Purification and Properties of Bacterial Chondroitinases and Chondrosulfatases

Role of glycosaminoglycans in calcium metabolism of human platelets

Changes in intracellular Ca2+, [Ca2+]i, were measured in control and chondroitin ABC lyase-pretreated platelets. [Ca2+]i was measured with the fluorescent calcium probe Quin2. Chondroitin ABC lyase removed chondroitin 4-sulfate from the platelet surface without inducing shape change or release of serotonin. Compared to similarly prepared controls, enzyme treated platelets showed an increase of [Ca2+]i in response to stimulation by various agonists at high (1 mM) extracellular Ca2+ concentration. At low Ca2+ in the medium (1 mM EGTA), such platelets responded to agonists with a decreased rise in [Ca2+]i compared to the controls. These studies indicate that selective removal of glycosaminoglycans may sensitize platelets to the action of platelet aggregating agents. In addition, glycosaminoglycans may have a calcium storage function.

Studies of chemical and biologic properties of a fraction of sulodexide, a heparin-like glycosaminoglycan

The chemical composition and biologic properties of a fraction (f) of Sulodexide, a heparin-like GAG, were studied and compared with those of two sulfated GAG preparations and heparin from intestinal mucosa. f-Sulodexide and the sulfated GAG preparations were fractionated on a Dowex-1Cl- column and subsequently on an antithrombin III affinity column. Low affinity and high affinity fractions had similar chemical composition and lipoprotein lipase releasing ability, but they varied in anticoagulant activity. Low affinity fractions from f-Sulodexide had negligible anticoagulant activity while high affinity fractions had one-half the activity of mucosal heparin. When compared to heparin, both fractions had one third amount of lipoprotein lipase releasing activity. The low anticoagulant activity of f-Sulodexide suggests a suitability for long-term use as an antiatherogenic agent.

Polysaccharide lyases

Polysaccharide lyases (or eliminases) are a class of enzymes (EC 4.2.2.-) that act to cleave certain activated glycosidic linkages present in acidic polysaccharides. These enzymes act through an eliminase mechanism, rather than through hydrolysis, resulting in unsaturated oligosaccharide products. Acidic polysaccharides are ubiquitous and so are the lyases that degrade them. This review article examines lyases that act on acidic polysaccharides of plant, animal, and microbial origin. These lyases are predominantly of microbial origin and come from a wide variety of both pathogenic and nonpathogenic bacteria and fungi. The lyases discussed include alginate lyase (EC 4.2.2.3), pectin lyase (EC 4.2.2.10), pectate lyase (EC 4.2.2.2), oligogalacturonide lyase (EC 4.2.2.6), exopolygalacturonate lyase (EC 4.2.2.9), chondroitin lyases (EC 4.2.2.4 and EC 4.2.2.5), hyaluronate lyase (EC 4.2.2.1), heparin lyase (EC 4.2.2.7), heparan lyase (EC 4.2.2.8), and other unclassified lyases. This review examines the sources, regulation, purification, and properties of these polysaccharide lyases.

Proteoglycans and hypertension. I. A biochemical and ultrastructural study of aorta glycosaminoglycans in spontaneously hypertensive rats

The extracellular matrix of blood vessel walls contains elastin, collagen, and proteoglycans, all of which can affect vascular resistance and, hence, blood pressure by virtue of their biomechanical properties. In the present study, we have begun to explore the possibility that proteoglycans may play a role in the pathophysiology of hypertension by analyzing, qualitatively and quantitatively, the polysaccharide components of proteoglycans from aorta of two normotensive rat strains, Wistar Kyoto (WKY) and Wistar rats, and from spontaneously hypertensive (SH) rats of the Okamoto strain. The total concentration of aorta glycosaminoglycans in the SH rat was 33% higher than in the WKY rat, due to a 164% increase in chondroitin 4- and 6-sulfate. The content of dermatan sulfate (DS), hyaluronic acid (HA), and heparan sulfate (HS) was similar in the two strains. The 4-wk-old SH rat also had an increase in chondroitin sulfate (CS) compared to the 4-wk-old WKY rat, without any change in DS, HA, or HS. The Wistar rat had approximately the same concentration of CS und DS in the aorta as the WKY rat, but HS und HA were reduced by 62 and 37%, respectively. The galactosaminoglycans (CS and DS) were heterogeneous on cellulose acetate electrophoresis and exhibited a different pattern for each of the three strains. Undersulfated CS accounted for 15% of the total CS in WKY aorta but was present in only trace amounts in the SH aorta; 2% of the CS from the Wistar aorta was undersulfated. In all three strains, DS was exclusively 4-sulfated, and the CS contained approximately equal amounts of 4- and 6-sulfated galactosamine residues. Ultrastructural studies demonstrated that the HS was localized in the subendothelial matrix and the pericellular region surrounding the medial smooth muscle cells. CS and DS were primarily associated with collagen in the media. In the SH rat aorta the subendothelial matrix was thicker, and there was a relative increase in the CS/DS in the smooth muscle cell pericellular matrix. We suggest that, if similar alterations in CS proteoglycans are present in the resistance vessels, these changes may contribute to the increased peripheral vascular resistance in the hypertensive animal.

