Application of nitrous acid deamination of hexosamines to the simultaneous GLC determination of neutral and amino sugars in glycoproteins

Favin versus concanavalin A: Circularly permuted amino acid sequences

We have determined the tentative amino acid sequence of the beta chain (M(r) 20,000) of the lectin favin. In previous studies, we have shown that the alpha chain (M(r) 5600) of this lectin is homologous to a region in the middle of the concanavalin A (Con A) sequence (residues 70-119). Now we present evidence that the beta chain is homologous to two discrete segments of Con A. The homology begins at residue 120 of Con A, extends to the COOH terminus (residue 237) and continues without interruption through the NH(2)-terminal 69 residues of Con A. Together, the alpha and beta chains of favin account for a polypeptide chain equivalent in size to that of Con A. The comparison of the two proteins thus reveals a circular permutation of extensive homologous sequences. The favin molecule contains residues identical to many of the residues postulated to be involved in sugar binding by Con A, and contains all of the direct metal ligands as well as residues homologous to most of the residues that form the beta-pleated sheets of Con A. These homologies suggest that the three-dimensional structures of the two lectins are likely to be very similar. Moreover, favin appears to be even more closely related in primary structure and sugar specificity to the lectins from pea and lentil, raising the possibility that all of these lectins may have structures that resemble Con A. Some of these similarities may also extend to the lectins from soybean, peanut, and red kidney bean, which have different sugar specificities but share sequence homologies with the favin beta chain.

Combined partial acid hydrolysis and electrospray ionization-mass spectrometry for the structural determination of oligosaccharides

A general oligosaccharide acid hydrolysis method, amenable to electrospray ionization mass spectrometry (ESI-MS), is described that allows for hydrolysis of glycosidic bonds for both hexose- and N-acetylhexosamine-containing oligosaccharides. The partial acid hydrolysis of oligosaccharides is obtained by using an acid-exchange resin as the acid catalyst. A ladder sequence of the glycan is produced in solution that is directly analyzed by ESI tandem mass spectrometry, employing both ion trap and Fourier transform ion cyclotron resonance mass spectrometers, to provide sequence and linkage information. Unlike traditional acid hydrolysis procedures, there is minimal degradation of monosaccharide residues or deacetylation of N-acetylhexosamines by employing this technique. It is further demonstrated that the stereochemistry of the released monosaccharides and the anomeric configuration within disaccharides is determined by direct derivatization of the hydrolysate with Zn(dien)-Cl2 followed by ESI-MS/MS.

Characterization of the high-affinity oligosaccharide-binding site of the 205-kDa porcine large granular lymphocyte lectin, a member of the leukocyte common antigen family

Membrane lectins of mammalian large granular lymphocytes are thought to be important receptors in their non-major-histocompatibility complex-restricted activation. A triantennary desialylated oligosaccharide has been reported as the most effective triggering structure [Pospísil M., Kubrycht J., Bezouska K., Táborský O., Novák M. & Kocourek J. (1986) Immunol. Lett. 12, 83-90] while its cell surface receptor has recently been identified in pig natural killer cells as a 205-kDa membrane lectin resembling the proteins of the leukocyte common antigen family (LCA). In this study we have prepared 4-azidophenyl (photoactivatable) and 4-hydroxyphenyl (radio-iodinatable) derivatives of triantennary oligosaccharides by a new procedure which allows the natural conformation of the N-glycosidic linkage between the oligosaccharide and the respective labeling group to be retained. We used these high-affinity ligands to investigate the oligosaccharide-combining site of the 205-kDa lectin. Photoaffinity labeling of the whole cells and solubilized proteins confirmed that a 205-kDa polypeptide constitutes the major cell-surface calcium-independent receptor for triantennary oligosaccharides in pig lymphocytes. Isolation and manual sequencing of two ligand-labeled and eleven other peptides proved that the 205-kDa lectin represents a member of the LCA family expressing exons 4 and 6 during alternative splicing and that the high-affinity binding site is localized in the N-terminal 70-kDa extracellular domain. Binding studies with radiolabeled oligosaccharides and the above carbohydrate-recognition domain subjected to various chemical and enzymatic treatments indicated that the binding of oligosaccharides might be significantly modulated by sialylated O-glycosidically linked lineage-specific carbohydrate epitopes localized within this domain. Affinity chromatography of LCA isolated by conventional methods on immobilized oligosaccharides revealed that only a fraction of these cell-surface glycoproteins expressed high-affinity binding sites for the oligosaccharide ligands. Thus, N-linked oligosaccharide moieties of cell-surface glycoproteins seem to represent possible ligands of LCA that may be important in intercellular adhesion and oligosaccharide-mediated activation of lymphocytes.

