Comparison of the Contributions of Tetrahydrofurfuryl Alcohol and PEG to a-Chymotrypsin Renaturation with High Performance Hydrophobic Interaction Chromatography

Theinvestigationofproteinrenaturation,orrefoldinghasbecomeaveryhotpointinbothliquidchromatography(LC)andlifesciencefields.Besidesusualdilutionanddialysismethods,manynewmethodsconcernproteinrenaturationhavebeenpresented,suchasreversemicelles1,chaperones2,polyethyleneglycol(PEG)3,surfactant4andantibodies5etc.Oneoftheauthorssuggestedhighperformancehydrophobicinter-actionchromatography(HPHIC)tobeanewtoolforproteinrenaturation6.Areviewonproteinrenaturationwithliquidchromatography(LC)wasrecentl…     

Study on the Synthesis of Metabolite of Clausenamide （CM1）

(-) Clausenamide (1) showed strong nootropic action, while its (+) antipode had no such an action. The content of CM1(2) in the metabolites of (-)1 is much higher than that of (+)11. For comparing the nootropic activity of enantiomers, (+) and (-) CM1 were synthesized. CM1 is the hydroxylated product of the N-methyl group of clausenamide. Oxidation of the C3-OH and C6-OH protected clausenamide to introduce the hydroxyl group into the methyl was tried but unsuccessful. Then de novo s…     

Kinetic Studies on Na^＋／K^＋-ATPase by Using Thermokinetic Method

Introduction Na+/K+-ATPase (ATP phosphohydrolase, EC 3.6.1.3) is an important membrane-bound enzyme. It catalyzes the hydrolysis of ATP, and uses the energy from the reaction to maintain the low internal sodium and high internal potassium concentrations characteristic of most animal cells. So it has been convincingly identified with the sodium pump. The kinetics of Na+/K+-ATPase has been extensively researched by classical methods such as spectrophotometry, 32-ATP isotopic determinatio…     

Studies on Hepatocyte-Targeting Magnetic Resonance Imaging Macromolecular Contrast Media

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STUDY ON THE SYNTHESIS AND PHYSICOCHEMICAL PROPERTIES OF SUCROSE POLYESTER

1. INTRODUCTIONSucrose polyester (SPE) is neither metabolized nor absorbed, it makes no caloric contribution to the diet. Excessive dietary fat intake is associated with increasing risk of obesity, high blood cholesterol, hypertension, coronary heart disease and some types of cancer. At present, fat substitutes are fashionable all over the world. SPE is a new functional fat substitute, which is similar to ordinary oils in physical and chemical properties. In a word, the research and dev…     

Electrochemical Enzyme Immunoassay of Tumor Marker CA15-3 with Capillary Electrophoresis

CA15-3 is a circulating antigen that is relatively specific for human breast tissue. CA15-3 is significantly more sensitive than carcinoembryonic antigen in the evaluation of patients with both primary and metastatic breast cancer. CA15-3 levels are often measured by using radioimmunoassay and enzyme immunoassay (EIA) in clinic. These methods are carried out manually. Tedious processes, slow reaction, poor reproducibility are their major problems. Capillary electrophoretic immunoassay …     

Positional and Quantitative Characterization of the Hydroxyethyl Groups in Hydroxyethyl Starch by GC/MS or NMR

Hydroxyethyl starches (HES) have been used medically as plasma volume expanders. They are composed of a starch backbone and substituted hydroxyethyl groups. The backbone is ?(1,4)-glycosidic-linked anhydroglucose units, which has branches formed by ?(1,6)-glycosidic bonds. Hydroxyethylation can take place at the C-2, C-3 and C-6 sites of the glucose rings, as well as at the hydroxyl groups of the substituted hydroxyethyl groups. Variation of the position and quantity of the substituted …     

Thermokinetic Study on the Reversible Competitive Inhibition of Bovine Liver Arginase

Introduction Arginase (EC 3.5.3.1) is a widespread and very im-portant enzyme in mammals, which specifically cata-lyzes the hydrolysis of L-arginine to urea and the non-protein amino acid L-ornithine, a key step in the urea cycle.1 Urea is the principal metabolite for disposal of nitrogen as a neutral and nontoxic waste product formed during amino acid metabolism in mammals. L-ornithine serves as a biosynthetic precursor to L-proline and the polyamines such as putrescine, sper-mine (in eucar…     

Study on the Surface Photovoltage and Fluorescence Properties of N, N-Bis(4-aminopheny)-1, 4 quinonenediimine Doped with H_4SiW_(12)O_(40)

Polyaniline, especially its acid-dopping composite material, is a kind of important photoelectric material due to its potential application in many fields1~3. However, it seems to be a problem that the polymers exhibit several deficiencies, including chemical and structural imperfections as a result of mislinkage, saturated sites, molecular weight distribution, the presence of the end groups and conformation defects. All of these defects affect the device efficiency and make it difficult to …     

Inhibitory Effect of Anti-HER-2 Anti-CD3 Bi-specific Antibody on the Growth of Gastric Carcinoma

Introduction Gastriccancerisoneofthemostcommonlyen counteredmalignantdiseasesworldwide,especiallyin AsiaandAfrica[1].Thecombinationofoperation,chemotherapyandradiotherapyisusedfortreatinggas triccarcinoma.However,the5yearsurvivalrateof patientsofgastricca…