The fate of homologous nasal septal cartilages in tympanoplasty

We have used homologous nasal septal cartilage for tympanoplasty for the last 8 years and obtained satisfactory results. In order to demonstrate the fate of homograft cartilage implanted into the middle ear, mucopolysaccharides have been studied by means of enzyme digestion. The matrix of normal septal cartilage was divided into three regions: 1) pericellular region; chondroitin sulfate B, 2) distal interstitial region; hyaluronic acid and chondroitin sulfates, 3) peripheral interstitial region; collagen. In preserved cartilage, chondroitin sulfate B was lacked out, but hyaluronic acid and collagen remained intact though the amount of mucopolysaccharides diminished slightly when compared with normal septal cartilage. Homograft cartilages evidenced depletion of mucopolysaccharides. Homograft cartilages should be used for the purposes mentioned, though not as material for columella, nor for reconstruction of large bone defect.

Structural differences of dermatan sulfates from different origins

The dermatan sulfates from hog, rat, rabbit, and beef liver, hog, rat, beef, and dog spleen, and hog skin were isolated and submitted to structural analysis. All of them migrated as single bands, close to the standard position for dermatan sulfate in agarose-gel electrophoresis. In polyacrylamide gel, however, each dermatan sulfate showed a characteristic electrophoretic migration-pattern: one, two, or three polydisperse bands, corresponding to different molecular weights, were obtained for the dermatan sulfates according to their origins. Chemical analysis showed that all of the dermatan sulfates here described are hybrid polymers composed of D-glucuronic and L-iduronic acid-containing disaccharide units. The relative position of these units in the polymer chains and the presence of 6-sulfated disaccharides were determined with the aid of chondroitinases B and AC from Flavobacterium heparinum. These studies show that each dermatan sulfate has a unique structure as regards the molecular weight, the presence of 6-sulfated disaccharide units, and also the relative amount and position of glucuronic and iduronic acid residues in the chains. These findings suggests a tissue- and species-specificity for the dermatan sulfates.

Basal lamina-associated heparan sulphate proteoglycan in the rat PNS: characterization and localization using monoclonal antibodies

Cultured rat Schwann cells produce a basal lamina (BL)-associated heparan sulphate proteoglycan (HSPG). The HSPG has an apparent molecular weight of greater than 450 kD, is sensitive to both heparinase and heparitinase and contains a core protein of approximately 400 kD. Two independently derived monoclonal antibodies, B3 and C17, recognize this HSPG. Using B3 and C17, we found that this HSPG, or immunologically related material, is present in BLs throughout the body and in a small number of connective tissue sites without a formed BL. In the PNS it is present in BLs of Schwann cell-axon units, in synaptic and extrasynaptic portions of muscle fibre BL, and in the BLs of satellite cells that ensheath neurons in sympathetic and sensory ganglia. This HSPG is not detectable in the neuropil of the brain and spinal cord. Neurons, Schwann cells and fibroblasts cultured alone do not assemble a BL or accumulate immunocytochemically detectable amounts of this HSPG, but it is present in BLs assembled in myotube and in Schwann cell-neuron cultures. Thus, this HSPG is a component of most, if not all, BLs in the PNS.

Glycosaminoglycans in the cartilage of the porcine heart as studied by light microscopic histochemical methods

Glycosaminoglycans involved in the cartilage of the porcine heart have been studied by means of light microscopic histochemical methods. The methods employed consisted of a series of staining procedures for the demonstration of acidic groupings of glycosaminoglycans. In addition, some of these procedures were employed in combination with chemical modification and enzyme digestion techniques. According to the results obtained, the cartilage of the porcine heart contained hyaluronic acid, chondroitin, chondroitin sulfate A and/or C and keratan sulfate. The effects of digestion with enzymes upon the histochemical reactions of the cartilage tissues indicated that hyaluronic acid exists as a glycoprotein link factor of proteoglycan subunits, forming proteoglycan aggregates in tissues.

Mast cells and tumour angiogenesis: the tumor-mediated release of an endothelial growth factor from mast cells

Exposure to tumour cells has previously been shown to induce mast cells to degranulate and release heparin. Isolated mast-cell granules were found to be mitogenic for endothelial cells in vitro. This effect was a property of mast-cell heparin, whose potency as a mitogen exceeded that of commercial heparins. The basis of this difference lay in the proteoglycan structure of the molecule. The release of heparin in mast-cell-tumour co-cultures was examined by both endothelial cell proliferation and isotopic techniques. The kinetics and mode of release are described. The results are discussed in relation to the role of the mast cell in angiogenesis assays and tumour neovascularization.

