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91.
Jaeho Lee Shanghyeon Kim Ji-Yeong Sim Daeun Lee Ha Hyung Kim Jae Sam Hwang Dong Gun Lee Zee-Yong Park Jae Il Kim 《生物化学与生物物理学报:生物膜》2019,1861(1):34-42
The emergence of drug-resistant pathogenic bacteria threatens human health. Resistance to existing antibiotics is increasing, while the emergence of new antibiotics is slowing. Cationic antimicrobial peptides (CAMPs) are fascinating alternative antibiotics because they possess a broad spectrum of activity, being active against both Gram-positive and Gram-negative bacteria including those resistant to traditional antibiotics. However, low bioavailability resulting from enzymatic degradation and attenuation by divalent cations like Mg2+ and Ca2+ limits their use as antibiotic agents. Here, we report the design of new CAMPs showing both high antibacterial activity and serum stability under physiological ion concentrations. The peptides were designed by applying two approaches, the use of d-enantiomer and lipidation. Based on the sequence of the CopW (LLWIALRKK-NH2), a nonapeptide derived from coprisin, a series of novel d-form CopW lipopeptides with different acyl chain lengths (C6, C8, C10, C12, C14, and C16) were synthesized and evaluated with respect to their activity and salt sensitivity. Among the analogs, the d-form lipopeptide dCopW3 exhibited MIC values ranging from 1.25 to 5?μM against multidrug-resistant bacteria. Significantly, this compound did not induce bacterial resistance and was highly stable in human serum proteases. The results emphasize the potential of cationic d-form lipopeptide as therapeutically valuable antibiotics for treating drug-resistant bacterial infections. 相似文献
92.
Identification of post-translational modifications (PTMs) is important to understanding the biological functions of proteins. MS/MS is a useful tool to identify PTMs. Most existing search tools are restricted to take only a few types of PTMs as input. Here we describe a new algorithm, called MOD(i) (pronounced "mod eye"), that rapidly searches for all known types of PTMs at once without limiting a multitude of modified sites in a peptide. MOD(i) introduces the notion of a tag chain, a combination structure made from multiple sequence tags, that effectively localizes modified regions within a spectrum and overcomes de novo sequencing errors common in tag-based approaches. MOD(i) showed its performance competence by identifying various types of PTMs in analysis of PTM-rich proteins such as glyceraldehyde-3-phosphate dehydrogenase and lens protein. We demonstrated that MOD(i) innovatively manages the computational complexity of identifying multiple PTMs in a peptide, which may exist in a greater variety than usually expected. In addition, it is suggested that MOD(i) has great potential to discover novel modifications. 相似文献
93.
Jun SY Park KM Choi KW Jang MK Kang HY Lee SH Park KH Cha J 《Biotechnology letters》2008,30(4):743-748
To develop a new skin whitening agent, arbutin-β-glycosides were synthesized and evaluated for their melanogenesis inhibitory
activities. Three active compounds were synthesized via the transglycosylation reaction of Thermotoga neapolitana β-glucosidase and purified by recycling preparative HPLC. As compared with arbutin (IC50 = 6 mM), the IC50 values of these compounds were 8, 10, and 5 mM for β-d-glucopyranosyl-(1→6)-arbutin, β-d-glucopyranosyl-(1→4)-arbutin, and β-d-glucopyranosyl-(1→3)-arbutin, respectively. β-d-Glucosyl-(1→3)-arbutin also exerted the most profound inhibitory effects on melanin synthesis in B16F10 melanoma cells. Melanin
synthesis was inhibited to a significant degree at 5 mM, at which concentration the melanin content was reduced to below 70%
of that observed in the untreated cells. Consequently, β-d-glucopyranosyl-(1→3)-arbutin is a more effective depigmentation agent and is also less cytotoxic than the known melanogenesis
inhibitor, arbutin. 相似文献
94.
By the fusion of lymphocytes from hyperimmunized people with heteromyeloma cells, 600 human hybridoma cell lines were generated. Even though seven cell lines produced antibodies against tetanus toxoid, only two antibodies from hybrid CH8 and CH5 only neutralized the tetanus toxin and completely protected the mice that had been challenged with the toxin even at the level of 90 mean lethal dose. The cDNA of light (L) chain and heavy (H) chain variable region was isolated, and then inserted into expression vectors containing human IgG constant regions. After transfection of the recombinant human IgG gene into Chinese Hamster Ovary (CHO) cells, transformants secreting the complete human antibody were selected. The recombinant human antibodies produced from CHO cells possessed neutralizing activity against tetanus toxin just like the original human antibodies produced from human hybridoma cell lines. Western blot analysis showed that rCH8 and rCH5 antibodies recognized the H chain of tetanus toxin and did not bind to its L chain. The neutralizing test showed that HmAb rCH5 had 4.55IU and HmAb rCH8 had 1.09IU/100 micro g of IgG, respectively. Mixing of the two HmAbs resulted in synergistic effects. On a weight basis (IU/100 micro g IgG), the highest potency values were obtained when the two HmAbs were combined in equal quantity. The neutralizing activity of rCH8 and rCH5 mixture was 6.94IU/100 micro g IgG. 相似文献
95.
