Structure-Antibacterial Activity Relationship for 9-O,9′-O-Demethyl (+)-virgatusin

The relationship between the antibacterial activity and structure of 9-O,9′-O-demethyl (+)-virgatusin (Virg 3) was examined. The conversion of hydroxy groups on the 9 and 9′ positions to amino groups increased the activity. It was found that the 3′-methoxy group was more important for higher activity than the 4′-methoxy group on the 7′-phenyl group, and that the 3,4-methylenedioxy group on the 7-phenyl group was necessary for activity.     

Antifungal Activity of Tetra-Substituted Tetrahydrofuran Lignan, (−)-Virgatusin,and Its Structure-Activity Relationship

Antifungal activities of the optically pure (>99%ee) (?)- and (+)-virgatusin, a tetra-substituted tetrahydrofuran lignan, were tested. (?)-Virgatusin, which is a natural product, showed highest antifungal activity against Colletotrichum lagenarium. Research on its structure-activity relationship was also performed. It was shown that two methoxy groups on 9 and 9′ positions and a 3,4-methylenedioxyphenyl group on the 7 position of virgatusin were essential for high fungal growth inhibition. The part on 7′-phenyl group was not essential for activity. The 7′-(4-methoxyphenyl) derivative showed higher activity than that of (?)-virgatusin.     

亲和层析技术在生物科学中的应用及发展

近几十年来,亲和层析技术发展十分迅速,广泛应用于生物分子(如结合蛋白、酶、抑制剂、抗原、抗体、激素、激素受体、糖蛋白、核酸及多糖类等)及组织(如细胞、细胞器、病毒等)的分离和纯化,是蛋白质组学研究中重要的技术之一.介绍了亲和层析的基本类型及配体合成的研究进展,概述了亲和层析技术在蛋白质组学以及在其他方面的应用和发展动态.     

Triolein,as a Phagostimulant for Albino Rat

Protaminobacter ruber, having a firm cell wall, could be lyzed by treatment with glycine or penicillin. Among amino acids tested, only glycine showed an excellent effect for the lysis. The optimal amount and time of addition of glycine for the lysis were 6 mg per ml culture and 4 to 5 hr after initiation of the cultivation, respectively. Aeration was necessary for the lysis as well as the growth of P. ruber. Morphological changes during the lysis of the bacterium were confirmed by electron microscopy. Proteins and (δ-ALA dehydratase were excreted into the medium with the progress of lysis.     

Affinity Chromatography of Cholinergic Receptor Proteins

Abstract

Cholinergic binding proteins were purified from torpedo electric organ. The preparation comprises: solubilization by non-ionic detergents followed by unspecific prepurification. For prepurification the double reversed technique proved to be very useful. Finally we applied affinity chromatography. For the affinity purification we used resins with chemically well defined small ligand groups from the depolarizing type (carbachol- and decamethonium-analogue), and from the stabilizing type (gallamine amide amine). The purified receptor proteins from all three resins showed different subunit compositions and different properties of α-bungarotoxin binding.     

金属螯合亲和层析的应用研究进展

金属螯合亲和层析是近30年来出现的一种新型的分离纯化技术,它以配基简单、吸附量大、分离条件温和、通用性强等特点,逐渐成为分离纯化蛋白质等生物工程产品最有效的技术之一.其在蛋白质、酶和核苷酸纯化以及蛋白质分析等方面具有广泛的应用.而随着研究的进一步深入,其新应用也越来越广泛的被发现.     

Affinity Chromatography of Acid Proteases on SPI Coupled to PAB-Cellulose

Tastes of Leu-Lys-Tyr (LKY) analogues, a series of potent angiotensin I converting enzyme (ACE) inhibitory peptides were evaluated. Some of these analogues were found to be sweet, such as Val–Lys-Tyr and Ala-Orn-Tyr. Furthermore, the structural requirements for sweetness or decreasing the bitterness were investigated by considerations of the structure–taste relationship with LKY analogues.     

