扇贝糖胺聚糖的琼脂糖凝胶电脉分析

从海湾扇贝边中提取分离出扇贝糖胺聚糖,其红外光谱与肝素类似。将扇贝糖胺聚糖制品在0.06mol/L,pH8.6巴比妥缓冲系统中进行琼脂糖凝胶电泳分析,发现其电泳图谱显示单一区带;与糖胺聚糖标准品——肝素、透明质酸和6-硫酸软骨素对照,其电泳相对迁移率与肝素量为接近。     

扇贝糖胺聚糖的琼脂糖凝胶电泳分析

从海湾扇贝边中提取分离出扇贝糖胺聚糖，其红外光谱与肝素类似。将扇贝糖胺聚糖制品在０．０６ｍｏｌ／Ｌ，ｐＨ８．６巴绥缓冲系统中进行琼脂糖凝胶电泳分析，发现其电泳图谱显示单一区带。与糖胺聚糖标准品－肝素，透明质酸和６－硫酸软骨素对照，其电泳相对迁移率和肝素最为接近。     

冠心舒对大鼠实验性心肌坏死的保护作用

<正> 冠心舒是从猪十二指肠提取的酸性粘多糖类药物。常见的酸性粘多糖有肝素、硫酸软骨素 A、硫酸皮肤素、硫酸软骨素 C、透明质酸和硫酸类肝素等,其中肝素、硫酸软骨素 A、硫酸类肝素(如 Asclerol,Ateroid)已作为抗凝血药,降血脂药,抗动脉粥样硬化药应用于临床。1976年 Saliba 等结扎狗冠状动脉造成急     

透明质酸与临床疾病诊断的研究进展

糖类分子以聚糖及糖蛋白等形式在细胞表面构成一层与细胞生理功能密切相关的糖衣.其中糖胺聚糖(glycominoglycan),既往又被称为粘多糖(mucopolysaccharide),是构成细胞表面糖衣的主要成分.已糖、胺和己糖醛酸或非含氮单以糖苷键相连构成双糖基本单位,而酸性糖胺聚糖即由许多重复的双糖基本单位组成.该重复双糖的基本结构是GlcUA-β1,3-GlcNAc1,4,即由葡萄糖醛酸和N-乙酸葡萄糖胺以β13键连接而成.根据这种重复双糖结合骨架结构构成的不同,可将糖胺聚糖分为4类:透明质酸,硫酸软骨素,硫酸角质素和硫酸乙酰肝素及肝素.其中,透明质酸(Hyaluronic acid,HA)由25,000个重复双糖组成,是结构最简单、分子量最小的一类糖胺聚糖,但其分子量亦达1,000万[1].     

蛋白聚糖与临床

蛋白聚糖(PGs)的研究始于19世纪末,最早从软骨组织中分离获得硫酸软骨素。20世纪50年代,人们才逐步认识到糖胺聚糖链(GAG)是与一些蛋白成分共价相连的。由于PGs是非常复杂的生物大分子,直到60～70年代,完整的PGs分子才得以分离纯化。随着分子生物学研究技术的飞速发展及向...     

3种鱼鳃中糖胺聚糖的分离纯化及细微结构比较分析

目的 从狭鳕 (Alaska pollack)、褐牙鲆 (Bastard halibut) 和真鲷 (Red seabream) 三种鱼鳃中提取分离糖胺聚糖并对其细微结构进行比较分析。方法 利用酶法降解并以阴离子交换色谱法分离纯化糖胺聚糖,通过单糖组成和醋酸纤维素薄膜电泳对其种类进行鉴别,采用高效液相色谱法对其相对分子量和二糖组成进行比较分析,最后利用核磁共振波谱法 (₁H-NMR) 对其结构进行表征。结果 从3种鱼鳃组织中提取分离得到54种多糖,其中18种是电荷和分子量均一的糖胺聚糖,它们集中在0.8 mol?L_-1 NaCl洗脱部分 (P4) 和1.0 mol?L_-1 NaCl洗脱部分 (P5),占多糖总量的17.4～58.4%;P4主要为硫酸软骨素C (CSC),P5主要为硫酸软骨素A (CSA) 和杂合硫酸软骨素 (HyCS),尤其,与牛气管来源CSA比较,HyCS的4S/6S比和电荷密度均较大。结论 狭鳕、褐牙鲆和真鲷鱼鳃组织中的糖胺聚糖主要为CSA、CSC和HyCS。     

