构建到表达载体pUAST-EGFP上,转染果蝇S2细胞后,通过免疫沉淀、质谱分析和Western blot筛选和鉴定NOMPC相互作用的蛋白,实验筛选出NOMPC N端的29ARs和NOMPC全长的相互作用蛋白,通过免疫共沉淀(Co-IP)实验,对可能与NOMPC存在相互作用的蛋白质进行验证,鉴定出Annexin B9、CG3195、CG3731、CG5374与NOMPC存在相互作用,为进一步研究NOMPC介导触觉转导的分子机制提供了基础.     

Interactions between HMG proteins (HMG1/2 and HMG14/17) and human ε-globin gene promoter (ε-promoter)

High mobility group (HMG) proteins are abundant non-histone proteins in the nuclei of eukaryocytes. It has been shown that HMG proteins may play important roles in the structure and function of chromatin. In the present study, thebinding of HMG proteins (HMG1/2 and HMG14/17) to the human ε-globin gene promoter (ε-promo- ter, -177-+1 bp) has been examined by using both the in vitro nucleosome reconstitution and the electrophoresis mobility shift assay (EMSA). We found that HMG1/2 proteins could bind to the naked ε-promoter DNA, however, HMG14/17 could not. Using the in vitro nucleosome recons- titution, we revealed that HMG14/17 could bind to the mononucleosome reconstituted in vitro with ε-promoter,whi- le HMG1/2 could not. Those results indicate that the binding of HMG proteins to ε-promoter is dynamic as the nucleo- some assembling and disassembling. Wespeculated that this selective binding of HMG proteins to ε-promoter might playa critical role in the regulation of ε-globin gene expression.     

采用阶段处理和多菌种固态发酵玉米秸秆的研究

目的 采用阶段处理和多菌种固态发酵玉米秸杆，提高玉米秸杆的饲料营养价值。方法 利用氨化法和白腐真菌Lx对玉米秸秆进行前处理，将康宁木霉和选育出的高活性黑曲霉Sy，瘤胃细菌X4，酵母Y2，接种于前处理过的玉米秸杆上进行多菌种共发酵。由正交试验得出最适培养条件。结果 在发酵温度30℃，pH5，发酵9d后，粗蛋白含量达24．61％，粗纤维降解率为48．37％。结论 该法为利用玉米秸杆生产蛋白饲料提供了新途径。     

Regulatory mechanisms involved in modulating RGS function

Regulator of G-Protein Signaling (RGS) refers to a conserved 120–125 amino acid motif that was first identified by its ability to negatively regulate G-Protein-Coupled Receptor (GPCR) signalling. Mechanistically, RGSs were found to regulate GPCR responses by binding to and stimulating the GTPase activity of the receptor-activated GTP-bound G α subunits. There are now over 25 mammalian RGSs containing proteins that are reported to carry out a variety of functions, many of which are unrelated to GPCR signalling. RGS proteins range in size from small proteins that contain little more than an RGS box to very large proteins that contain a variety of domains. The selectivity of function of the RGS proteins is attributable to the divergence of the RGS sequences as well as the presence of a variety of functional motifs, which allow them to interact with other proteins. Here we focus on the RGSs that are involved in modulating GPCR signalling by reviewing the diversity of the mechanisms involved in regulating these RGSs. Received 9 February 2006; received after revision 4 May 2006; accepted 22 May 2006     

肽泡的形态特征及其成膜蛋白的特性

小麦(Triticum aestivum)贮存蛋白经过纯化获得其中35kD一种蛋白质。该蛋白质在一定浓度的有机溶剂系统中经过超声波处理或搅拌,可以制成囊泡,并能包裹分子量从0.4～150kD的不同化合物(染料及抗体)。这种肽泡具有良好的稳定性,经低温冷冻干燥后,可成鳞片状,加水后复溶仍然保持肽泡的稳定性。这种特性称为DRV(Dehydration Rehydration Vesicles)性质。该蛋白质经修饰制定肽泡能包裹水溶性化合物,如水溶性染料,或不经修饰可包裹脂溶性化合物。这种蛋白质是由16种疏水性氨基酸残基组成,其N-末端为苯丙氨酸。     

高尔基体蛋白功能研究进展

高尔基体蛋白是一类定位在高尔基体表面上的螺旋卷曲蛋白家族.目前研究最为广泛的有11种高尔基体蛋白,它们分别定位在高尔基体堆栈不同的部位上.其中有3种定位在高尔基体正面膜囊表面上,高尔基体的反面膜囊表面和高尔基体膜囊边缘表面各定位4种高尔基体蛋白,它们以各自肽链羧基端或以跨膜结构域或与小的GTPase结合锚定到高尔基体膜...     

2-（2,3,5-三氮唑偶氮）-1,8-二羟基-3,6萘二磺酸分光光度法测定蛋白质

在pH2.96的氯乙酸-乙酸纳缓冲溶液中,新水溶性显色剂2-（2,3,5-三氮唑偶氮）-1,8-二羟基-3,6萘二磺酸与蛋白质结合形成复合物,其最大吸收波长位于505.80nm。用光度法研究了该结合反应的最佳条件,并在此基础上建立了一个测定蛋白质的新方法。在505.80nm处,牛蛋白与人蛋白在（0～80）mg/L范围内服从比尔定律。表观摩尔吸光系数为2.15×105L·mol^-1·cm^-1。该方法不仅具有高灵敏度和良好的选择性,而且简便快速。用于人血清样品中总蛋白质的测定,结果满意。     

NaCl胁迫下枸杞愈伤组织可溶性蛋白含量的变化

以枸杞愈伤组织为材料,分别接种于对照及含100,200,400mmol／L NaCl的培养基上,培养1,3,5,7,11d．实验结果表明,随着盐浓度的升高．枸杞愈伤组织可溶性蛋白含量降低,且随着时间的延长呈先上升后下降的趋势,即随着盐浓度的升高,培养1,3,5d时可溶性蛋白含量上升,5d后开始下降;培养11d时在不同含盐培养基上加入外源ABA,愈伤组织可溶性蛋白含量升高,通过SDS-PAGE电泳实验发现,当NaCl浓度为400mmol／L时,在愈伤组织中诱导出一条40．5kD的新蛋白．