Application of Affinity Adsorption Chromatography for the Purification of Human Brain Specific Antibodies

WE have found a glycoprotein in the human brain which is brain specific on immunological criteria¹. Ontogenetically, this glycoprotein appears at the stage of premyelination glia. The amount increases in parallel with the development of the human brain and probably remains at a constant level in the adult brain². We found it in normal and pathological human brain, predominantly in the white matter and in trace quantities in the grey matter (putamen, n. caudatus)². It is not present in the peripheral nerves, but was found in the n. opticus. This component is almost identical with the brain specific protein of Macacus rhesus and semi-identical with the brain-specific protein of rats².     

First Stereoselective Synthesis of meso-Secoisolariciresinol and Comparison of Its Biological Activity with (+) and (−)-Secoisolariciresinol

The first stereoselective synthesis of meso-secoisolariciresinol is reported. A comparison of the cytotoxic and immunosuppressive activity between meso-secoisolariciresinol and optically active secoisolariciresinols was similarly performed for the first time. Both enantiomers of secoisolariciresinol accelerated IgM production, although meso-secoisolariciresinol did not affect IgM production. Only meso-secoisolariciresinol showed cytotoxic activity.     

电泳亲和色谱技术分离蛋白质

亲和色谱利用亲和配体与目标组分间的特异性结合作用实现对目标组分的纯化,该分离方法分辨率高,在生物物质的分析和分离领域得到日益广泛的应用［１］。亲和色谱在分离过程每一步操作中,液相主体中的溶质分子必须经过一系列扩散过程才能进入到固定相颗粒孔内完成吸附或...     

Purification of Adenine Phosphoribosyltransferase by Affinity Chromatography

The purine salvage pathway enzyme adenine phosphoribosyltransferase (AMP: pyrophosphate phosphoribosyltransferase EC 2.42.7) has been purified to greater than 85% homogeneity from crude rat liver 100,000 × g supernatant in one step by affinity chromatography. The enzyme binds to an AMP-agarose column and is eluted off the column by 1 mM 5-phosphori-bosyl pyrophosphate with a 50 to 80% recovery. Enzyme kinetics indicate that the mechanism of the specific elution is due to competition of the product AMP and substrate 5-phosphoribosyl pyrophosphate for the same site on the enzyme.     

Purification of NADH-Nitrate Reductase by Affinity Chromatography

Assimilatory nitrate reductase (NADH: nitrate oxidoreductase, EC 1.6.6.1) from Chlorella vulgaris has been purified to electrophoretic homogeneity with an overall yield of 60% by a procedure that utilizes blue dextran-agarose as an affinity column. Nitrate reductase binds to blue dextran and is not eluted in the presence of high ionic strength buffer but is rapidly eluted in the presence of μmolar concentrations of NADH.     

Nonexistence of Exo-cellobiohydrolase (CBH) in the Cellulase System of Trichoderma viride

Chemical modification of histidine residues in ricin E was studied with regard to saccharide binding. The analytical data indicate that 6 out of 7 histidine residues in ricin E are eventually modified with diethylpyrocarbonate (DEP) at pH 6.0 and 25°C in the absence of specific saccharides. Modification of histidine residues greatly decreased the cytoagglutinating activity of ricin E, and only 10% of the residual activity was found after modification of 6 histidine residues/mol. The data of affinity chromatography using lactamyl- and galactosamine-cellulofine columns suggest that modification of histidine residues does not have much effect on the binding ability at the low affinity saccharide-binding site of ricin E but abolishes the binding ability at the high affinity saccharide-binding site. In the presence of lactose, one histidine residue/mol was protected from the DEP modification with retention of a fairly high cytoagglutinating activity. Such a protective effect was also observed for specific saccharides such as galactose and A^-acetylgalactosamine, but not for glucose, a non-specific saccharide. On treatment with hydroxylamine, the modified ricin E restored 67 % of the cytoagglutinating activity. Based on these findings, it is suggested that in the high affinity saccharide- binding site of ricin E there exists one histidine residue responsible for saccharide binding.     

Purification of L-Isoleucyl t-rna Synthetase by Affinity Chromatography

L-Isoleucyl t-RNA synthetase was purified to 97% purity in a single step by affinity chromatography on a column carrying L-isoleucinyl 5′-adenylate as the insolubilized ligand. Recovery was 50–60%.     

