Purification and Properties of Bacterial Chondroitinases and Chondrosulfatases

Papillary carcinoma of choroid plexus. Light and electron microscopic study

Two cases of papillary carcinoma, one in a 23-month-old girl and the other in a 25-month-old boy who both died within a relatively short time after operation, were studied histologically and electron microscopically. Both tumors originated in the right trigone of the lateral ventricle and spread widely via the cerebrospinal fluid. Histologically, the tumors consisted mostly of a differentiated papillary architecture closely resembling choroid plexus papilloma. Some carcinoma cells, showing cellular atypism, displayed a multilayer arrangement. The amount and distribution of PAS-, Alcian blue-, or orcein-positive substances on the cell surface and/or in the interstitial elements of the carcinomas differed from that of choroid papillomas examined in our laboratory. Electron microscopically, the carcinoma cells in some areas showed a loss of apical-basal polarity, and the formation of both microvilli and desmosome-like structures was indistinct. Papillary carcinoma is reviewed on the basis of the literature from 1906 till 1980.

Abnormal urinary excretion of glycosaminoglycans in Albers-Schönberg disease

Abnormal urinary excretion of acid mucopolysaccharides in two children affected with Albers-Schönberg disease is described. The urine specimens were first checked for their acid glycosaminoglycan (AGAG) content by a screening test. The AGAGs were then evaluated by uronic acid determination using the carbazole method, and the ratio between high molecular mass and low molecular mass AGAGs was determined. Qualitative characterization, before and after enzymatic digestion with chondroitinases AC (ChAC) and ABC (ChABC), of the total AGAGs contained in the specimen and of each AGAG separated with Dowex 1X2 was also performed by electrophoresis. The pattern of the urinary mucopolysaccharides in the two patients showed an abnormal quantity of heparan sulphate (HS) and a smaller quantity of dermatan sulphate (DS). Such abnormal urinary AGAGs excretion should confirm the assumption of some authors that malignant infantile osteopetrosis may be caused by a deficiency in the lysosomal enzymatic activity, or by some anomaly in the cell membrane function.

Mode of action of heparin lyase on heparin

Heparinase (heparin lyase, EC 4.2.2.7) prepared from Flavobacterium heparinum was used to digest heparin. The products of digestion were examined with a viscosometric assay at various stages of the reaction to measure their average molecular weight. By comparison with computer simulations of various models, heparinase was shown to act in a random endolytic mode. The relative abundance of intermediates in heparin degradation catalyzed by heparinase immobilized on Sepharose 4B was measured by high pressure liquid chromatography (HPLC) at various time points. The results obtained using HPLC were consistent with a random endolytic mechanism. The heparin digestion products were separated and identified using gel permeation chromatography. The final distributions of heparin degradation products for free and immobilized heparinase were identical. Contaminating sulfatases and glycuronidases which could have subsequently acted on heparin degradation products were not found in significant amounts in the heparinase preparation studied.

Cell-associated glycosaminoglycans of human teratocarcinoma-derived cells of line PA 1

Human teratocarcinoma-derived cells of line PA 1, which are capable of differentiating in vitro [Zeuthen, J. et al. (1980) Int J. Cancer, 25, 19-32], incorporate label from radioactive sulfate and/or glucosamine into several large-sized glycosaminoglycans including hyaluronate, chondroitin sulfate/dermatan sulfate co-polymers, heparan sulfate and keratan-sulfate-like molecules. All these polysaccharide fractions were identified by specific degradation methods. The labeled hyaluronate was degraded into a mixture of unsaturated octa-, hexa- and tetra-saccharides by a treatment with Streptomyces hyaluronidase (EC 4.2.2.1). The chondroitin sulfate/dermatan sulfate co-polymers were cleaved with chondroitin AC lyase (EC 4.2.2.5) into unsaturated disaccharides and a series of unsaturated oligosaccharides; the latter were degraded by a treatment with chondroitin ABC lyase (EC 4.2.2.4) into unsaturated disaccharides. Heparan sulfate was degraded with nitrous acid into free inorganic [35S]sulfate and a series of [35S]sulfate-labeled oligosaccharides and/or glycopeptides. The keratan-sulfate-like molecules were hydrolyzed by a treatment with endo-beta-galactosidase from Escherichia freundii into a series of distinct [35S]sulfate-labeled oligosaccharides; small oligosaccharides were liberated also from [3H]galactose-labeled molecules. The smallest one of the liberated oligosaccharides was tentatively identified as a sulfated disaccharide.