马氏珠母贝糖胺聚糖体外抑制HL-60肿瘤细胞作用的初步观察

目的探讨马氏珠母贝全脏器为原料提取的糖胺聚糖抗肿瘤的活性。方法用台盼蓝染色作活细胞计数,计算出药物对细胞的生长抑制率,观察马氏珠母贝糖胺聚糖对人白血病细胞株HL-60细胞的影响。结果马氏珠母贝糖胺聚糖在0.031~2.0g.L-1的不同浓度时,对HL-60细胞都有不同的抑制作用。且与5-氟脲嘧啶(5-Fu)合用,具有协同作用。结论马氏珠母贝全脏器提取物糖胺聚糖对HL-60细胞具有明显的抑制作用。     

色谱法分析粘多糖

<正> Meyer曾提出把含有氨基己糖(即己糖胺)的多糖,叫做粘多糖(mucopolysaccha-rides),也叫做酸性粘多糖(acidmucopoly-saccharides)。如:硫酸皮肤素(dermatansulfate)、透明质酸(Hyaluronic acid)、硫酸软骨素(chondroitin sulfate)、肝素(hep-arin)、硫酸乙酰肝素(heparan sulfate)及糖醛酸(uronic acid)等。分析粘多糖的方法很多,在前文中,曾对肝素及硫酸软骨素的分析方法,作过介绍,现将文献中有关粘多糖的色谱分析方法,简要地阐述如下。     

马氏珠母贝糖胺聚糖体外抑制HL-60肿瘤细胞作用的初步观察

目的探讨马氏珠母贝全脏器为原料提取的糖胺聚糖抗肿瘤的活性。方法用台盼蓝染色作活细胞计数,计算出药物对细胞的生长抑制率,观察马氏珠母贝糖胺聚糖对人白血病细胞株HL-60细胞的影响。结果马氏珠母贝糖胺聚糖在0.031～2.0g·L^-1的不同浓度时,对HL-60细胞都有不同的抑制作用。且与5-氟脲嘧啶(5-Fu)合用,具有协同作用。结论马氏珠母贝全脏器提取物糖胺聚糖对HL-60细胞具有明显的抑制作用。     

糖胺聚糖和蛋白聚糖对神经细胞及中枢神经系统的调节作用

糖胺聚糖及其与蛋白组成的蛋白聚糖属于体内糖复合物大分子。此文综述了它们对神经生长和中枢神经系统的调节作用。发现硫酸乙酰肝素、硫酸软骨素、硫酸角质素、肝素和硫酸皮肤素等糖胺聚糖或蛋白聚糖对神经细胞生长能起到一定的调节作用,这对揭示它们在脑科学的生物学功能以及开发神经系统药物有着重大的意义。     

Experimental and clinical pharmacology of glycosaminoglycans (GAGs)

The experimental and clinical pharmacology of glycosaminoglycans (GAGs) is discussed, including that of heparin and related compounds, hyaluronic acid and chondroitin sulfates.     

The isolation and characterization of glycosaminoglycans in normal human serum

The optimization of conditions for the isolation and characterization of human serum glycosaminoglycans (GAG) is described, together with studies of the accuracy and reproducibility of the method. The principle of the method is proteolytic digestion of serum using papain followed by precipitation of GAGs from the digested sample with cetyl pyridinium chloride (CPC). The uronic acid level and electrophoretic separations can be obtained from a 5 ml serum sample. The mean CPC-precipitable uronic acid level in pooled normal serum was 10.8 mg l(-1) serum. Using enzymatic and chemical analysis the major serum GAG was shown to be chondroitin sulphate (CS). Two distinct electrophoretic fractions were identified both consisting of CS but differing in their degree of sulphation. Dermatan sulphate, heparan sulphate and hyaluronic acid were not detected.     

