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Xiao Liu,Jianan Guan,Guanghong Lai,Yunsheng Zheng,Ziming Wang,Suping Cui,Mingzhang Lan,Huiqun Li 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.55 No.-
Certain clays attached around the aggregates contaminate the concrete and also greatly affect the concrete workability, the mechanism of which was investigated through calculating the volume change of solid and liquid phases of concrete mixture containing clay. To minimize this detrimental effect, two novel designs based on the transfer of theory and techniques from polymer science, i.e., molecular design of polycarboxylate superplasticizer (PCE), were proposed. The one was “intercalator” synthesized via Hofmann rearrangement and cationization, and the other was “star-shaped polycarboxylate super- plasticizer (SPCE)” synthesized via a route of “core first and arm second”. The results of Infrared Spectroscopy (IR) and 1H Nuclear Magnetic Resonance (1H NMR) confirm the designed structures. The applications of these polymers in clay-contaminated cement paste and concrete were tested. The results showed that, the dispersing capacities of “Intercalator + Comb-shaped polycarboxylate superplasticizer (CPCE)” and SPCE were less affected by adding clay in both cement paste and concrete. Adsorption and Xray diffraction (XRD) experiments revealed less harmful intercalation for SPCE and preferential occupation in the interlayer space of clay for intercalator to protect other workable PCEs. It is interesting that optimizing charge characteristic and “disassembling-assembling” molecular arrangement can contribute to excellent resistance towards clay. The aim of this study is to offer two promising alternatives, which attractively provide the theoretical basis and technological application in researching advanced materials in clay-contaminated concrete.
( Huei-fen Lo ),( Meng-chun Chi ),( Min-guan Lin ),( Yuan-gin Lan ),( Tzu-fan Wang ),( Long-liu Lin ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.9
In the present study, the stabilizing effect of four different biological osmolytes on Bacillus licheniformis γ-glutamyl transpeptidase (BlGGT) was investigated. BlGGT appeared to be stable under temperatures below 40°C, but the enzyme retained less than 10% of its activity at 60°C. The tested osmolytes exhibited different degrees of effectiveness against temperature inactivation of BlGGT, and sucrose was found to be the most effective among these. The use of circular dichroism spectroscopy for studying the secondary structure of BlGGT revealed that the temperature-induced conformational change of the protein molecule could be prevented by the osmolytes. Consistently, the molecular structure of the enzyme was essentially conserved by the osmolytes at elevated temperatures as monitored by fluorescence spectroscopy. Sucrose was further observed to counteract guanidine hydrochloride (GdnHCl)- and urea-induced denaturation of BlGGT. Taken together, we observed evidently that some well-known biological osmolytes, especially sucrose, make a dominant contribution to the structural stabilization of BlGTT.
Guo, Yu,Xu, Li-Sha,Zhang, Ding,Liao, Ya-Ping,Wang, Hai-ping,Lan, Zhi-Hui,Guan, Wei-Jun,Liu, Chang-Qing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8
Objectives: To investigate the effects of betaine on HeLa cell growth and apoptosis and molecular mechanisms. Materials and Methods: Concentrations of 0.1, 1.0, 5.0, 20.0, 100.0 mg/ml of betaine were used to evaluate the anticancer efficacy for HeLa cells respectively, and MCF-10A was also detected as a normal diploid cell control. Results: We found that proliferation of HeLa cells was inhibited significantly upon exposure to increasing betaine levels with the MTT test (p<0.05). The percentage of S phase cells in the low dose groups (<5mg/ml) were distinctly higher than in high dose groups, and the rates of Sub-G1 phase were the opposite (p<0.01); A high concentration of betaine (>5.0mg/ml) significantly promoted the apoptosis of HeLa cells (p<0.01). SOD activities of the low dose groups were slightly higher than the control group (p<0.05) and there were obvious synchronicity and correlation among the expression of promoting apoptosis genes Bax, P53, Caspase 3 and apoptosis suppression gene Bcl-2. In response to an apoptosis-inducing stimulus, p53 and cyclin D1 could be activated with blockage of the cell cycle at G1/S or S/G2 checkpoints. Conclusions: Our data showed that betaine could promote HeLa cells proliferation in vitro at low concentrations. In contrast, high concentrations could significantly inhibit cell growth and migration, and induce apoptosis of HeLa cells through caspase 3 signaling and further promoted necrosis. This might imply that betaine exhibits tumoricidal effects and acts as a biological response modifier in cancer treatment by inducing apoptosis and cell cycle arrest in a dose and time-dependent manner.
1,3,5-Triazine-Cored Maltoside Amphiphiles for Membrane Protein Extraction and Stabilization
Ghani, Lubna,Munk, Chastine F.,Zhang, Xiang,Katsube, Satoshi,Du, Yang,Cecchetti, Cristina,Huang, Weijiao,Bae, Hyoung Eun,Saouros, Savvas,Ehsan, Muhammad,Guan, Lan,Liu, Xiangyu,Loland, Claus J.,Kobilka American Chemical Society 2019 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.141 No.50
<P>Despite their major biological and pharmacological significance, the structural and functional study of membrane proteins remains a significant challenge. A main issue is the isolation of these proteins in a stable and functional state from native lipid membranes. Detergents are amphiphilic compounds widely used to extract membrane proteins from the native membranes and maintain them in a stable form during downstream analysis. However, due to limitations of conventional detergents, it is essential to develop novel amphiphiles with optimal properties for protein stability in order to advance membrane protein research. Here we designed and synthesized 1,3,5-triazine-cored dimaltoside amphiphiles derived from cyanuric chloride. By introducing variations in the alkyl chain linkage (ether/thioether) and an amine-functionalized diol linker (serinol/diethanolamine), we prepared two sets of 1,3,5-triazine-based detergents. When tested with several model membrane proteins, these agents showed remarkable efficacy in stabilizing three transporters and two G protein-coupled receptors. Detergent behavior substantially varied depending on the detergent structural variation, allowing us to explore detergent structure-property-efficacy relationships. The 1,3,5-triazine-based detergents introduced here have significant potential for membrane protein study as a consequence of their structural diversity and universal stabilization efficacy for several membrane proteins.</P> [FIG OMISSION]</BR>