Electron microscopic observations on pulmonary connective tissue stained by Ruthenium Red

Ultrastructural studies on human lung were performed with special attention to the interstitial acid mucopolysaccharides by Ruthenium Red staining and several enzyme digestion tests with Streptomyces hyaluronidase, chondroitinase ABC, chondroitinase AC, heparinase, trypsin and collagenase. Periodic lateral granules on the major cross bands of collagen fibrils and amorphous coats on them became visible by Ruthenium Red staining. The surface of elastic fibres, associated microfibrils, and some fine fibrils 10-20 nm in diameter were stained. Ruthenium Red also stained the surface of fibroblast and smooth muscle cells, basement membrane and filamentous long segments. In the interstructural space, granular substances 10-80 nm in diameter and fine filaments 3--4 nm thick, which formed a fine reticular network, were clearly observed. They were not visible on the usual thin section. The granular substances were located on the cross points of the fine filaments. They spread continuously and connected with each of the cells and extracellular structures in the pulmonary interstitium. The results of the enzyme digestion tests on the Ruthenium Red-positive material are discussed.

Glycosaminoglycan synthesis by Dupuytren's cells in culture

Glycosaminoglycan synthesis by cells cultured from nodule or band tissues of patients with Dupuytren's disease was compared with that of skin fibroblasts cultured from uninvolved areas of the palm. No differences were observed in culture which could account either for the abnormal glycosaminoglycan content or the increased cellularity of the diseased tissues. It is suggested that the behavior of Dupuytren's cells in vivo may result from a response to local conditions within the palm rather than from the expression of an irreversible change in their glycosaminoglycan metabolism.

Characterization of glycosaminoglycans associated with Rauscher murine leukemia virions

Host-derived sulfated components that copurify and are physically associated with the envelope of Rauscher murine leukemia virions grown in JLS-V9 cells were characterized by digestion with chondroitinase ABC and chondroitinase AC II, as well as nitrous acid degradation. A dermatan-sulfate-chondroitin-sulfate copolymer and heparin or heparan sulfate wee shown to be associated with the virions. Competitive binding studies indicated a specificity of the virions for association with heparan sulfate. The physiological importance of the association is discussed.

Effects of Streptomyces hyaluronidase digestion on the histochemical reactions of proteoglycans in cartilage compared with its effects on certain non-cartilaginous tissues

To test the value of Streptomyces hyaluronidase in carbohydrate histochemistry, the effects of digestion with the enzyme on the staining of cartilage and non-cartilaginous tissues by Alcian Blue (AB) pH 1.0, AB pH 2.5, high iron diamine, low iron diamine, aldehyde fuchsin, dialysed iron-ferrocyanide and AB pH 2.5-periods acid-Schiff were studied by light microscopy. The results obtained lead to the conclusion that the Streptomyces enzyme releases not only hyaluronic acid but also chondroitin sulphates and keratan sulphates in cartilage. Since hyaluronic acid is known to be linked to chondroitin sulphate proteoglycans, the enzyme is of limited value in localizing hyaluronic acid in cartilage. However, it is useful in localizing hyaluronic acid in most non-cartilaginous tissues.

Measurement of serum glycosaminoglycans by laser nephelometry

A simple, sensitive micromethod for the assay of serum hyaluronic acid and chondroitin sulphates is presented. The method is based on the binding of the quaternary ammonium salt, cetylpyridinium chloride (CPC) to serum polyanions, and quantitation of the complexes by laser nephelometry. Measurement of the CPC complexes in serum before and after digestion with specific enzymes enables quantitation of hyaluronic acid and chondroitin sulphates in less than 100 microliters serum. Using this technique, hyaluronic acid is detectable in a small number of normal human sera at concentrations up to 4 mg/l, and chondroitin sulphates are consistently present at concentrations ranging from 2 to 25 mg/l.