Lectin binding to elastic fibres and associated components during development of the human aorta

A panel of peroxidase-conjugated lectins was used to stain frozen sections of human foetal, neonatal, infant and adult aortae. Two main distinctive staining patterns were observed at the light microscope level, depending on the lectin employed. Lectins from Concanavalin A, Triticum vulgaris, Arachis hypogaea and Glycine max resulted in staining of the surfaces of aortic elastic lamellae and the interlamellar areas. With lectins from Dolichos biflorus and Bandeiraea simplicifolia staining was seen predominantly in the interlamellar areas. The findings indicate the presence of several different glycoconjugates at various sites within the aorta. In addition, there were alterations in the lectin binding affinities of the aortae that were dependent upon age. The findings are interpreted as indicating sequential changes in the composition of glycoprotein or proteoglycan moieties in the development of the human aorta.

Polydispersity of acidic glycosaminoglycan components in human liver and the changes at different stages in liver cirrhosis

The aim of this study was to characterize acidic glycosaminoglycan components in normal human liver and in alcoholic cirrhosis, and to determine whether the proportions of individual glycosaminoglycans change with advancing cirrhosis. Acidic glycosaminoglycans are components of extracellular matrices and consist of repeating disaccharides of hexosamine and hexuronic acid with molecular weights ranging from 5 X 10(3) to 5 X 10(4), except for hyaluronic acid, whose molecular weight ranges from 3 X 10(4) to 1.6 X 10(6). The acidic glycosaminoglycan components in normal liver and at different stages of liver cirrhosis were found to be polydisperse as to the molecular weight and the degree of sulfation. The increased content of glycosaminoglycans with advancing liver cirrhosis was related to those of heparan sulfate and dermatan sulfate components. Heparan sulfates were the most prominent components of smaller molecular weight fractions. In the normal state, moderate amounts of dermatan sulfate and the oversulfated isomer were present in intermediate molecular weight fractions, but increasing amounts of the components shifted to higher molecular weight fractions with advancing cirrhosis. A small amount of hyaluronic acid was found in higher molecular weight fractions and the amount increased at the initial stage as a reversible phenomenon. The possible roles of hepatic glycosaminoglycan components in the process of fibrosis are discussed.

The molecular weight-dependent distribution of urinary glycosaminoglycans in Werner's syndrome

The macromolecular AGAG in the urine of patients with Werner's syndrome were analyzed by enzymatic methods after digestion with chondroitinases and Streptomyces hyaluronidase. The molecular weight-dependent distribution of the urinary AGAG has been determined by gel filtration on a Sephadex G-100 column. The distribution of HA and HS was predominant in the macromolecular fractions. Chondroitin sulfate isomers were prominent in the low molecular weight fractions but the ratio of the 4-type to the 6-type increased with decreasing molecular weight. These observations indicated that Werner's syndrome is a metabolic disorder of the molecular weight-dependent AGAG composition.

Increase in glycosaminoglycan synthesis in familial hypercholesterolemic fibroblasts

The enzymes of biosynthesis are usually bound to membranes and require an undisturbed lipid environment for regulated activity. In familial hypercholesterolemia, this lipid environment is disturbed and there is a low cholesterol ester level in the cellular membranes that results from impaired processing of low density lipoprotein (LDL). Thus, altered activities of various synthesizing enzymes could be expected. In this study, we found that microsomal glucuronyltransferase activity was 3.4-fold higher in homozygous familial hypercholesterolemic skin fibroblasts (n = 5) than in normal fibroblasts (n = 8). The secretion rates of glycosaminoglycans in familial hypercholesterolemia were also higher and the incorporation of radiolabeled precursor into glycosaminoglycans was enhanced. In addition to the differences in total synthesis and secretion, we found an altered pattern of individual glycosaminoglycan species with respect to the carbohydrate backbone and a different degree of sulfation in familial hypercholesterolemia. Heparan sulfate with a high degree of sulfation was secreted at a particularly high rate by hypercholesterolemic fibroblasts. Although the affinity of this glycosaminoglycan for LDL is lower than that of dermatan sulfate, it might cause formation of enhanced LDL-glycosaminoglycan complex and induce the xanthomas and atheromas of familial hypercholesterolemia.

Cell-cell matrix interactions in induced lung injury. II. X-irradiation mediated changes in specific basal laminar glycosaminoglycans

The thoraces of male LAF1 mice were irradiated at doses of 5, 9, or 13 Gy. The animals were killed at times of 1 hr, 1 day, 1 wk, 4 wks, and 12 wks postirradiation (PI). The lungs were removed, enzymatically or detergent digested, fixed with ruthenium red for demonstration of anionic sites, and processed for electron microscopy. Untreated (0 Gy, 0 time) and sham irradiated control groups were also processed. Sections of lungs were examined and changes in alveolar basal laminar anionic sites were quantitated. Changes in three groups of glycosaminoglycans (GAGs) were identified: chondroitin 4 and 6 sulfate-dermatan sulfate, hyaluronate, and other GAGs (principally heparan sulfate). At 1 hr PI, all groups showed a marked decrease in site number over controls, which continued to 1 wk. By 4 wks there was a marked relative increase in heparan sulfate containing sites for doses of 13 Gy and a moderate increase for the other doses. At 12 wks the level of heparan sulfate was considerably above normal for doses of 13 Gy and just above normal for the other doses. Chondroitin-dermatan sulfate had recovered by 12 wks for doses of 13 Gy, but was still subnormal for other doses; however, hyaluronate-containing sites recovered only slightly by 12 wks. The implications for this change on basal laminar permeability and the induction of fibrosis are discussed.