Binding of ATP to Brain Glutamate Decarboxylase as Studied by Affinity Chromatography

Abstract: The interactions of two forms of porcine brain glutamate decarboxylase (β-GAD and γ-GAD) with the effector ATP were studied by affinity chromatography. A third form, γk-GAD, was only slightly retarded by the affinity matrix and was eluted in the buffer wash. The interaction of GAD with the ATP affinity matrix was qualitatively similar to its interaction with free ATP as reported in previous kinetic studies. The rank order of adenine nucleotides as eluting agents and affinity ligands was ATP > ADP > AMP. GAD was also eluted by its cofactor, pyridoxal 5'-phosphate, and this was enhanced by 1 mM P_i In contrast, a high concentration (140 mM) of P_i by itself was required to elute the enzyme. GAD remained active while bound to the affinity column and was eluted in the holoenzyme form by ATP, indicating that the affinity ligand did not bind in the active site and did not displace catalytically active cofactor from the enzyme.     

薄芝糖肽亲和层析纯化技术

目的研究硼配基亲和层析技术纯化薄芝糖肽的新方法.方法用乙酸铵缓冲液考察不同pH条件下加入不同浓度NaCl对薄芝糖肽吸附解吸的影响,找出静态最佳吸附解吸条件;依据Chase模型求出最大静态吸附容量、吸附常数以及动态吸附糖及蛋白的容量.结果在pH8.2、NaCl浓度加至0.15mol/L条件下薄芝糖肽的吸附量达到最大,因此为最佳吸附解吸条件;在此条件下的最大静态吸附容量qm=55.57mg/g湿基,吸附常数Kd=5.312g/L;动态吸附多糖容量为43.1mg/g湿基,动态吸附蛋白容量为10.3mg/g湿基.结论该系统使用的亲和层析能有效地分离纯化薄芝糖肽.     

Purification of Canine Plasma Renin by Affinity Chromatography

An affinity column for the purification of canine plasma renin was prepared using goat anti-renin (dog kidney) γG globulins. The antiserum was prepared against a purified kidney renin preparation. The anti-renin globulins were coupled to cyanogen bromide-activated Sepharose. Using the anti-renin globulin-coupled Sepha-rose as an immuno-adsorbant, a method was devised allowing purification of plasma renin to a 1, 000-fold purity.     

Purification of Cathepsin D by Ah-Sepharose Affinity Chromatography

A rapid and reliable method for coupling the protease in-hibitor pepstatin to AH-Sepharose 4B was developed. The matrix prepared was used to purify cathepsin D from rat liver. The enzyme was eluted in one fraction and proved to be pure by gel electrophoresis, two types of ion exchange chromatography, molecular sieve chromatography, and immunologically homogenous by Immunoelectrophoresis. This method is more rapid and gives a higher yield than previous techniques. The possibility to use this technique for the purification of other enzymes inhibitable by pepstatin should be considered.     

IgE-Suppressive Activity of (−)-Matairesinol and Its Structure-Activity Relationship

The IgE-suppressive activity of (?)-matairesinol is demonstrated, and the structure-activity relationship of (?)-matairesinol clarified. 3′,4-Dihydroxy-3,4′-dimethoxylignano-9,9′-lactone showed higher IgE-suppressive activity than (?)-matairesinol without any cytotoxic activity. Some derivatives bearing a longer and more bulky alkoxy group at the 3 or 4 position showed IgE-accelerative activity.     

1,3,5,7-Tetramethyldecyl Formate,Lardolure: Aggregation Pheromone of the Acarid Mite,Lardoglyphus konoi (Sasa et Asanuma) (Acarina: Acaridae)

From an acarid mite, Lardoglyphus konoi (Sasa et Asanuma) (Acarina: Acaridae), with its culture medium, an aggregation pheromone was isolated. The structure of the pheromone was determined as 1,3,5,7-tetramethyldecyl formate and identified by 11 steps of organic synthesis. The absolute configuration of C₁ was assigned as R. The compound has been assigned the trivial name lardolure. The synthesized diastereomeric mixture of racemates showed one-tenth of the activity of the natural pheromone against the test mite, Carpoglyphus lactis.