Effect of cycloheximide and dexamethasone phosphate on hyaluronic acid synthesis and secretion in cultured human skin fibroblasts

We have studied some aspects of the regulation of hyaluronic acid synthesis in cultured human skin fibroblasts derived from normal individuals. In these cells 85% of radiolabeled glucosamine is incorporated into two types of macromolecules, hyaluronic acid and glycoproteins, characterized by district partitions between the cell and medium compartments. Treatment of cells with cycloheximide under conditions in which protein and glycoprotein synthesis is inhibited by at least 90% has no effect on hyaluronic acid synthesis. This result is consistent with the hypothesis that protein synthesis is not necessary for the synthesis of hyaluronic acid. Conversely, 5 X 10(-6) M dexamethasone phosphate inhibits hyaluronic acid by 60% but has no effect on protein or glycoprotein or glycoprotein synthesis. Concomitant treatment with dexamethasone phosphate and cycloheximide restores the synthesis of hyaluronic acid to normal values. The dexamethasone phosphate effect on hyaluronic acid synthesis is therefore not a primary induction response since it requires protein synthesis. The secretion of hyaluronic acid and glycoproteins from the cells into the medium is not affected by either of the two drugs. This experimental approach will be useful in the study of the regulation of glycosaminoglycan metabolism in human cells especially with respect to disorders of connective tissue.

Low urinary excretion of heparan sulfate in three patients with Lowe's syndrome

Urinary glycosaminoglycans were isolated with the cetylpyridinium chloride (CPC) precipitation method and the excretion of individual species of urinary glycosaminoglycans in three patients with Lowe's syndrome was compared with that of age-matched control children by means of electrophoresis on cellulose acetate membranes and by quantification of hexosamine contents. Total daily excretion of urinary glycosaminoglycans in the patients seemed to be normal, but the relative excretion of urinary heparan sulfate was significantly reduced and ranged from 26 to 46% of the age-matched control mean, when calculated on the basis of relative glucosamine content in urinary glycosaminoglycans. Although electrophoretograms of urines from patients with Lowe's syndrome suggested some excess of low sulfated chondroitin sulfate corresponding in mobility to dermatan sulfate, the enzymatic subunit assay employing chondroitinases did not disclose any significant differences in the excretion pattern or in the degree of sulfation of chondroitin sulfate isomers between lowe's syndrome and control children.

Circumscribed myxoedema of lichen myxoedematosus as a sign of faulty formation of the proteoglycan macromolecule

Using a new method devised by our laboratory, the ultrastructure of dermal glycosaminoglycan in an involved area of lichen myxoedematosus was examined. Although histochemical and biochemical studies have indicated simply an accumulated deposition of hyaluronic acid in the lesion, the glycosaminoglycan ultrastructure within it was distinctly different from that in normal skin. The glycosaminoglycan structure of normal skin was similar to the proteoglycan aggregate model described by Rosenberg (1975). As confirmed by the enzymatic digestion procedure, it represents the ultrastructure of hyaluronic acid bound to glycosaminoglycans such as dermatan sulphate or chondroitin sulphate. In contrast, hyaluronic acid filaments observed in lesions of lichen myxoedematosus contained no glycosaminoglycan subunits.

Effects of retinal growth factor and of the increase of the number of subcultures on sulfated glycosaminoglycans of bovine lens epithelial cells

Sulfated glycosaminoglycans of cultured bovine lens epithelial cells grown in the presence and in the absence of a retinal growth factor were investigated comparatively. The newly formed [35S]sulfate-labeled glycosaminoglycans were analysed in the extra-, peri- and intracellular compartments of early (4--5th) and late 17--18 h) subcultures. The following results were obtained: (1) Cultured lens epithelial cells grown in the presence or in the absence of the growth factor synthesize chondroitin 4- and 6-sulfates and dermatan sulfate, with heparan sulfate as the main component, the pericellular compartments were particularly rich in heparan sulfate; (2) The distribution pattern of the glycosaminoglycans changes during successive subcultures; the proportion of heparan sulfate increases in the pericellular compartment, the dermatan sulfate to chondroitin sulfate ratio increases in all three compartments; (3) IN contrast to the drastic decrease in the fibronectin levels in the presence of growth factor in the early subcultures, only minor differences were found between the glycosaminoglycan patterns of the treated and non-treated cells.

