4.Effect of Phosphorylation on Peptidyl-Prolyl Imide Bond cis/trans Isomerization of Peptides With Xaa-Pro Motif
Zhentai ZHU ; Ming SUN ; Yanting GUO ; Yanmei LI
Progress in Biochemistry and Biophysics 2007;34(6):585-594
The peptidyl-prolyl imide bond cis/trans isomerization of Xaa-Pro motif in the peptide and protein plays an important role to influence their conformation and function. Here, a series of model peptides including phosphorylated and its unphosphorylated counterparts were designed and synthesized. Preliminary 1H NMR experiments and molecular dynamics (MD) simulation were used to analyze the peptidyl-prolyl cis/trans imide bond isomerization. The data indicated that the side-chain O-phosphorylation of the Xaa residues preceding proline affected evidently the isomerization and thereby regulated the peptides conformations. The charges of the phosphate moiety as well as their steric effects might be the driving force for the conformational changes of these phosphopeptides.Moreover, the obtained most stable multiple configurations and their statistic cis/trans concentration distribution in MD simulation were basically consistent with the NMR experiments, which demonstrated that phosphorylation increased the cis conformation of the peptide and the maximum cis ratio is given while the phosphate group has no negative charge.
7.Progress on Biotechnological Production of Butyric Acid
Ming-Rong DENG ; Jun GUO ; Hong-Hui ZHU ;
China Biotechnology 2006;0(03):-
Butyric acid can be used to produce cellulose butyrate fiber and ester derivatives,and to be applied in foodstuffs and perfume industries.Recent researches have found that butyric acid is a preferred carbon source for colonic epithelial cells,and can inhibit histone deacetylase,showing great anticancer potentials.With more and more functions of butyric acid being found and applied in bio-related fields,and with consumer's growing preference to bioproducts,biotechnological production of butyric acid will receive more competence than petroleum-based chemical synthesis.Low product concentration and poor selectivity are presently the main restricting factors.Workers have made considerable progress on more cheep carbon sources,optimization of fermentation process,simplifying downstream processing,and genetic engineering of producing strains.Any achievement on these aspects in the future can contribute to put fermentation of butyric acid into industry.
8.Purification and Characterization of Laccase from Monodictys asperospera (Cooke & Massee) Ellis
Yi-Ning WANG ; Guo-Zhu ZHAO ; Yue-Ming ZHAO ; Xiao-Liang DI ; Xiang-Ming XIE ;
Microbiology 2008;0(11):-
A new wood-degrading fungus Monodictys asperospera(Cooke & Massee) Ellis with a high level of laccase production was chosen to study.This laccase was purified by ammonium sulfate precipitation,DEAE-cellulose and sephacryl S-300.Purification of about 8.1 fold was achieved with an overall yield of 5.7%.Its molecular weight was estimated to be about 77 kD.The optimum temperature and pH of the lac-case activity were 55?C and 6.0,respectively.Kinetic studies of the laccase showed that the Km and the Vmax for using syringaldazine as substrate was 0.163 mmol/L and 0.194 mmol/(L.min),respectively.The carbo-hydrate content was 18.14%.In addition,it was found that laccase activity was significantly inhibited by Cu2+.
9.Microsurgery for sellar region lesions via frontolateral approach
Bao-Guo LIU ; Li-Ming HE ; Gang XIAO ; Ming GUO ; Biao ZHU
Chinese Journal of Neuromedicine 2012;11(6):633-635
Objective To investigate the feasibility and effect of frontolateral approach in microsurgical treatment of sellar region lesions. Methods Twenty-eighty patients with sellar region lesions,admitted to our hospital from January 2009 to December 2011,were treated with microsurgery via frontolateral approach; a retrospective analysis of their clinical data was conducted. In these 28 patients,8 had meningiomas ofsellar tuberculum and anterior clinoidal process,5 pituitary tumors,3 craniopharyngiomas, 1 cholesteatoma, 6 anterior communicafing artery aneurysms and 5 posterior communicating artery aneurysms. Results The total removal was achieved in 12 of the 17 patients with sellar region tumors,and subtotal removal in 5.Six patients with anterior communicating artery aneurysm and 5 with posterior communicating artery aneurysm were successfully clipped.No death or severely disabled case were noted. Conclusion The microsurgery via frontolateral approach can fully expose the sellar region lesions and proper treatment can be given, which is minimally invasive and enjoys satisfactory result.
10.Influence of reverse osmosis concentrate on physicochemical parameters of Sini decoction material system and their relevance.
Tang-Hui JIN ; Liu-Hong ZHANG ; Hua-Xu ZHU ; Li-Wei GUO ; Bo LI ; Ming-Ming LU
China Journal of Chinese Materia Medica 2014;39(8):1421-1425
OBJECTIVEBy studying the process of reverse osmosis system for traditional Chinese medicine materials physicochemical parameters affecting the osmotic pressure of its relevance, new compound system reverse osmosis process design methods were explored.
METHODThree concentrations materials for high, middle and low were dubbed with Sini decoction as a model drug, and pretreated by 50 thousand relative molecular weight cut-off ultrafiltration membrane. The viscosity, turbidity, conductivity, salinity, TDS, pH value and osmotic pressure of each sample were determined after the reverse osmosis to study the physical and chemical parameters between their respective correlations with the osmotic pressure, and characterized by HPLC chromatograms showing changes before and after the main chemical composition of samples of reverse osmosis.
RESULTConductivity-osmotic pressure, salinity-osmotic pressure of the linear correlation coefficient, TDS-osmotic pressure between the three sets of parameters were 0.963 8, 0.932 7, 0.973 7, respectively. Reverse osmosis concentrate and its characteristic spectrum ultrafiltrate HPLC similarity were up to 0. 968 or more, except the low concentrations.
CONCLUSIONThere is a significant correlation between the three physicochemical parameters (conductivity, salinity, TDS) and osmotic pressure of each sample system, and there is also significant linear correlation between salinity, conductivity, TDS. The original chemical composition of Sini decoction material concentrate was completely remained after the process of reverse osmosis.
Chemical Phenomena ; Chemistry, Pharmaceutical ; methods ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; chemistry ; Molecular Weight ; Osmotic Pressure ; Surface Properties ; Viscosity