Therapeutic applications of glycosaminoglycans

Complex polysaccharides, hyaluronic acid or hyaluronan (HA), keratan sulfate (KS), chondroitin sulfates (CSs) and heparin (Hep)/heparan sulfate (HS), are a class of ubiquitous molecules exhibiting a wide range of biological functions. They are widely distributed as glycosaminoglycans (GAGs) sidechains of proteoglycans (PGs) in the extracellular matrix and at cellular level. The recent emergence of improved enzymatic and analytical tools for the study of these complex sugars has produced a virtual explosion in the field of glycomics. In particular, the study of the GAG family of polysaccharides has shed considerable light on the way in which specific carbohydrate structures modulate cellular phenotypes. In addition to the well-known therapeutic applications of some of these macromolecules, such as HA and derivatives as structure modifying molecules and possessing gel-like properties able to provide functional support for tissues, Hep as an anticoagulant and antithrombotic drug and CS in the treatment of osteoarthritis (OA), this increased understanding of GAG structure-function relationship has led to the discovery of novel pharmaceuticals for the possible treatment of serious diseases, such as cancer. In this paper, the structure and the therapeutic applications of several complex natural polysaccharides, including HA, CS/DS, Hep and their derivatives, are presented and discussed also in the light of the many questions still left unanswered, such as improved preparation and GAG-based drugs with improved properties and new possible therapeutic applications.     

Thermodynamic analysis of binding between drugs and glycosaminoglycans by isothermal titration calorimetry and fluorescence spectroscopy.

The thermodynamics of the interaction of positively charged drug molecules with negatively charged glycosaminoglycans (GAGs) is investigated by isothermal titration calorimetry (ITC) and fluorescence spectroscopy. The drugs considered are propranolol hydrochloride, tacrine, and aminacrine, and the polymers used as model GAGs are dextran sulfate, chondroitin sulfate, and hyaluronic acid. The ITC results show that the interaction between drugs and GAGs is via direct binding and that GAGs bind to drugs at one set of sites. Large negative values of heat capacity change (DeltaC(p)) are observed upon binding of GAGs to drugs. Such negative DeltaC(p) is not expected for purely electrostatic interactions and suggests that hydrophobic and other interactions may be also involved in the binding process. These results are corroborated by fluorescence spectroscopy measurements, which show that specific drug/GAG complex formation is accompanied by a clear enhancement of the fluorescence intensity. The results highlight the importance of the formation of drug/GAG complexes as a primary step for the drug delivery process into cell membranes. It is concluded that the interactions are dependent on the nature of both GAG and drug and this is a fact to be taken into account when new drugs are designed.     

One-dimensional cellulose acetate plate electrophoresis—A feasible method for analysis of dermatan sulfate and other glycosaminoglycan impurities in pharmaceutical heparin

A cellulose acetate plate electrophoresis method for analysis of pharmaceutical heparin and its potential glycosaminoglycan impurities, e.g. dermatan sulfate, chondroitin sulfate and oversulfated chondroitin sulfate, is presented. Heparin is chemically degraded by application of nitrous acid and residual glycosaminoglycans are electrophoretically separated thereafter. After staining using Alcian blue 8GS, these glycosaminoglycan impurities can be quantified by means of comparison to a dermatan sulfate standard. Results of a validation study of this analytical method are shown, demonstrating its feasibility for routine use in analytical quality control labs under GMP conditions.     

The role of histamine in wound healing I. The effect of high doses of histamine on collagen and glycosoaminoglycan content in wounds.

The effect of high doses of histamine (Hi) on collagen and glycosoaminoglycan (GAG) content in skin wounds of rats was studied on days 1, 3, 5, 10 and 14 after wounding. Injection of high doses of Hi into the wounded area inhibited colagen production, collagen polymerization and GAG synthesis; levels of chondroitin sulphates (chondroitin-4,6-sulphate and dermatan sulphate) and hyaluronic acid were decreased.     

Structural and conformational aspects of the anticoagulant and anti-thrombotic activity of heparin and dermatan sulfate

Heparin and other iduronic acid-containing glycosaminoglycans (GAG) such as dermatan sulfate exert their anticoagulant properties primarily by accelerating the rate of inhibition of the natural protease inhibitors antithrombin III (AT, which inhibits both factor Xa and thrombin) and heparin cofactor II (HCII, which selectively inhibits thrombin). Although AT and HCII are structural homologs, only heparin binds to AT, and HCII has different binding sites for heparin and dermatan sulfate. Whereas the binding site of heparin for AT is a unique pentasaccharide sequence contained in only about one third of the chains of this GAG, HCII-binding sequences of heparin and dermatan sulfate are less specific and contained in practically all the GAG chains. Protein binding and associated biological activities of heparin and dermatan sulfate are modulated by the "plasticity" of their iduronic acid residues due to the availability of up to three equienergetic conformation among which the protein selects the one favouring the most stable complex. Glycol-splitting of nonsulfated uronic acid residues, a device for generating flexible joints along the GAG chains, has different effects on different binding domains. Whereas it inactivates the binding site for AT causing a drop of the anticoagulant activity, it enhances the HCII-associated activity of both heparin and dermatan sulfate.     