Ultrastructure of the mouse synovial membrane. Development and organization of the extracellular matrix

The synovial membrane of the mouse knee joint was examined by electron microscopy and electron microscopic histochemistry, with special reference to the development of the extracellular matrix. In the embryonic synovium, the intercellular spaces were filled with hyaluronate and chondroitin sulfate. The formation of the early joint cavity appeared to be initiated by accumulation of hyaluronate and chondroitin sulfate in the synovial primordium. At the postnatal stage, the synovial primordium differentiated into a true synovial intima that could be easily identified by the presence of two distinct lining cells: fibroblast-like cells (B cells) and phagocytic cells (A cells). Simultaneously, the synovial intima provided the specialized extracellular matrix that was characterized by organized structures of microfibrils, collagen fibers, and fibrous long spacing fibers embedded in a large number of glycoproteins.

Purification of a high-affinity discoidin I-binding proteoglycan from axenic Dictyostelium discoideum growth medium

The axenic Dictyostelium discoideum growth medium HL-5, prepared using Difco proteose peptone No. 2, contains an extremely potent inhibitor of the binding of 125I-labeled discoidin I to glutaraldehyde-fixed, cohesive D. discoideum cells. Axenic strain A3 D. discoideum cells bind or internalize the inhibitor during growth in HL-5 medium and subsequently shed or excrete it while differentiating in suspension. The inhibitor has been purified from Difco proteose peptone No. 2 by sequential gel filtration on Sepharose 4B and affinity adsorption using discoidin I-Sepharose. The inhibitor is heterogeneous in molecular weight (4 . 10(5)--2 . 10(6)), but is relatively homogeneous in density on CsCl density gradients. The size and activity of the inhibitor are resistant to periodate, reduction and maleylation, proteases, nucleases and heating in the absence or presence of sodium dodecyl sulfate. Mild alkali causes a partial reduction in activity and converts the higher molecular weight fraction of the inhibitor to a lower molecular weight. The purified inhibitor contains neutral hexose, hexosamine and amino acid in an approximate molar ratio of 4 : 3 : 2. These and other properties suggest that the inhibitor is an unusual proteoglycan. Certain well-characterized glycosaminoglycans are relatively potent inhibitors of discoidin I binding. The proteoglycan reported here is the most potent discoidin I-binding inhibitor ever identified.

The binding of chondroitin 6-sulfate to plasma low density lipoprotein

The interaction in vitro of several sulfated glycosaminoglycans with low density lipoproteins (LDL) has been studied. Chondroitin 6-sulfate and heparin were the only ones to produce turbidity when added to LDL in presence of Ca2+. However, when these two glycosaminoglycans were applied to LDL-affinity columns in presence of Ca2+, only chondroitin 6-sulfate was retained. Partially desulfated chondroitin 6-sulfate was not retained on LDL-affinity column, indicating the relevance of sulfate groups in the binding of LDL. Since chondroitin 4-sulfate and heparin, with a sulfate content respectively equal to and greater than that of chondroitin 6-sulfate, are not retained on LDL-affinity columns, the factors relevant to the binding of LDL are probably the conformation of the glycan in solution and the orientation of its sulfate groups.

A high level of glycosaminoglycan-synthesis of squamous cell carcinoma of the parotid gland

Glycosaminoglycan content of a squamous cell carcinoma derived from the parotid gland was analyzed. The tumor tissue contained a large amount of glycosaminoglycans, and the amount was strikingly larger than found in other kinds of tumor tissues (pleomorphic adenoma, scirrhous carcinoma, myxoma, etc.) analyzed previously. A culture cell line established from this tumor showed a morphologic characteristic of differentiated squamous cell carcinoma, in vitro, forming many tonofilaments in the cytoplasma and numerous desmosomes in the intercellular connection. The carcinoma cell synthesized and secreted a large amount of glycosaminoglycans, consisting mainly of hyaluronic acid. The amount of 3H-labelled hyaluronic acid secreted by this carcinoma cell was about 20-fold larger than that by HeLa cell or KB cell. Conceivably, a high level of hyaluronic acid synthesis is one of the biologic characteristics of squamous cell carcinoma derived from the duct epithelium of the salivary gland.