Immunoenzymoassay of the hyaluronic acid-hyaluronectin interaction: application to the detection of hyaluronic acid in serum of normal subjects and cancer patients

The binding of a hyaluronic acid-binding glycoprotein, hyaluronectin (HN), isolated from human brain, to hyaluronic acid (HA) was investigated with the enzyme-linked immunosorbent assay technique using plastic microtest plates coated with a 50 mg/liter solution of HA in 0.1 M bicarbonate. Optimum conditions for HN binding to HA were in 0.2 M NaCl buffered with 0.1 M sodium phosphate at pH 7. An assay for HA in solution was set up exploiting the fact that HN binding could be inhibited by soluble HA. HA was preincubated for 1 h in a test tube with a 30-ng/ml HN solution (v/v) in the buffer containing 0.1% bovine serum albumin. Incubation on HA-coated microtest plate lasted 4 h and maximum sensitivity was achieved when incubation was carried out at 4 degrees C. HN bound to the plate was revealed by means of alkaline phosphatase-conjugated anti-HN antibodies. The test was used to measure HA inhibitory activity after depolymerization by ferrous ions. No difference was found between inhibitory activity or smaller fragments and that of high-molecular-weight HA. The assay was applied to determination of HA in sera. Specificity was demonstrated by Streptomyces hyaluronidase digestion of reactive material in sera. Other glycosaminoglycans did not interfere with the assay. Recovery of HA was good and intra- and interassay variation coefficients were 6 +/- 2.2 and 12%. In 103 blood donor sera, HA was found at 22.4 +/- 16.7 micrograms/liter. HA was elevated in most of the cancer patient sera tested.

Enzymatic analysis with chondrosulfatases of constituent disaccharides of sulfated chondroitin sulfate and dermatan sulfate isomers by high-performance liquid chromatography

Various under-sulfated, monosulfated, and over-sulfated chondroitin sulfate and dermatan sulfate isomers were analyzed in terms of disaccharide units before or after desulfation with chondrosulfatases in addition to digestion with chondroitinases. The unsaturated disaccharides were separable by a high-performance liquid chromatography (HPLC) method using a resin made from a sulfonized styrene-divinylbenzene copolymer. The retention times of the parent sulfated unsaturated disaccharides and newly generated unsaturated mono- or nonsulfated disaccharides were reproducible. On desulfation of the parent sulfated unsaturated disaccharides with chondrosulfatases, almost all delta Di-S showed the same retention times as those of standard delta Di-S from known components. Following digestion of delta Di-diSB with chondro-4-sulfatase as well as delta Di-diSD or delta Di-diSG with chondro-6-sulfatase, three delta Di-monoS with the same retention time were detected with the HPLC method. These newly generated delta Di-monoS2 showed that the structure is N-acetyl-D-galactosamine, uronic acid 2-sulfate.

Polysaccharides sulfated at the time of gastrulation in embryos of the sea urchin Clypeaster japonicus

Based on the fact that the development of sea urchin embryos is arrested at the blastula stage in sulfate-free sea water (SFSW), we attempted in the present study to elucidate the nature of sulfated polysaccharides (PSs) which appear at the time of gastrulation in embryos of the sea urchin Clypeaster japonicus. Electrophoretic analysis of PSs prepared from embryos at different developmental stages revealed that three kinds of PSs (3A, 3B, 3C) appear de novo at the gastrula stage, and that these PSs are not found in embryos at the hatching blastula stage, nor are they found in permanent blastula reared in SFSW. These, three PSs were mostly of extracellular matrix origin. Among them, 3C was identified as dermatan sulfate on the basis of its electrophoretic mobility and sensitivity to enzymatic digestion. 3A and 3B remained to be identified. Further, a plausible precursor of 3C, which was sulfated under normal conditions, was detected as 6D in the embryos reared in SFSW. Autoradiographic analysis using [35S]sulfate revealed that these three PSs, accounted for more than 90% of [35S]sulfate incorporated into the acid PS fraction during gastrulation.

