垂直板SDS-PAGE分析尿蛋白组分及临床应用的初步研究

目的：利用垂直板SDS-PAGE法进行尿蛋白谱分析,以区分尿蛋白类型。方法：收集患者及正常人体尿液,直接做垂直板十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）,用考马斯亮蓝染色,肉眼判定结果。结果：根据尿蛋白电泳图谱区分尿中含有不同分子量蛋白来判断属于肾小球性、肾小管性、混合性、溢出性及生理性蛋白尿。结论：本法分析尿蛋白组分操作简单方便、成本低、相对省时、结果直观易判定,适于推广使用。     

岩沙海葵毒素单克隆抗体的制备及其鉴定

目的建立岩沙海葵毒素（Palytoxin,PTX）高特异性单克隆抗体杂交瘤细胞株。方法将PTX偶联成具有免疫功能的PTX-PDP-KLH完全抗原,免疫雌性6—8周龄Balb／c小鼠,利用传统杂交瘤技术制备PTX单克隆抗体。并通过间接酶联免疫吸附测定（ELISA）方法筛选克隆阳性杂交瘤细胞株。结果获得能稳定分泌抗PTX单克隆抗体的杂交瘤细胞株B8,与载体蛋白没有发生交叉反应。SDS—PAGE分析表明,McAb B8在50KD和25KD处各出现一条条带,与IgG的重链和轻链的大小相符。结论研究制备了特异性单克隆抗体PTX,为进一步建立快速检测、鉴定海产品中岩沙海葵毒素的方法,奠定有效的实验基础。     

白纹伊蚊3日龄成蚊饱血前后唾液腺总蛋白谱

目的探讨3日龄白纹伊蚊雌蚊吸食糖水组和饱血组唾液腺总蛋白谱的差异。方法分别采用Pierce蛋白定量试剂盒和SDS-PAGE电泳分析白纹伊蚊3日龄吸食糖水组和饱血组成蚊唾液腺蛋白质浓度和蛋白谱。结果糖水组蚊虫单对唾液腺蛋白质质量约为（1．243Э0．460）μg,饱血组约为（0．945±0．460）μg;SDS—PAGE检测到糖水组唾液腺总蛋白有12条主带,糖水组与饱血组唾液腺总蛋白条带没有变化。结论白纹伊蚊雌蚊饱血后唾液腺总蛋白无特异条带诱导,但饱血后单对唾液腺总蛋白下降。     

Cholesterol reduction by methyl-beta-cyclodextrin attenuates the delta opioid receptor-mediated signaling in neuronal cells but enhances it in non-neuronal cells

Opioid receptors have been shown to be located in and regulated by lipid rafts/caveolae in caveolin-rich non-neuronal cells. Here, we found that caveolin-1 level was very low in rat brain and undetectable in NG108-15 cells, which endogenously express delta opioid receptors (DOR). Rat caudate putamen (CPu) membranes, NG108-15 cells and CHO cells stably transfected with FLAG-mouse-DOR (CHO-FLAG-mDOR) were homogenized, sonicated in a detergent-free 0.5M Na(2)CO(3) buffer and fractionated through discontinuous or continuous sucrose density gradients. About 70% of opioid receptors in CPu and DOR in both cell lines were present in low-density (5-20% sucrose) membrane domains enriched in cholesterol and ganglioside M1 (GM1), characteristics of lipid rafts in plasma membranes. In both cells, stimulation with permeable or non-permeable full agonists, but not with partial or inverse agonists, for 30min shifted approximately 25% of DORs out of rafts, by a naloxone-reversible and pertussis toxin-insensitive mechanism, which may undergo internalization. Methyl-beta-cyclodextrin (MCD) treatment greatly reduced cholesterol and shifted DOR to higher density fractions and decreased DPDPE affinities. MCD treatment attenuated DPDPE-induced [(35)S]GTPgammaS binding in CPu and NG108-15 cells, but enhanced it in CHO-FLAG-mDOR cells. In CHO-FLAG-mDOR cells, G(alphai) co-immunoprecipitated with caveolin-1, which was shown to inhibit G(alphai/o), and MCD treatment dramatically reduced the association leading to disinhibition. Thus, although localization in rafts and agonist-induced shift of DOR are independent of caveolin-1, lipid rafts sustain DOR-mediated signaling in caveolin-deficient neuronal cells, but appear to inhibit it in caveolin-enriched non-neuronal cells. Cholesterol-dependent association of caveolin-1 with and the resulting inhibition of G proteins may be a contributing factor.     

The heat shock response of Fusobacterium nucleatum

The heat-shock response of the oral Gram-negative bacterium Fusobacterium nucleatum was examined. Different strains of F. nucleatum were grown at 37 C. 42 degrees C and 48 C in the presence of [35S]methionine. Cellular proteins synthesised after shifts to higher temperatures were analysed by SDS-PAGE and autoradiography. Strains ATCC 10953, F1, F3 and Fev1 exhibited heat-shock response, and major proteins were observed at 60, 70 and 90 kDa. but increased protein synthesis was also observed for other proteins. Immunoblot analysis, using a panel of antibodies directed to epitopes on different known heat-shock proteins revealed cross-reactive proteins, indicating homology between Escherichia coli, Mycobacterium leprae and F. nucleatum heat shock proteins.     