Localization and characterization of the carbohydrate-binding site of the porcine lymphocyte mannan-binding protein

Mannan-binding proteins found in the liver and serum of several vertebrate species are supposed to play an important role in the intracellular transport of glycoproteins, as well as in several protective reactions including complement activation and elimination of various pathogens. To study these protective functions at molecular level it is necessary to understand the fine oligosaccharide specificity and mutual relation among various forms of these soluble lectins. We have isolated mannan-binding protein as peripheral membrane proteins of porcine lymphocytes. This lectin was purified to homogeneity and shown to possess many properties in common with the well studied rat liver proteins (mol. mass, subunit composition and general organization of the molecule). Binding studies performed with three series of defined oligosaccharides (high mannose, hybrid type, and complex) on native lectin molecules as well as isolated carbohydrate-binding domains revealed distinctive features of this mannan-binding protein, including its impaired ability to bind the oligosaccharide ligand after reduction and decyclization at core N-acetyl-D-glucosamine 1.

Structure of N-linked oligosaccharide chains in the triple-helical domains of human type VI and mouse type IV collagen

Asparagine-linked oligosaccharides were liberated from pepsin-treated type VI collagen and the 7S domain of type IV collagen by hydrazinolysis and their structures analysed by exoglycosidase treatment. The major component in both proteins was complex biantennary oligosaccharide being partly modified by the addition of fucose and sialic acid residues. The 7S domain contained in addition distinct amounts of truncated biantennary structures lacking one or two beta-galactose residues and a minor triantennary structure. Carbohydrate analysis indicated that all of the N-linked and 80-90% of the O-linked acceptor sites are occupied. The lack of galactosamine content in both collagens showed the O-linked oligosaccharides were only those attached to hydroxylysine and not to serine or threonine. The high carbohydrate density along both triple helical domains is discussed with regard to their limited ability to form lateral aggregates.

Purification and characterization of biotin-binding protein II from chicken oocytes

BBP-II, the major biotin-binding protein from chicken oocytes, was purified 12,000-fold with a 22% yield. The purification procedure includes butan-1-ol extraction of yolk lipids, phosphocellulose chromatography of the water-soluble proteins, DEAE-cellulose chromatography at pH 7.4 and hydroxyapatite column chromatography. Final purification was obtained by using a second DEAE-cellulose column chromatography at pH 6.0. BBP-I activity separated from BBP-II activity during elution from the first DEAE-cellulose column. Purified BBP-II was homogeneous on both polyacrylamide-gel electrophoresis and SDS/polyacrylamide-gel electrophoresis under conditions that would detect a 1% impurity. The subunit Mr determined from SDS/polyacrylamide-gel electrophoresis was 18,200 (72,600 for tetramer), which compares favourably with an Mr value of 17,300 (69,100) calculated from the amino acid analysis. A single precipitin line formed when rabbit antiserum to the protein was directed against a crude chicken egg-yolk sample. BBP-II purified by this procedure lacked carbohydrate and phosphate, was stable indefinitely when frozen, and was quite stable at room temperature. The N-terminal amino acid sequence showed polymorphism at three positions in the first 23 residues and was about 45% identical with the N-terminal 22 residues of avidin. Antiserum to BBP-II cross-reacted with BBP-I and similar proteins in the yolk of eggs from various birds and alligator as judged by immunodiffusion and enzyme-linked immunosorbent assays. No cross-reaction was observed with chicken egg-white by either of these methods.

Urinary proteoglycan degradation product excretion in patients with rheumatoid arthritis and osteoarthritis

The excretion of sugar components of glycosaminoglycans in the urine was investigated in 19 healthy controls, 27 patients with rheumatoid arthritis, and 24 with osteoarthritis. Both groups of patients excreted significantly more glucosamine, galactosamine, and mannose than the controls. The total uronic acid excretion, also, was higher in the two groups than in the healthy subjects. The possibility of using this method for the long term follow up of rheumatoid arthritis and osteoarthritis and the response to treatment is discussed.

Riboflavin-binding protein from reptiles: a comparison with avian riboflavin-binding proteins

1. Riboflavin-binding protein (RBP) has been isolated for the first time from reptilian sources. 2. RBP from eggs of Python molurus (Indian python) and Chrysemys picta (painted turtle) has been isolated and compared to RBP from Gallus gallus domesticus (chicken), a well-characterized protein, and a newly isolated RBP from Cairina moschata (Muscovy duck). 3. Each of the proteins is phosphorylated and glycosylated. 4. The ratio of riboflavin binding to protein is 1:1 and the KD for each protein is between 1-3 nM. 5. The mol. wts, different for each species, range from 30,000-40,000, with the reptilian proteins being approx. 10,000 larger than the avian proteins.