Distribution of acidic glycosaminoglycans, lipids and water in normal human cerebral arteries at various ages

Functional alterations in arterial acidic glycosaminoglycans (AGAG) may be related to the pathogenesis of some forms of cerebrovascular disease. We measured the AGAG, lipid and water content of human cerebral artery of 275 normal males at various ages. These measures were separately carried out in the main trunk and distal branches. The AGAG components were analyzed by an enzymatic assay method employing specific enzymes which digest AGAG to assess topographic change and aging variations. The total AGAG content was higher in the main cerebral artery than in the distal branches. The main AGAG component of the normal main cerebral artery was heparan sulfates (HS), constituting half the total AGAG, followed by moderate amounts of dermatan sulfate (DS), chondroitin-6-sulfate (C-6S) and chondroitin-4-sulfate (C-4S). Hyaluronic acid (HA) was a minor component and it was more prominent in young arteries. Heparin could be occasionally detected. With advancing age, the relative amounts of HS, HA, chondroitin and C-4S both in the main trunk and distal branches decreased but those of DS and C-6S increased. The total lipid, cholesterol ester and triglyceride content was greater in the main trunk than in the distal branches; the total lipid content increased with age. A possible function of the cerebral arterial AGAG is discussed with respect to change in lipid and water content according to topographic sites and aging.

In situ interaction of cartilage proteoglycans with matrix proteins

The interaction of proteoglycans with other matrix proteins via thiol-disulphide interchange was explored. Chick sternal cartilage was extracted with 4 M guanidine hydrochloride in the presence and absence of N-ethylmaleimide and the proteoglycans from the centrifugation A2 fractions were isolated. Those from extracts without N-ethylmaleimide were linked with reducible bonds with 10-15 proteins-glycoproteins including the link proteins, the 148 kDa and 36 kDa proteins. The same was observed with extracts of pig laryngeal and sheep nasal cartilage. The linked proteoglycans from sheep amounted to 2-3% of the extractable uronic acid and belonged to two populations. The major fraction was included by Sepharose 6B (Mr 110 000) had twice as long chondroitin sulphate chains, higher 4-sulphated residues and a high content of aspartic acid and leucine-rich protein. The larger proteoglycans had a size and composition similar to those of aggregating proteoglycans.

Angiogenesis induced by degradation products of hyaluronic acid

Partial degradation products of sodium hyaluronate produced by the action of testicular hyaluronidase induced an angiogenic response (formation of new blood vessels) on the chick chorioallantoic membrane. Neither macromolecular hyaluronate nor exhaustively digested material had any angiogenic potential. Fractionation of the digestion products established that the activity was restricted to hyaluronate fragments between 4 and 25 disaccharides in length.

A high-performance liquid chromatography for constituent disaccharides of chondroitin sulfate and dermatan sulfate isomers

An improved high-performance liquid chromatography for unsaturated disaccharides prepared from chondroitin sulfate and dermatan sulfate isomers was developed using an ion-exchange resin made from a sulfonized styrene-divinylbenzene copolymer. By this newly devised method, it was found that the retention times of representative unsaturated disaccharides are very unique and appear in the following order: unsaturated 6-sulfated, nonsulfated, and 4-sulfated disaccharides. The content of the individual unsaturated disaccharides could be measured at similar sensitivities with ultraviolet absorbance. Sensitive and unique retention times as well as good resolution were found for various unsaturated disulfated disaccharides. The new microassay method by HPLC can be used to determine chondroitin sulfate and dermatan sulfate isomers in amounts as small as 100 ng to 8 micrograms. The practicality of this method was verified by application to the separation and quantitation of chondroitin sulfate and dermatan sulfate isomers from human coronary arteries.

Cell surface glycosaminoglycans (GAGs) of cultured chick fibroblasts. Modifications in relation to the stage of embryo development

We have investigated the changes in glycosaminoglycan (GAG) composition between cultured fibroblasts derived from 8- and 16-day chick embryos. GAG composition has been studied after [3H]glucosamine and [35S]sulfate labeling. Both the 8- and 16-day embryo fibroblasts were found to contain hyaluronic acid (HA), dermatan sulfate (DS), heparan sulfate (HS) and chondroitin sulfates (CS), the latter being the major component in 8- and 16-day cells. These four GAGs were quantified after their separation using cellulose acetate electrophoresis. The amounts of HA and CS were respectively shown to increase 2-fold and 4-fold between the 8th and 16th day of development, whereas the amounts of HS and DS resp. diminished 2.5-fold and 1.2-fold. These results show that the relative proportions of the different GAGs alter during embryo development. The fibroblasts from 8-day-old embryos detached more rapidly from the culture dishes than the cells from 16-day-old embryos when treated with trypsin. However, this difference was not directly related to the different GAG content.

Distribution of Alginate Lyase Activity among Strains of Bacillus circulans

Strains from four different DNA relatedness groups of Bacillus circulans showed apparent alginate lyase activity; the activity of three strains examined had mannuronidase specificity. A representative strain of group 4 also produced apparent inducible unsulfated chrondroitin lyase activity.