Glycosaminoglycan biosynthesis in arterial wall. Sulfation of heparan sulfate in cell membrane of aortic media-intima

Incubation of microsomal fractions with labelled 3'-phosphoadenylyl sulfate results in incorporation of [35S]sulfate into endogenous glycosaminoglycans. Specific radioactivity observed incorporated into heparan sulfate chains is 10-fold greater than that incorporated into chondroïtin sulfate chains. This is in agreement with the results obtained for glycosylation of glycosaminoglycans in arterial wall membrane fractions. Sulfation of heparan sulfate was studied since it contains N- and O-sulfate groups in contrast with the other sulfated glycosaminoglycans which contain only O-sulfate groups. Sulfation of heparan sulfate occurs rapidly, since sulfate incorporation is detected after exposure for only 0.5 min. Heparan sulfate was identified on the basis of its resistance to hyaluronidase and chondroïtin ABC lyase, its susceptibility to heparitinase, its sensitivity to nitrous acid and the presence of glucosamine as the only hexosamine. The chemical composition of the purified heparan sulfate fractions provides evidence for the high degree of sulfation of its chains. Studies into the distribution of sulfate residues on heparan sulfate at different times of sulfation indicate that N-sulfate groups are not randomly introduced into the polymer. The relationship between the processes of N- and O-sulfation was studied. The present results demonstrate that preferential N-sulfation is obtained for incorporation of labelled precursor over a short period, the O-sulfation occurring on previously N-sulfated heparan sulfate.

Phosphate ester groups in proteoglycans from bovine nasal cartilage

1. Proteoglycan subunits isolated by standard procedures from bovine nasal cartilage, previously incubated in the presence of [32P]phosphate contain [32]-phosphate ester groups as a regular structural component. 2. Contamination of the proteoglycan subunit with 32P-labeled nucleic acids could be excluded by repeated cesium chloride density gradient centrifugation under associative and dissociative conditions, lanthanum chloride precipitation, gel filtration and by the resistance of the proteoglycan subunit associated 32P to phosphoric diester hydrolases. 3. The [32P]phosphate ester groups are associated to the chondroitin sulfate peptide fraction obtained by proteolytic digestion of the proteoglycan subunit molecule. Degradation of the chondroitin sulfate peptide by chondroitinase ABC resulted in a 32P-labelled oligosaccharide peptide fraction, that contains xylose, galactose, glucuronic acid and inorganic phosphate in a molar ratio 1 : 2 : 1 : 0.12. 4. 32P radioactivity is released as inorganic phosphate by treatment of the 32P-labelled oligosaccharide peptide with acid phosphatase or alkali.

Distribution of membrane glycoproteins among the organelles of a single identified neuron of Aplysia. II. Isolation and characterization of a glycoprotein associated with vesicles

Glycoprotein-I (mol.wt. 180,000) is associated with a vesicle fraction from the cytoplasm of R2, the giant cholinergic neuron in the abdominal ganglion. Electron microscopy has shown that R2 contains both lucent and compound vesicles. We have used anisomycin, an inhibitor of protein synthesis, to provide evidence that Component-I is a constituent of somatic compound vesicles. In the presence of the drug, [3H]N-acetylgalactosamine injected into R2 is incorporated almost exclusively into Component-I. Quantitative electron microscopic radioautography of treated cells shows a marked increase in the proportion of silver grains over compound vesicles and a decrease in labeling of other organelles compared with untreated cells. Analysis of Component-I, isolated using the chaotropic agent lithium diiodosalicylate, shows it to contain fucose, N-acetylgalactosamine, and N-acetylglucosamine. Proteolytic digestion with pronase yields a complex pattern of glycopeptides. The proportion of [3H]N-acetyl-galactosamine in these glycopeptides is altered in the presence of anisomycin. These results together with radioautographic analyses suggest that large carbohydrate chains are elaborated within the endoplasmic reticulum and that smaller chains are added in the Golgi region or on the membrane of the compound vesicle.