Identification of some rabbit allergens as lipocalins

Rabbits are frequently used as laboratory animals or kept as domestic pets. Rabbit serum albumin and a 17-kDa protein referred to as Ory c 1 have previously been reported as allergens. Several other allergenic proteins have been recognized by crossed immuno-electrophoresis but have not been characterized. The aim of this study was to characterize the allergenic proteins present in rabbit saliva, urine and fur on the basis of molecular size and, where possible, to determine their amino acid sequences. Extracts from the male New Zealand white rabbit were used for developing specific direct RAST and RAST inhibition assays. Proteins in the extracts were separated by SDS-PAGE and the individual allergens identified by immunoblotting with serum from rabbit-allergic individuals. The N-termini of four allergens were sequenced. Saliva was the most potent extract. In total, 26 protein bands were recognized as allergens in the three extracts: 12 in saliva, seven in urine and seven in fur. Their molecular weights ranged from an 8-kDa species in saliva to an 80-kDa protein in urine. The N terminal sequences of an 18 kDa and a 21-kDa species in saliva, were identified as lipocalins with sequence similarity to a recently described odourant binding protein. This is the first evidence that allergens from the rabbit are members of the lipocalin superfamily of proteins, suggesting that similar mechanisms may be involved in eliciting the allergic response to rabbits. The 18 kDa allergen from saliva may be the previously named rabbit allergen, Ory c 1.     

半薄SDS-PAGE垂直式平板电泳法检测尿蛋白谱

蛋白尿是肾脏疾患的重要症状之一，其中蛋白的性质与构成（即尿蛋白谱）在诊断肾脏疾病及评估药物疗效等方面有着重要的参考价值。以往采用的蛋白电泳技术，如醋酸纤维薄膜、琼脂糖凝胶、免疫电泳、聚丙烯酰胺凝胶电泳（ＰＡＧＥ）、等电聚集以及ＳＤＳＰＡＧＥ圆盘电泳等方法虽各具优点，但与临床诊断所需的大量尿标本检测，以及蛋白成分高分辨率要求相比还存在着差距。本文介绍的半薄ＳＤＳＰＡＧＥ垂直式平板电泳［２，３］，并结合高敏银染［４］和激光密度扫描的方法，能够快速有效地分析尿液中蛋白质成分。１　材料和方法１．１　…     

Some probiotic and antibacterial properties of Lactobacillus acidophilus cultured from dahi a native milk product

In this study, different strains of Lactobacillus acidophilus from dahi were analyzed for certain probiotic and antibacterial properties. Initially, these strains were confirmed by the amplification of 16S rRNA regions and then screened for antibacterial activities against food borne pathogens. The phenotypic relationship between apparent antibacterial activity and cell wall proteins were established by cluster analysis. It was observed that those strains, which have prominent bands having size 22–25?kDa possess antibacterial activity. On the basis of wide spectrum of killing pattern, a strain LA06FT was further characterized that showed no change in its behavior when subjected to the antibiotic protected environment and grow well in acid-bile conditions. The bacteriocin produced by this strain has specific antibacterial activity of 5369.13?AU?mg^?1. It remained stable at 60–90?°C and pH range of 4.5–6.5 while proteolytic enzymes inactivate the bacteriocin that confirm its proteinic nature having molecular weight of ≤8.5?kDa.     

Serpin-1 splicing isoform J inhibits the proSpätzle-activating proteinase HP8 to regulate expression of antimicrobial hemolymph proteins in Manduca sexta

The innate immune system of insects include the Toll pathway, which is mediated by an extracellular serine proteinase cascade. In the tobacco hornworm, Manduca sexta, hemolymph proteinase 8 (HP8) promotes the synthesis of antimicrobial proteins by cleaving proSpätzle, the putative ligand of M. sexta Toll. HP8 has been observed to form a complex in hemolymph with M. sexta serpin-1, which has multiple alternative splicing isoforms. To investigate the regulation of HP8 and its processing of proSpätzle, we characterized the interaction of recombinant HP8 with serpin-1 isoform J (serpin-1J). Recombinant serpin-1J formed an SDS-stable complex with HP8 in vitro. The association rate constant of serpin-1J and HP8 was 1.3 × 10⁴ M⁻¹ s⁻¹, with a stoichiometry of inhibition of 5.4. Serpin-1J inhibited the cleavage of proSpätzle by HP8. Injection of serpin-1J into M. sexta larvae resulted in decreased bacteria-induced antimicrobial activity in hemolymph and reduced expression of cecropin, attacin and hemolin mRNA in fat body. Altogether, these results suggest that serpin-1J functions to inhibit HP8 and thereby modulates the concentration of active Spätzle to regulate the Toll pathway response in M. sexta.     

肺吸虫成虫抗原组分分析

用 IE、SDS-PAGE 和 Western blot 对肺吸虫成虫抗原(PwA)成分进行分析.结果 IE 出现2条粗而明显的沉淀带。SDS-PAGE 显示29条蛋白带(分子量范围为90.0～6.0 kD),其中有10条主带,分子量分别为57、53、49.5、46、42、30、27、25、14和13 kD.经 Western blot 试验显示,肺吸虫病人血清(抗体)与 PwA 应答,可出现3条蛋白带,分子量分别为25、13和8 kD。