Purification and characterization of hyaluronidase from oral Peptostreptococcus species

Hyaluronidase was purified to apparent homogeneity from the spent medium of Peptostreptococcus sp. strain 84H14S. The enzyme was purified 310-fold by ethanol precipitation, gel chromatography, and cation-exchange chromatography with a recovery of 42% of the original activity in the culture medium. The molecular weight of the purified enzyme was estimated to be 160,000 by gel filtration with Sephacryl S-300. Like bacterial mucopolysaccharidases of other sources, the enzyme carried out an eliminative reaction with the substrate, producing 4,5-unsaturated disaccharides as the final end products. Its optimum temperature of activity is 46 degrees C. The purified peptostreptococcal hyaluronidase was different from previously reported bacterial hyaluronidases in several respects. It degraded hyaluronic acid rapidly and also exhibited some activity against chondroitin sulfate A and chondroitin sulfate C. The KmS for hyaluronic acid, chondroitin sulfate A, and chondroitin sulfate C were 0.14, 1.4, and 2.6 mg/ml, respectively. The specific activity of hyaluronidase was much higher than that of any previously purified mucopolysaccharidases. The Vmax against hyaluronic acid reached 400 mmol of product per min per mg of protein at 22 degrees C. The peptostreptococcal hyaluronidase was also unique in that its optimum pH of activity was around neutrality, whereas other bacterial hyaluronidases were most active at acidic pHs.

High performance liquid chromatographic assay of disaccharides and oligosaccharides produced by the digestion of glycosaminoglycans with chondroitin sulphate lyases

In high performance liquid chromatographic procedures hitherto described, SiO2, NH2 and RP columns have been used for the analysis of disaccharides produced by the digestion of glycosaminoglycans with the chondroitin sulphate lyases AC and ABC. The use of a potent anion exchanger offers the following advantages over these columns: superior separation characteristics for non-sulphated disaccharides, and improved column performance, coupled with more stable analytical conditions. Elution with dilute saline solutions permits separation of the two non-sulphated disaccharides from chondroitin and hyaluronate. The sequential application of chondroitinase AC and ABC permits the determination of hyaluronate, the chondroitin sulphate isomers and the dermatan sulphate isomers by high performance liquid chromatographic separation of the products of enzymatic hydrolysis. In a previously described method, hyaluronate lyase was used for the determination of hyaluronate. It has been found, however, that omission of the hyaluronate lyase step results in superior accuracy in the high performance liquid chromatographic separation of the non-sulphated disaccharides. The enzymatic analysis of human articular cartilage glycosaminoglycans has repeatedly yielded a fraction which is not digestable by chondroitinase AC, but is completely digestable by chondroitinase ABC. More extensive characterization has disclosed that this fraction differs structurally from chondroitin sulphate. Enzymatic characterization indicates that it should presumably be assigned to dermatan sulphate.

Glycosaminoglycan-depolymerizing enzymes produced by anaerobic bacteria isolated from the human mouth

A number of obligately anaerobic bacteria, some implicated in periodontal disease, were screened for their ability to produce enzymes capable of degrading hyaluronic acid and chondroitin-4-sulphate. Two screening methods were used following anaerobic incubation at 37 degrees C for 7 days. One involved incorporating the respective substrates and bovine-serum albumin into agar plates and, after incubation, flooding the plates with 2 M acetic acid. Clear zones were produced around colonies which produced enzymes capable of depolymerizing the substrates. The second was a sensitive spectrophotometric procedure based on the ability of certain bacteria to produce eliminase enzymes, which degrade the substrates to unsaturated products having a characteristic u.v. absorption at 232 nm. Strains of Bacteroides gingivalis and Bacteroides melaninogenicus degraded both substrates whereas Bacteroides asaccharolyticus degraded neither substrate by either method. Some bacteria gave negative results with the plate method whereas the more sensitive spectrophotometric assay proved positive. The number of anaerobic bacteria capable of degrading hyaluronic acid and chondroitin-4-sulphate in vitro may therefore have been underestimated in previous studies.

Immunoelectron microscopy of proteodermatan sulfate in human mid-dermis

Proteodermatan sulfate was isolated from the skin of human, female breast in 6-M urea and proteolytic inhibitors at 70 degrees C and purified on Sephacryl S-200. It was composed of 55% protein and 45% dermatan sulfate, displayed one protein and carbohydrate-stainable band on agarose-polyacrylamide gels, yielded dermatan sulfate after digestion by papain, and its calculated E0.1% 1 cm, 280 nm was 16.2. Its mucopolysaccharide portion was digested by chondroitinase ABC but not by chondroitinase AC. This proteoglycan was used to immunize rabbits. Double diffusion of antiserum against the antigen or its core protein resulted in one precipitation band. Antiserum did not cross-react with bovine collagen type I, human fibronectin, dermatan sulfate, hyaluronic acid, heparin, heparan sulfate or the chondroitin sulfates by double diffusion. The antiserum titer determined by radioimmunoassay was 1:16,000. This assay was not affected by a 40-fold excess of dermatan sulfate. Purified IgG molecules were apparently associated with collagen in human breast mid-dermis as demonstrated by indirect immunoelectron microscopy with ferritin-labeled goat antirabbit IgG. The results indicate that rabbit anti-human, anti-proteodermatan sulfate IgG is highly specific for the core protein of dermatan sulfate and confirm the hypothesis that in vivo proteodermatan sulfate is closely associated with collagen.