Changes in cell-surface glycosaminoglycans in human diploid fibroblasts during in vitro aging

Changes in glycosaminoglycans during in vitro aging were investigated in human diploid fibroblasts. The cells were found to produce predominantly hyaluronate and smaller amounts of chondroitin 4-sulfate, chondroitin 6-sulfate, dermatan sulfate and heparan sulfate. Accumulation of heparan sulfate on the cell surface was notable during aging. Total glycosaminoglycan production in preconfluent culture did not change with population doubling level (PDL), while in confluent culture a decline in glycosaminoglycan production was observed. In contrast with this, heparan sulfate on the cell surface increased as a function of PDL in both confluent and preconfluent cultures. The distribution pattern of heparan sulfate in medium and cell surface indicated that the increase in heparan sulfate on the cell surface could be attributed to an increased accumulation on the cell surface, but not to an elevated production. Thus, we conclude that the increased accumulation of heparan sulfate on the cell surface might be involved in an age-related alteration in the cell membrane.

Effect of dibutyryl cyclic AMP on the sulphation of proteoglycans by chondrocytes

The addition of a 1 mM N6, O2'-dibutyryl cyclic AMP to incubations of foetal calf articular cartilage for a 4 h period resulted in a 13 and a 15% decrease, respectively, in the rate of incorporation of [3H]glucosamine and [14C]glucose into glycosaminoglycans. Under the same conditions, a 41% increase in the rate of incorporation of [35S]sulphate into glycosaminoglycans was observed. Dibutyryl cyclic AMP had no effect on protein synthesis over a 4 h period or on the hydrodynamic size of the proteoglycan subunits or glycosaminoglycans synthesized by the cartilage. When the glycosaminoglycans were digested with chondroitin ABC lyase and the resulting disaccharides analysed on Dowex 1 (formate form), it was observed that dibutyryl cyclic AMP increased the degree of sulphation of the disaccharides. Furthermore, an over-sulphated disaccharide corresponding to chondroitin 4,6-disulphate was identified. It was concluded that dibutyryl cyclic AMP was stimulating the process of sulphation of glycosaminoglycans by cartilage.

Separation of heparin into fractions with different anticoagulant activity by hydrophobic interaction chromatography

Hog mucosal heparin purified on Sephadex G-100 (anticoagulant activity assayed by the method of the United States Pharmacopoeia, 179 units/mg) was separated by hydrophobic interaction chromatography on Phenyl-Sepharose CL-4B into two groups, one with high affinity and another with low affinity for the gels. The former group was further separated into three fractions differing in hydrophobicity. The anticoagulant activities of the fractions with higher hydrophobicity ranged from 210 to 254 units/mg, whereas that of the fraction with lower hydrophobicity was 100 units/mg. The difference in antithrombin III-activation potency was much more prominent. The data obtained from affinity chromatography of these fractions on antithrombin III-Sepharose also substantiated the observed difference in anticoagulant activity. Analytical data of the fractions revealed a characteristic difference in both N-acetyl content and molecular size. While the N-acetyl content (mol/mol of hexosamine) and Kav value (on Ultrogel AcA44) of the fraction with the lowest hydrophobicity were 0.12 mol and 0.48, those of the fractions with higher hydrophobicity were 0.15-0.17 mol and 0.35-0.23, respectively.

Stimulation of glycosaminoglycan sulfotransferase from chick embryo cartilage by basic proteins and polyamines

