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1.
Dongliang Liu Jun Liu Weilan Wang Lijie Xia Jianhua Yang Surong Sun Fuchun Zhang 《Food biophysics》2016,11(4):319-331
Cecropin XJ, as a heat stable antimicrobial peptide (AMP), displayed broad bacteriostatic activities, effectively inhibited proliferation of cancer cells and induced cell apoptosis in vitro. However, it exhibited little hemolytic activity and very low cytotoxicity to erythrocytes and normal cells. Although exerts multiple remarkable bioactivities, the refined molecular conformation of native Cecropin XJ remains unsolved. The aim of the present study is to comprehensively investigate the physicochemical characteristics and structure-function relationship of this antimicrobial peptide by using a series of bioinformatics and experimental approaches. In this study, we revealed that the mature Cecropin XJ consists of 41 amino acids, containing two α-helical structures from Lys7 to Lys25 and from Ala29 to Ile39. The phylogenetic tree indicated that Cecropin XJ belongs to the Class I AMPs of cecropin family. Hydrophobic analysis showed Cecropin XJ is a typical amphiphilic molecule. The surface of Cecropin XJ was found to have a much wide range of electrostatic potential from ?83.243 to +83.243. The amphipathicity and surface potential of Cecropin XJ partially supported the AMP pore-forming hypothesis. Scanning electron microscopy experimentally confirmed the damages of Cecropin XJ to microbial membrane. Four predicted docking sites respectively for magnesium ion (Mg2+), adenosine diphosphate (ADP), bacteriopheophytin (BPH), and guanosine triphosphate (GTP) were found on the surface of Cecropin XJ. Thereinto, Mg2+ was experimentally proved to suppress the antibacterial activity of Cecropin XJ; both GTP and ADP enhanced the bactericidal activities to varying degrees. The present study provides a foundation for further investigation of molecular evolution, structural modification, and functional mechanisms of Cecropin XJ. 相似文献
2.
3.
Juan Huang Jialin Wang Lijie Gu Jinfang Bao Jun Yin Zhihuan Tang Ling Wang Weijie Yuan 《PloS one》2013,8(11)
A low-protein diet supplemented with ketoacids maintains nutritional status in patients with diabetic nephropathy. The activation of autophagy has been shown in the skeletal muscle of diabetic and uremic rats. This study aimed to determine whether a low-protein diet supplemented with ketoacids improves muscle atrophy and decreases the increased autophagy observed in rats with type 2 diabetic nephropathy. In this study, 24-week-old Goto-Kakizaki male rats were randomly divided into groups that received either a normal protein diet (NPD group), a low-protein diet (LPD group) or a low-protein diet supplemented with ketoacids (LPD+KA group) for 24 weeks. Age- and weight-matched Wistar rats served as control animals and received a normal protein diet (control group). We found that protein restriction attenuated proteinuria and decreased blood urea nitrogen and serum creatinine levels. Compared with the NPD and LPD groups, the LPD+KA group showed a delay in body weight loss, an attenuation in soleus muscle mass loss and a decrease of the mean cross-sectional area of soleus muscle fibers. The mRNA and protein expression of autophagy-related genes, such as Beclin-1, LC3B, Bnip3, p62 and Cathepsin L, were increased in the soleus muscle of GK rats fed with NPD compared to Wistar rats. Importantly, LPD resulted in a slight reduction in the expression of autophagy-related genes; however, these differences were not statistically significant. In addition, LPD+KA abolished the upregulation of autophagy-related gene expression. Furthermore, the activation of autophagy in the NPD and LPD groups was confirmed by the appearance of autophagosomes or autolysosomes using electron microscopy, when compared with the Control and LPD+KA groups. Our results showed that LPD+KA abolished the activation of autophagy in skeletal muscle and decreased muscle loss in rats with type 2 diabetic nephropathy. 相似文献
4.
A Kuroiwa K Matsubara T Nagase N Nomura J K Seong A Ishikawa R V Anunciado K Tanaka T Yamagata J S Masangkay V B Dang T Namikawa Y Matsuda 《The Journal of heredity》2001,92(3):282-287
The direct R-banding fluorescence in situ hybridization (FISH) method was used to map 18S-28S ribosomal RNA genes and 10 human cDNA clones on the chromosomes of the musk shrew (Suncus murinus). The chromosomal locations of 18S-28S ribosomal RNA genes were examined in the five laboratory lines and wild animals captured in the Philippines and Vietnam, and the genes were found on chromosomes 5, 6, 9, and 13 with geographic variation. The comparative mapping of 10 cDNA clones of human chromosome 1 demonstrated that human chromosome 1 consisted of at least three segments homologous to Suncus chromosomes (chromosomes 7, 10, and 14). This approach with the direct R-banding FISH method is useful for constructing comparative maps between human and insectivore species and for explicating the process of chromosomal rearrangements during the evolution of mammals. 相似文献
5.