Fluctuations in prostatic glycosaminoglycans during fetal and pubertal growth

Mesenchymal glycosaminoglycans have been shown to fluctuate during the development of various organs. Prostatic development is an interesting example of organogenesis as it is only at puberty, under androgen influence, that differentiation is completed. We have extracted and quantitated the glycosaminoglycans of human prostates obtained from fetuses, prepubertal, and adult males to determine the changes that occur during prostatic differentiation. The total glycosaminoglycan content per prostate followed the wet weight growth curve. The percentages of heparan sulfate and heparan sulfate sulfation seemed to correlate with prostatic epithelial differentiation. After 25 years of age prostatic glycosaminoglycan concentrations tend toward the glycosaminoglycan ratios typical of benign prostatic hyperplasia.

Glycosaminoglycans in human gingival crevicular fluid as indicators of active periodontal disease

The glycosaminoglycans (GAG) in gingival crevicular fluid (GCF) were investigated by cellulose-acetate electrophoresis of samples from individual sites of defined conditions variously affecting the tissues of the periodontium. The non-sulphated GAG, hyaluronic acid, was present in all samples and was the only major band from sites of chronic gingivitis. An additional sulphated GAG band identified by enzymic digestions as chondroitin-4-sulphate, was detected in GCF from sites of untreated-advanced periodontitis. Initial samples from sites of early periodontitis and juvenile periodontitis yielded a similar additional band which was not detected, however, in samples collected after either surgery to eliminate deep pockets or daily subgingival irrigation with a chlorhexidine solution. Sulphated GAG was also present in fluid from the control situations, i.e. of teeth either undergoing orthodontic movement or showing evidence of trauma from occlusion, and from healing tooth-extraction wounds. Thus the presence of such a component in GCF correlates with those clinical conditions in which degradative changes are occurring in the deeper-periodontal tissues. The electrophoretic profile of GAG in a sample of GCF may be a sensitive laboratory method of indicating active phases of destructive periodontal disease at individual sites.

Immunochemical and biochemical characterization of a glioma-associated extracellular matrix glycoprotein

A novel human glioma-associated extracellular matrix (ECM) glycoprotein has been identified by murine monoclonal antibody 81C6. The glycoprotein, designated GMEM, is expressed in the ECM of glioma and mesenchymal cell cultures, in the perivascular matrix of endothelial proliferations of human gliomas, and in the stroma of human glioma xenografts in athymic mice, where it has been used as a target antigen for monoclonal antibody tumor localization and radioimaging. We report here on the immunochemical and biochemical characterization of GMEM. Polyacrylamide gel analysis of immunoprecipitated [3H]-leucine- and [3H]-glucosamine-labeled ECM from the human glioma cell line U-251MG has shown that GMEM is a high-molecular-weight macromolecule (Mr approximately 1,000,000) composed of Mr approximately 230,000 disulfide-bonded glycoprotein subunits. Immunoprecipitation, immunoblot, and one-dimensional peptide map analysis have shown that GMEM is distinct from human fibroblast and plasma fibronectin. These results support previous immunohistology and absorption analysis findings, indicating that GMEM is distinct from fibronectin, laminin, and glycosaminoglycans secreted by U-251MG.

The histochemistry of urea-unmasked glycosaminoglycans in the skin of the eel, Anguilla japonica

In the connective tissues of the dermis and subcutis of the eel skin, the histochemistry of urea-unmasked glycosaminoglycans has been studied by means of combined staining and enzyme digestion procedures. The staining procedures employed were alcian blue (AB) pH 1.0, AB pH 2.5, aldehyde fuchsin (AF), periodic acid-Schiff (PAS), AB pH 2.5-PAS, high iron diamine (HID) and low iron diamine (LID) methods, whereas the enzymes used were Streptomyces and testicular hyaluronidases, chondroitinases ABC and AC and keratanase. The results obtained have shown that a substantial amount of dermatan sulfate and a relatively small amount of hyaluronic acid, chondroitin, chondroitin sulfate A and/or C were the glycosaminoglycans involved in the connective tissues of the eel skin and that the tissues were devoid of keratan sulfate.

Evidence for diabetes-induced alterations in the sulfation of heparin sulfate intestinal epithelial cells

35S-heparan sulfate (HS) metabolism by intestinal epithelial cells isolated from streptozotocin-diabetic and control rats was studied. In diabetic cells, a greater amount of 35S-radioactivity was incorporated into HS, however specific radioactivity of this polysaccharide was decreased. Studies into the distribution of sulfate residues in HS after selective deamination of the glucosamine units within the glycosaminoglycan (GAG)-chain, demonstrated that O-sulfate groups are preferentially located in relatively small deamination products: tetrasaccharides and disaccharides. A lower amount of radioactivity related to N-sulfate groups was found in HS from diabetic cells compared to that of control cells demonstrating that, in diabetes, less glucosamine residues within HS chains are subjected to N-sulfation. An increase in the percentage of 35-sulfate and in the percentage amount of uronic acid in tetrasaccharides of HS of diabetic cells indicated that a greater number of tetrasaccharides were generated by deaminative degradation of this HS. Since a decrease in the specific activity of uronic acid in disaccharides as in tetrasaccharides from HS of diabetic cells was observed, it is clear that the degree of O-sulfation of this HS is reduced. It is suggested, that "in vivo" changes in HS metabolism in diabetic intestinal epithelial cells lie in a disturbance in the degree of N- and O-sulfation of disaccharide units within the HS macromolecule.