Biosynthetic mechanism of the bioactive sulfated glycosaminoglycans

Sulfated glycosaminoglycans including heparin/heparan sulfate and chondroitin/dermatan sulfate have been implicated in numerous pathophysiological phenomena in vertebrates and invertebrates. The critical roles of glycosaminoglycans, especially heparan sulfate, in developmental processes involving the signaling of morphogens such as Wingless and Hedgehog proteins, as well as of fibroblast growth factor, in Drosophila have recently become evident. In biosynthesis, the tetrasaccharide sequence (GlcA-Gal-Gal-Xyl-), designated the protein linkage region, is first built on a specific Ser residue at the glycosaminoglycan attachment site of a core protein. A heparin/heparan sulfate chain is then polymerized on this fragment by alternate additions of N-acetylglucosamine and glucuronic acid (GlcA) through the actions of glycosyltransferases with overlapping specificity encoded by the tumor suppressor EXT family genes. In contrast, a chondroitin/dermatan sulfate chain is synthesized on the linkage region by alternate additions of N-acetylgalactosamine and GlcA through the actions of glycosyltransferases, designated chondroitin synthases. Recent studies have achieved purification of a few and molecular cloning of all of the glycosyltransferases responsible for these reactions and have revealed the bifunctional nature of a few of these enzymes. The availability of the cDNA probes has provided several important clues to help solve the molecular mechanisms of the biosynthetic sorting of heparin/heparan sulfate and chondroitin/dermatan sulfate chains, as well as of the chain elongation and polymerization of these glycosaminoglycans.     

INTERACTION OF THE THREE MAIN COMPONENTS OF CLUPEINE WITH GLYCOSAMINOGLYCANS

The interactions between each of the three main components of clupeine (Y_I, Y_II and Z) and the glycosaminoglycans chondroitin sulfate, heparin and hyaluronic acid were studied with circular dichroism spectroscopy. The induced dichroism is a measure of relative complex stability, which increases with the number of sulfate groups on the glycosaminoglycan. Measuring the induced dichroism as a function of mole ratio of disaccharide to arginine establishes the stoichiometry of the complexes. For a given glycosaminoglycan, the induced dichroism depends on the clupeine, increasing in the order Y_I < Y_II < Z.     

Characterization of total plasma glycosaminoglycan levels in healthy volunteers following oral administration of a novel antithrombotic odiparcil with aspirin or enoxaparin

Odiparcil is a novel, orally active beta-d-thioxyloside analog with antithrombotic activity associated with a reduced risk of adverse bleeding events. Its unique mechanism of action is postulated by means of an elevation in circulating endogenous chondroitin sulfate-related glycosaminoglycans (GAGs) levels. The purpose of these 2 separate clinical studies was to evaluate plasma GAG levels in healthy subjects administered odiparcil with either aspirin (ASA) or enoxaparin. Clinical plasma samples were processed and analyzed using validated HPLC bioassays that indirectly estimate GAG levels based on the simultaneous detection of the chondroitin disaccharide derivatives. The concomitant administration of odiparcil with or without ASA resulted in a significant elevation in GAG levels over baseline for both treatment groups. In the other clinical study, the concomitant administration of odiparcil with or without enoxaparin displayed significant increases in plasma DeltaDi-OS, DeltaDi-4S, and total disaccharide levels versus control group. Neither plasma GAG levels nor odiparcil plasma levels were correlated with a rise in hepatic transaminases, an adverse drug event observed in several subjects; and plasma odiparcil levels were indirectly correlated with plasma GAG levels. These clinical studies were proof of concept of preclinical rat studies indicating that chronic odiparcil treatment elevates endogenous GAG levels in human subjects.