We have identified the domain of the human c-myc protein (c-Myc) produced in Escherichia coli that is responsible for the ability of the protein to bind sequence-nonspecific DNA. Using analysis of binding of DNA by proteins transferred to nitrocellulose, DNA-cellulose chromatography, and a nitrocellulose filter binding assay, we examined the binding properties of c-Myc peptides generated by cyanogen bromide cleavage, of mutant c-Myc, and of proteins that fuse portions of c-Myc to staphylococcal protein A. The results of these analyses indicated that c-Myc amino acids 265 to 318 were responsible for DNA binding and that other regions of the protein (including a highly conserved basic region and a region containing the leucine zipper motif) were not required. Some mutant c-Mycs that did not bind DNA maintained rat embryo cell-cotransforming activity, which indicated that the c-Myc property of in vitro DNA binding was not essential for this activity. These mutants, however, were unable to transform established rat fibroblasts (Rat-1a cells) that were susceptible to transformation by wild-type c-Myc, although this lack of activity may not have been due to their inability to bind DNA. 相似文献
6.
Contractile responses to adrenergic nerve stimulation are enhanced with removal of endothelium in rat caudal artery 总被引:6,自引:0,他引:6
Removal of the endothelium from isolated perfused rat caudal arteries produced a two fold increase in the contractile response to transmural nerve stimulation. Pretreatment with 6-hydroxydopamine eliminated the contractile response to adrenergic nerve stimulation but failed to uncover any vasodilatory effect of electrical stimulation, either directly on smooth muscle or via non-adrenergic nerves. Endothelial removal also produced two and four fold enhancement of the contractile responses to the selective alpha 1- and alpha 2-adrenoceptor agonists methoxamine and B-HT 920. However, pKB values for prazosin and yohimbine versus both agonists indicate that both methoxamine and B-HT 920 are acting primarily at alpha 1-adrenoceptors in this tissue. These results provide evidence that endothelial factors released either at basal levels or by the stimulation of agonists play a significant physiological role in modifying the contractile responses of blood vessels. 相似文献
7.
An efficient method for generating embryonic mosaics using a yeast site-specific recombinase (FLP), under the control of a heat shock promoter, is described. FLP-recombinase can promote mitotic exchange between homologous chromosomes that contain FRT (FLP Recombination Target) sequences. To demonstrate the efficiency of FLP-recombinase to generate embryonic mosaics, clones of the recessive and cell autonomous mutation armadillo (arm), detected by their ability to differentiate ectopic denticles in the naked cuticle of each abdominal segment, have been induced. We have analyzed the parameters of FLP-recombinase induced embryonic mitotic recombination and have demonstrated that clones can be efficiently induced during the postblastoderm mitotic divisions. We discuss applications of this technique for the analyses of the roles of various mutations during embryonic patterning. 相似文献
8.
9.
The myositis-specific anti-Jo-1 autoantibody, which is directed against histidyl-tRNA-synthetase, is found in 30% of polymyositis patients. The Jo-1 antigen has been reported to be a nuclear antigen by some authors. On the contrary we show that less than 2% of the total histidyl-tRNA and lysyl-tRNA synthetase activities are associated with purified rat liver nuclei or the hepatocyte intermediate filament-nuclear fraction. In the presence of polyethylene glycol, in which the high Mr multi-enzyme complex containing lysyl-tRNA synthetase is insoluble, 65% of the lysyl-tRNA synthetase and only 15% of histidyl-tRNA synthetase activities remained associated with the cytoskeletal framework. The Jo-1 antigen exhibited a diffuse granular cytoplasmic distribution in cultured rat hepatocytes as determined by indirect immunofluorescent microscopy. Hence, the Jo-1 antigen is cytoplasmic and unassociated with the cytoskeletal framework or high Mr synthetase complex in situ. 相似文献
10.
Comitogenic effect of solid-phase immobilized anti-1F7 on human CD4 T cell activation via CD3 and CD2 pathways 总被引:14,自引:0,他引:14
N H Dang Y Torimoto K Deusch S F Schlossman C Morimoto 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(11):4092-4100
We have recently developed a mAb, anti-1F7, which defines a family of structures found to include the molecule recognized by anti-Ta1 (CD26). In this paper, we demonstrated that binding of 1F7 by solid-phase immobilized anti-1F7 mAb but not anti-Ta1 mAb has a comitogenic effect by inducing proliferation of human CD4+ T lymphocytes in conjunction with submitogenic doses of anti-CD3 or anti-CD2. The proliferative response induced via the CD3-1F7 or CD2-1F7 pathways is associated with the IL-2 autocrine pathway, including IL-2 production. IL-2R expression and anti-IL-2R (Tac) inhibition. Furthermore, solid-phase immobilization of anti-1F7 but not anti-Ta1 acts in conjunction with submitogenic doses of PMA to mediate a comitogenic effect in the absence of anti-CD3 or anti-CD2, leading to CD4+ T cell proliferation. PMA treatment, in the meantime, leads to enhanced expression of 1F7 on the T cell surface. Despite its functional association with both pathways of activation, however, the 1F7 structure is not comodulated with the CD3/TCR complex nor the CD2 molecule. These findings thus suggest that the CD26 Ag is involved in CD3 and CD2-induced human CD4+ T cell activation. 相似文献