A soluble glycosaminoglycan sulfotransferase (3'-phosphoadenylylsulfate:chondroitin 4'-sulfotransferase, EC 2.8.2.5) from chick embryo cartilage has been prepared free from endogenous acceptor. The reaction with this enzyme preparation was stimulated by basic proteins and polyamines, the degree of stimulation being dependent on the chemical nature of both basic compounds and acceptor glycosaminoglycans. A maximum stimulation was obtained when protamine (basic compound) and chondroitin (acceptor) were involved in the reaction mixture at a molar ratio of protamine to repeating disaccharide units of chondroitin, 1:100. The stimulation of sulfotransferase activity by basic substances was much higher than that by Mn2+. However, increasing the Mn2+ concentration immediately reduced the stimulation by basic substances. The Km value for 3'-phosphoadenosine 5'-phosphosulfate of the sulfotransferase, when chondroitin was used as acceptor, was 1 . 10(-6) M in the presence of 25 microgram/ml protamine, compared to 2 . 10(-5) M in the absence of protamine. These observations indicate that the basic proteins and polyamines may interact with acceptor polysaccharide, thereby causing an increase in the affinity of the enzyme toward 3'-phosphoadenosine 5'-phosphosulfate.

Compositional changes of urinary acidic glycosaminoglycans in progressive systemic sclerosis

The compositional changes of acidic glycosaminoglycans (AGAG) in the urine of progressive systemic sclerosis (PSS) patients were studied using chondroitinases and heparitinase in appropriate enzyme assays and by electrophoretic characterization. Daily urinary excretion of AGAG in patients with PSS was increased, when compared to normals. The proportion of urinary AGAG in PSS patients, which was undigested by chondroitinase-ABC (most probably representing heparan sulfates (HS)), increased significantly from the normal value. The substance was found to be mainly HS as determined by the electrophoretic pattern, thin-layer chromatographic analysis and by its susceptibility to heparitinase. After digestion of urinary chondroitin sulfate isomers with chondroitinases, the unsaturated disaccharides were mainly separated into 4-sulfated and 6-sulfated disaccharide units by paper chromatography. In all of the patients with PSS, the ratio of the unsaturated 4-sulfated disaccharide to the unsaturated disaccharide was higher than that in normal subjects. These observations indicate an abnormal turnover of AGAG in patients with PSS.

Induction of chondroitin sulfate lyase activity in Bacteroides thetaiotaomicron

Chondroitin sulfate lyase (EC 4.2.2.4) was present constitutively at low levels (0.06 to 0.08 U/mg of protein) in cells of Bacteroides thetaiotaomicron which were growing on glucose or other monosaccharides. When these uninduced bacteria were incubated with chondroitin sulfate A (5 mg/ml), chondroitin sulfate lyase specific activity increased more than 10-fold within 90 min. Synthesis of ribonucleic acid and of protein was required for induction, and induction was sensitive to oxygen. The disaccharides which resulted from chondroitinase action did not act as inducers, nor did tetrasaccharides or hexasaccharides obtained by digestion of chondroitin sulfate with bovine testicular hyaluronidase. None of these substances was taken up by uninduced cells; they may not have been able to penetrate the outer membrane. The smallest oligomer capable of acting as an inducer was the outer membrane. The smallest oligomer capable of acting as an inducer was the octassacharide. Oligomers larger than the octassacharide induced chondroitin lyase activity nearly as well as intact chondroitin sulfate.

Cellular location of enzymes involved in chondroitin sulfate breakdown by Bacteroides thetaiotaomicron

Bacteroides thetaiotaomicron, a gram-negative anaerobe found in human colons, could utilize chondroitin sulfate, a tissue mucopolysaccharide, as its sole source of carbohydrate. The enzymes responsible for the breakdown of chondroitin sulfate by B. thetaiotaomicron were similar to those produced by Proteus vulgaris and Flavobacterium heparinum and included a lyase (EC 4.2.2.4), which degraded chondroitin sulfate into sulfated disaccharides, sulfatases (EC 3.1.6.4), which removed the sulfate residues, and a glucuronidase, which broke the unsulfated disaccharides into monosaccharide components. Chondroitin sulfate lyase, the first enzyme in the breakdown sequence, was not extracellular. It appeared to be located in the periplasmic space since lyase activity was released by treatment with ethylenediaminetetraacetate and lysozyme. Moreover, sodium polyanethole sulfonate, a high-molecular-weight inhibitor of chondroitin lyase, did not inhibit breakdown of chondroitin sulfate by intact bacteria. The sulfatase and glucuronidase appeared to be intracellular. None of these enzymes was strongly bound to membranes, and none of the steps in the breakdown of chondroitin sulfate was sensitive to oxygen.