The Importance of Confined Sulfur Nanodomains and Adjoining Electron Conductive Pathways in Subreaction Regimes of Li‐S Batteries 下载免费PDF全文
Jungjin Park Eui Tae Kim Chunjoong Kim Jeffrey Pyun Hyung‐Seok Jang Jaeho Shin Jang Wook Choi Kookheon Char Yung‐Eun Sung 《Liver Transplantation》2017,7(19)
Polysulfide dissolution into the electrolyte and poor electric conductivity of elemental sulfur are well‐known origins for capacity fading in lithium–sulfur batteries. Various smart electrode designs have lately been introduced to avoid these fading mechanisms, most of which demonstrate significantly improved cycle life. Nevertheless, an in‐depth understanding on the effect of sulfur microstructure and nanoscale electron transport near sulfur is currently lacking. In this study, the authors report an organized nanocomposite comprising linear sulfur chains and oleylamine‐functionalized reduced graphene oxide (O‐rGO) to achieve robust cycling performance (81.7% retention after 500 cycles) as well as to investigate the reaction mechanism in different regimes, i.e., S8 dissolution, polysulfide conversion, and Li2S formation. In the nanocomposite, linear sulfur chains terminate with 1,3‐diisopropylbenzene are covalently linked to O‐rGO. The comparison with control samples that do not contain either the capping of sulfur chains or O‐rGO reveals the synergistic interplay between both treatments, simultaneously unveiling the distinct roles of confined sulfur nanodomains and their adjoining electron pathways in different reaction regimes. 相似文献
96.
Lithium‐Sulfur Batteries: The Importance of Confined Sulfur Nanodomains and Adjoining Electron Conductive Pathways in Subreaction Regimes of Li‐S Batteries (Adv. Energy Mater. 19/2017) 下载免费PDF全文
97.
Recent Progress on Spray Pyrolysis for High Performance Electrode Materials in Lithium and Sodium Rechargeable Batteries 下载免费PDF全文
Yujie Zhu Seung Ho Choi Xiulin Fan Jaeho Shin Zhaohui Ma Michael R. Zachariah Jang Wook Choi Chunsheng Wang 《Liver Transplantation》2017,7(7)
Advanced electrode materials have been intensively explored for next‐generation lithium‐ion batteries (LIBs), and great progresses have been achieved for many potential candidates at the lab‐scale. To realize the commercialization of these materials, industrially‐viable synthetic approaches are urgently needed. Spray pyrolysis (SP), which is highly scalable and compatible with on‐line continuous production processes, offers great fidelity in synthesis of electrode materials with complex architectures and chemistries. In this review, motivated by the rapid advancement of the given technology in the battery area, we have summarized the recent progress on SP for preparing a great variety of anode and cathode materials of LIBs with emphasis on their unique structures generated by SP and how the structures enhanced the electrochemical performance of various electrode materials. Considering the emerging popularity of sodium‐ion batteries (SIBs), recent electrode materials for SIBs produced by SP will also be discussed. Finally, the powerfulness and limitation along with future research efforts of SP on preparing electrode materials are concisely provided. Given current worldwide interests on LIBs and SIBs, we hope this review will greatly stimulate the collaborative efforts among different communities to optimize existing approaches and to develop innovative processes for preparing electrode materials. 相似文献
98.
Herrmann F Lee J Bedford MT Fackelmayer FO 《The Journal of biological chemistry》2005,280(45):38005-38010
Arginine methylation is a posttranslational protein modification catalyzed by a family of protein arginine methyltransferases (PRMT), the predominant member of which is PRMT1. Despite its major role in arginine methylation of nuclear proteins, surprisingly little is known about the subcellular localization and dynamics of PRMT1. We show here that only a fraction of PRMT1 is located in the nucleus, but the protein is predominantly cytoplasmic. Fluorescence recovery after photobleaching experiments reveal that PRMT1 is highly mobile both in the cytoplasm and the nucleus. However, inhibition of methylation leads to a significant nuclear accumulation of PRMT1, concomitant with the appearance of an immobile fraction of the protein in the nucleus, but not the cytoplasm. Both the accumulation and immobility of PRMT1 is reversed when re-methylation is allowed, suggesting a mechanism where PRMT1 is trapped by unmethylated substrates such as core histones and heterogeneous nuclear ribonucleoprotein proteins until it has executed the methylation reaction. 相似文献
99.
100.
Seo EJ Yoo SH Oh KW Cha J Lee HG Park CS 《Bioscience, biotechnology, and biochemistry》2004,68(5):1146-1148
An exopolysaccharide-producing Gram negative bacterium was isolated and determined to be a Sphingomonas sp. (CS101). A sugar composition analysis of an exopolysaccharide indicated that the Sphingomonas sp. CS101 secreted an exopolysaccharide composed of glucose, mannose, fucose, and rhamnose in the ratio of 2.1:1.1:1.0:0.1, suggesting that this exoplysaccharide is an unusual type of sphingan family. The mean molecular weight of the exopolysaccharide was determined to be 4.2x10(5) Da by size exclusion chromatography coupled with multi-angle laser-light scattering (SEC/MALLS) analysis. An exopolysaccharide was produced up to 17 g/l (pH 7; 30 degrees C) with the optimal medium condition over 4 days of cultivation. 相似文献