禽多杀性巴氏杆菌粘附蛋白Cp39的交叉免疫保护作用

【目的】比较体内外增殖禽多杀性巴氏杆菌荚膜蛋白、天然粘附蛋白Cp39和重组粘附蛋白rCp39对小鼠的交叉保护作用。【方法】用NaCl提取法制备鸡胚尿囊液和DSA培养基增殖的C48-3株荚膜蛋白,并用电洗脱方法纯化Cp39蛋白,将rCp39蛋白以可溶形式表达在大肠杆菌BL21后,用Amylose Resin亲和层析柱纯化。分别以100μg剂量的鸡胚尿囊液增殖菌体荚膜蛋白、DSA培养基培养菌体荚膜蛋白、纯化的Cp39蛋白和rCp39蛋白通过皮下注射各试验组小鼠,生理盐水为对照组,第二次免疫后2周分别以A:1型菌C48-3株(6.7×102cfu)和A:3型菌C51-3株(1.1×103cfu)进行攻毒试验。采集免疫后小鼠血清,用ELISA法检测抗体水平,并计算免疫保护率,来评价4种抗原对小鼠的交叉保护效果。【结果】SDS-PAGE结果显示,体内外增殖禽多杀性巴氏杆菌荚膜蛋白的条带和分子量相似,且体内外表达的Cp39蛋白的分子量相同;ELISA结果表明Cp39免疫组小鼠和rCp39免疫组小鼠血清rCp39蛋白特异性抗体的水平显著高于其他两组(P0.05);保护试验表明,体外增殖菌体荚膜蛋白免疫组小鼠对同源C48-3株和异源C51-3株攻毒的保护率分别为100%和60%,鸡胚尿囊液增殖菌体荚膜蛋白免疫组小鼠、Cp39免疫组小鼠和rCp39免疫组小鼠对同源C48-3株和异源C51-3株攻毒的保护率分别为100%和80%。【结论】粘附蛋白Cp39是禽多杀性巴氏杆菌荚膜蛋白中的主要交叉保护抗原,可以作为禽霍乱亚单位疫苗。     

Proteins influencing foam formation in wine and beer: the role of yeast

This review focuses on the role of proteins in the production and maintenance of foam in both sparkling wines and beer. The quality of the foam in beer but especially in sparkling wines depends, among other factors, on the presence of mannoproteins released from the yeast cell walls during autolysis. These proteins are hydrophobic, highly glycosylated, and their molecular masses range from 10 to 200 kDa--characteristics that allow mannoproteins to surround and thus stabilize the gas bubbles of the foam. Both the production and stabilization of foam also depend on other proteins. In wine, these include grape-derived proteins such as vacuolar invertase; in beer, barley-derived proteins, such as LTP1, protein Z, and hordein-derived polypeptides, are even more important in this respect than mannoproteins.     

Screening and evaluation of antiparasitic and in vitro anticancer activities of Panamanian endophytic fungi

Many compounds produced by fungi have relevant pharmaceutical applications. The purpose of this study was to collect and isolate endophytic fungi from different regions of Panama and then to test their potential therapeutic activities against Leishmania donovani, Plasmodium falciparum, and Trypanosoma cruzi as well as their anticancer activities in MCF-7 cells. Of the 25 fungal isolates obtained, ten of them had good anti-parasitic potential, showing selective activity against L. donovani; four had significant anti-malarial activity; and three inhibited the growth of T. cruzi. Anticancer activity was demonstrated in four isolates. Of the active isolates, Edenia sp. strain F0755, Xylaria sp. strain F1220, Aspergillus sp. strain F1544, Mycoleptodiscus sp. strain F0194, Phomopsis sp. strain F1566, Pycnoporus sp. strain F0305, and Diaporthe sp. strain F1647 showed the most promise based on their selective bioactivity and lack of toxicity in the assays.     

Molecular and functional characterization of human pendrin and its allelic variants

Pendrin (SLC26A4, PDS) is an electroneutral anion exchanger transporting I(-), Cl(-), HCO(3)(-), OH(-), SCN(-) and formate. In the thyroid, pendrin is expressed at the apical membrane of the follicular epithelium and may be involved in mediating apical iodide efflux into the follicle; in the inner ear, it plays a crucial role in the conditioning of the pH and ion composition of the endolymph; in the kidney, it may exert a role in pH homeostasis and regulation of blood pressure. Mutations of the pendrin gene can lead to syndromic and non-syndromic hearing loss with EVA (enlarged vestibular aqueduct). Functional tests of mutated pendrin allelic variants found in patients with Pendred syndrome or non-syndromic EVA (ns-EVA) revealed that the pathological phenotype is due to the reduction or loss of function of the ion transport activity. The diagnosis of Pendred syndrome and ns-EVA can be difficult because of the presence of phenocopies of Pendred syndrome and benign polymorphisms occurring in the general population. As a consequence, defining whether or not an allelic variant is pathogenic is crucial. Recently, we found that the two parameters used so far to assess the pathogenic potential of a mutation, i.e. low incidence in the control population, and substitution of evolutionary conserved amino acids, are not always reliable for predicting the functionality of pendrin allelic variants; actually, we identified mutations occurring with the same frequency in the cohort of hearing impaired patients and in the control group of normal hearing individuals. Moreover, we identified functional polymorphisms affecting highly conserved amino acids. As a general rule however, we observed a complete loss of function for all truncations and amino acid substitutions involving a proline. In this view, clinical and radiological studies should be combined with genetic and molecular studies for a definitive diagnosis. In performing genetic studies, the possibility that the mutation could affect regions other than the pendrin coding region, such as its promoter region and/or the coding regions of functionally related genes (FOXI1, KCNJ10), should be taken into account. The presence of benign polymorphisms in the population suggests that genetic studies should be corroborated by functional studies; in this context, the existence of hypo-functional variants and possible differences between the I(-)/Cl(-) and Cl(-)/HCO(3)(-) exchange activities should be carefully evaluated.     

Polymorphism in the acetylcholinesterase gene of Musca domestica L. field populations in Turkey

Acetylcholinesterase (AChE), encoded by the Ace gene, is the primary target of organophosphates (OPs) and carbamates (CBs) in insects. Ace mutations have been identified in OP and CB resistant strains of Musca domestica. In this study, the Ace gene was partially amplified and sequenced at amino acid positions 260, 342, and 407 to determine the frequencies of these mutations in housefly samples collected from farms and garbage disposal sites of 16 provinces in the Aegean and Mediterranean regions of Turkey. In addition, the percent remaining AChE activities in these samples were assayed by using three OPs (malaoxon, paraoxon, and dichlorvos) and one CB (carbaryl) compound as inhibitors. In all the analyzed samples, 13 different combinations at the three amino acid positions were identified and the L/V260-A/G342-F/Y407 combination was found in the highest frequency. No susceptible individual was detected. The highest mean percent remaining AChE activities were detected in the individuals having the L260-A/G342-F/Y407 genotype when malaoxon and paraoxon were used as inhibitors and in the individuals with the L260-A342-F/Y407 combination when dichlorvos and carbaryl were used as inhibitors. The obtained data were heterogeneous and there was no exact correlation between the molecular genetic background and the resistance phenotypes of the flies. The findings of this study at the molecular and biochemical levels indicate the presence of significant control problems in the field.