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1.
Antimicrobial peptides are a class of proteins with antibacterial functions. In this study, the anti-lipopolysaccharide factor isoform 3 gene (ALFPm3), encoding an antimicrobial peptide from Penaeus monodon with a super activity was expressed in Chlamydomonas reinhardtii, which would develop a microalga strain that can be used for the antimicrobial peptide production. To construct the expression cluster, namely pH2A-Pm3, the codon optimized ALFPm3 gene was fused with the ble reporter by 2A peptide and inserted into pH124 vector. The glass-bead method was performed to transform pH2A-Pm3 into C. reinhardtii CC-849. In addition to 8 μg/mL zeocin resistance selection, the C. reinhardtii transformants were further confirmed by genomic PCR and RT-PCR. Western blot analysis showed that the C. reinhardtii-derived ALFPm3 (cALFPm3) was successfully expressed in C. reinhardtii transformants and accounted for 0.35% of the total soluble protein (TSP). Furthermore, the results of antibacterial assay revealed that the cALFPm3 could significantly inhibit the growth of a variety of bacteria, including both Gram-negative bacteria and Gram-positive bacteria at a concentration of 0.77 μM. Especially, the inhibition could last longer than 24 h, which performed better than ampicillin. Hence, this study successfully developed a transgenic C. reinhardtii strain, which can produce the active ALFPm3 driven from P. monodon, providing a potential strategy to use C. reinhardtii as the cell factory to produce antimicrobial peptides.  相似文献   
2.
经过蛋白质着色动力学的研究,发现蛋白质着色的行为遵循数学模型Y=aX^b。在pH2-6范围内,蛋白质上染料随染溶pH的下降而上升,在15-30℃温度范围内,蛋白质上染率随温度上升略有提高,当温度超过30℃时,蛋白质上染率逐渐下降。染浴中添加稀土对蛋白质有较强的促染效果,其实质是染浴中蛋白质首先对稀土高价阳离子进行结合,再通过高价阳离子对色素进吸附。  相似文献   
3.
应用了GC/MS方法分析炼油厂汽提污水中的有机物,其结果可作为实用除油技术的依据。  相似文献   
4.
抗菌肽与抗生素的体外抗菌效果比较   总被引:17,自引:0,他引:17  
应用由 Hancock实验室改进的微量肉汤稀释法测定了 cecropin P1、cecropin A、magainin 2、defensin 1、bactenecin、lactoferricin和 indolicidin等 7种抗菌肽和盐酸金霉素、去甲万古霉素、土霉素、强力霉素等 4种抗生素的体外抗菌活性 ,并且使用薄层琼脂糖孔穴扩散法比较了抗菌肽中 cecropin P1和 cecropin A与土霉素和呋喃唑酮对大肠杆菌 K88的抑菌效果。结果发现 ,抗菌肽与抗生素一样对几种革兰氏阳性菌和阴性菌都有不同程度的抗菌效果。其中 cecropin A、cecropin P1和 defensin1对大肠杆菌的 2个菌株 ATCC2 5 92 2和 K88的抗菌活性高于抗生素 ,defensin1是各种抗菌肽中对金黄色葡萄球菌抗菌效果最好的。抗生素对试验用金黄色葡萄球菌的抑制活性总体上要好于抗菌肽。与抗生素相比 ,cecropin A、cecropin P1和 indolicidin对猪霍乱沙门氏菌和鼠伤寒沙门氏菌具有更好的抗菌效果。另外 ,抗菌肽的抑菌圈边缘十分清晰 ,而抗生素的整个抑菌圈都比较模糊且界线不明。因此 ,从抗菌效果方面考虑 ,抗菌肽可以代替抗生素用于疾病的预防和治疗  相似文献   
5.