Histochemical analysis of urea-unmasked glycosaminoglycans in the skin of the rat and mouse

Histochemical analysis of urea-unmasked glycosaminoglycans has been performed in connective tissues of the rat and mouse skin by means of combined staining and enzyme digestion procedures. The staining procedures used were Alcian Blue pH 1.0, Alcian Blue pH 2.5, Aldehyde Fuchsin, periodic acid-Schiff (PAS), Alcian Blue pH 2.5-PAS, high iron diamine and low iron diamine methods. The digestive enzymes employed were Streptomyces and testicular hyaluronidases, chondroitinases ABC and AC and keratanase. The results obtained indicated that the major components of the glycosaminoglycans in the connective tissues of the skin were hyaluronic acid, dermatan sulphate and chondroitin sulphate A and/or C, whereas the tissues were devoid of keratan sulphate.

Hyaluronidase polymorphism detected by polyacrylamide gel electrophoresis. Application to hyaluronidases from bacteria, slime molds, bee and snake venoms, bovine testes, rat liver lysosomes, and human serum

A gel electrophoretic technique which allows detection of hyaluronidase activity in the gel has been devised. The principle is that the high-molecular-weight substrate, hyaluronic acid, is included in the gel, where it cannot move in the electrical field. After the run, the gel is incubated under conditions allowing the enzyme to degrade the substrate. Upon staining with "Stains-all" dye (Eastman Kodak Co., 2718), zones of hyaluronidase activity appear as pink bands in a blue background. The sensitivity limit is less than 3 fkat equivalent to 2.2 NF mU. The method is applicable to all types of hyaluronidases and chondroitinase ABC. It enabled to be shown that some hyaluronidases are polymorphic. This technique also made it possible to detect easily hyaluronidase activity in normal human serum. This analytical method represents a convenient step in the purification of hyaluronidase.

Partial chemical characterization of the anionic sites in the basal lamina of fenestrated capillaries

The distribution of anionic sites in the basal laminae of the blood capillaries of the murine pancreas was studied in specimens fixed in ruthenium red (RR)-glutaraldehyde mixtures. The sites appeared as discrete, small (6 to 18 nm) particles distributed throughout the three laminae but concentrated primarily in the lamina rara externa, in which--spaced 80-100 nm apart--they formed a planar, partially ordered lattice comparable to that revealed by cationized ferritin in previous studies (M. Simionescu, N. Simionescu, and G. E. Palade, 1982, J. Cell Biol. 95, 425-434). The chemical nature of the anionic sites was explored by incubating fresh tissue specimens in solutions of selected enzymes before fixation in RR-glutaraldehyde mixtures. Pronase P and papain removed completely the anionic sites and left behind an extensively degraded and disorganized basal lamina. Trypsin caused the removal of anionic sites only, did not degrade the rest of the basal lamina, but detached it completely from the endothelium. Chondroitinase ABC reduced slightly the size and the surface density of RR-stainable particles, and detached focally the rest of the basal lamina from the endothelium and pericytes. Crude heparinase caused a nearly complete removal of anionic sites, and pure heparitinase gave comparable but less extensive results. Similar effects were recorded on the basal laminae of smooth muscle fibers and pancreatic acini and ducts. The results indicate that the anionic sites of all basal laminae examined are contributed primarily by heparin sulfate proteoglycans and trace amounts of chondroitin sulfate proteoglycans.

Immunocytochemical localization of native chondroitin-sulfate in tissues and cultured cells using specific monoclonal antibody

Chondroitin-sulfate containing proteoglycan (CSPG) of the extracellular matrix (ECM) was visualized in chick tissues and cell cultures with a monoclonal antibody, CS-56. Cultured cells of various origins contained dense punctate layers of CSPG on both the substrate and the cell surface, as determined by immunofluorescent and immunogold staining. Under culture conditions the CSPG-containing matrix was usually excluded from stable cell-to-substrate focal contacts. The substrate-attached CSPG exhibited remarkable chemical stability but could be successfully removed by pronase or chondroitinases ABC and AC. Incubation of living cells with CS-56 antibodies resulted in the clustering of surface CSPG into patches, indicating that the surface-bound CSPG is free to move laterally along the plasma membrane. The unique properties of the CSPG-containing ECM revealed by CS-56 antibodies and their relationships to specific types of cell contacts are discussed.