Cationic antimicrobial peptides are present throughout the plant and animal kingdoms and bear striking structural and functional similarities across species lines. They provide primitive, nonspecific means of combating a variety of bacteria, fungi, enveloped viruses, and protozoa. Some are also cytotoxic against host cells, including neoplastic cells. Cationic antimicrobial peptides may play various roles in inflammation and tissue repair. Antimicrobial peptides are found in epithelial tissues regularly exposed to microbial attack as well as in cells whose primary function is defense against potential pathogens. They constitute an important part of the nonoxidative antimicrobial arsenal of leukocytes. They are preformed and/or readily synthesized when the cells are stimulated by exposure to pathogens. They exert their effects directly by inserting into membranes of target cells and forming ion channels which increase membrane permeability; however, antimicrobial peptides can also act as opsonins to facilitate phagocytosis. Resistance to defensins is a virulence factor for organisms such as Salmonella sp. The study of cationic antimicrobial peptides is increasing our understanding of innate immunity, inflammation, and the pathogenesis of genetic diseases such as specific granule disease in humans. Therapeutic applications of antimicrobial peptides are currently under investigation.  相似文献   
6.
This review provides an overview of members of the ATP-binding cassette (ABC) and major facilitator superfamily (MFS) of transporters identified in filamentous fungi. The most common function of these membrane proteins is to provide protection against natural toxic compounds present in the environment of fungi, such as antibiotics produced by other microorganisms. In plant pathogenic fungi, these transporters can also be an important determinant of virulence on host plants by providing protection against plant defence compounds or mediating the secretion of host-specific toxins. Furthermore, they play a critical role in determining base-line sensitivity to fungicides and other antimycotic agents. Overexpression of some of these transporters can lead to the development of resistance to chemically-unrelated compounds, a phenomenon described as multidrug resistance (MDR). This has been observed in a variety of organisms and can impose a serious threat to the effective control of pathogenic fungi.  相似文献   
7.
Laboratory and greenhouse experiments were conducted to determine the effects of aqueous extract and the debris of Mile-a-Minute ( Mikania micrantha H.B.K.) on the germination and growth of four test species, viz. tomato ( Lycopersicon esculentum Mill.), Chinese cabbage ( Brassica chinensis L.), corn ( Zea mays L.) and long bean ( Vigna sesquipedalis L.). Germination percentage, radicle length and fresh weight of two crops, Chinese cabbage and tomato, decreased progressively when plants were exposed to increasing concentrations (12.5, 25, 37.5 and 50 g L−1) of aqueous extract of Mikania , but did not affect those of corn and long bean seedlings. The emergence of tomato and Chinese cabbage was greatly reduced when Mikania debris was incorporated into the soil, irrespective of the amount of debris and the decomposition period. In contrast, the emergence of corn and long bean seedlings was not affected. The application of fertilizer (NPK 15 : 15 : 15) enhanced the fresh weight of all seedlings tested as compared with those not supplied with the fertilizer. Four compounds were identified in the leaf extract of Mikania , viz. caffeic acid, p -hydroxybenzaldehyde, resorcinol and vanillic acid.  相似文献   
8.
Botryodiplodia theobromae, Colletotrichum gloeosporioides andGliocephalotrichum microchlamydosporum are the causal fungi of the rambutan postharvest diseases stem-end rot, anthracnose and brown spot, respectively. Two different treatments of rambutan fruits(Nephelium lappaceum) against the three pathogens were compared: potassium metabisulphite (250 ppm) or cinnamaldehyde (30 ppm), each combined withTrichoderma harzianum (TrH 40). The application of TrH 40 and potassium metabisulphite effectively controlled the incidence and severity of the three postharvest diseases and maintained the overall quality and color of the fruit under low temperature storage at 13.5°C and 95% r.h. for 18 days. The greatest effect of this treatment was shown onG. microchlamydosporum. Cinnamaldehyde affected the growth and germination of TrH 40, whereas potassium metabisulphite did not. http://www.phytoparasitica.org posting Nov. 4, 2001.  相似文献   
9.
Cytochrome P450 monoxygenase converts arachionic acid to four epoxyeicosatrienoic acid regiosomes: 5, 6-EET (epoxyeicosatrienoic acid); 8, 9-EET; 11, 12-EET and 14, 15-EET. Recent studies show that EETs are involved in signal transduction. EETs open Ca2+-sensit ive K+ channel and inhibit Na+ channel, Ca2+-sensitive Cl- channel and so on. What is more, EETs have been demonstrated to activate PP60c-src and initiate a tyrosine kinase cascade that mediates mitogenic effects.  相似文献   
10.
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