On the macromolecular composition of the zona pellucida from porcine oocytes

The chemical and immunological relation between the glycoprotein components of the pig oocyte zona pellucida resolved by two-dimensional polyacrylamide gel electrophoresis was investigated. After disulfide bond reduction, four microheterogeneous glycoprotein components with apparent molecular weights of 25K, 55K, 65K, and 90K were resolved. When disulfide bonds were left unreduced, two microheterogeneous glycoprotein components were resolved with apparent molecular weights of 55K and 90K. Actin was present, but as a contaminant of the zona pellucida rather than as a true component. The structural relation of these components was investigated using deglycosylation with trifluoromethane-sulfonic acid, limited proteolysis with Staphylococcus aureus V8 protease, amino acid and carbohydrate composition analyses, sequence analysis, and monoclonal antibodies. The 25K and 65K components comigrated with the 90K component when disulfide bonds were not reduced. When the intermolecular disulfide bonds crosslinking the two components were reduced, the 25K and 65K components behaved independently. The 25K and 65K components were derived from the 90K glycoprotein family by proteolysis. The 25K component originated from the C-terminal end, and the 65K component from the N-terminal end of the 90K glycoprotein. The 55K component was composed of two chemically and antigenically distinct glycoproteins, termed 55K alpha and 55K beta, that electrophoretically comigrated. The N-terminal amino acid of the 55K alpha family was blocked. The 55K beta family had an N-terminal amino acid sequence of Asp-Val-Pro-Thr-Ile-Gly-Leu-Ser-X-Ala-Pro-Thr. Thus, the two to four electrophoretic components of the zona pellucida observed on gel electrophoresis are derived from three glycoprotein families.

Antibody response to teichoic acid and peptidoglycan in Staphylococcus aureus osteomyelitis

An enzyme-linked immunosorbent assay was used to evaluate the immunoglobulin G (IgG) response to Staphylococcus aureus crude teichoic acid (TA) and peptidoglycan (PG) in both rabbits and patients with osteomyelitis. In rabbits with experimental S. aureus osteomyelitis, elevated levels of IgG to TA were present in 13/18 (72%) of the serum samples obtained at 4 and 10 weeks postinfection. In contrast, only 5/18 (28%) of these sera were found to be positive for antibodies to PG. Of a total of 39 patients with confirmed S. aureus osteomyelitis (11 acute, 28 chronic), IgG to TA was elevated in 17 (44%), whereas antibodies to PG were found to be increased in only 1 (3%). Cross-reacting antibodies to S. aureus TA were detected in only 1/18 (6%) of the patients with osteomyelitis caused by organisms other than S. aureus. These studies indicate that IgG to TA is more prevalent than IgG to PG in patients with staphylococcal osteomyelitis. Although these results are encouraging, a larger number of patients is required for an adequate evaluation of the TA enzyme-linked immunosorbent assay for the diagnosis and management of suspected S. aureus osteomyelitis.

Sulfated glycosaminoglycans in rat lung tissue during experimental silicotic fibrosis

The biosynthesis of sulfated glycosaminoglycans (GAG) was studied in healthy and fibrotic lung tissue (experimental silicosis). Male rats received a single intratracheal instillation of 25 mg quartz dust (DQ 12) in 0.7 ml saline and were sacrificed at days 15, 30, 90, 150 and 240 after the insult. GAGs were labeled in vivo by i.p. (intraperitoneal) administration of [35S] sulfate. The concentration of GAGs in delipidated dry tissue was unaffected, however, the uptake of [35S] sulfate into silicotic lung tissue was significantly higher than in controls. Identification of sulfated GAGs isolated from pooled samples by DEAE-cellulose chromatography was achieved by electrophoresis and chondroitinase digestion. The most marked change in the label distribution among individual GAGs occurred with regard to dermatan sulfate. The fraction of label in dermatan sulfate was elevated in silicotic lung.

Isolation and characterization of a lectin from the cortical granules of Xenopus laevis eggs

A cortical granule lectin was isolated from eggs of the South African clawed toad Xenopus laevis. The lectin was released from the cortical granules by activation of dejellied eggs with the Ca2+ ionophore A23187. The lectin was purified by affinity chromatography with its natural ligand, the egg jelly coat, chemically coupled to a Sepharose matrix. The purified lectin was homogeneous by the criteria of isoelectric focusing (pI = 4.6), immunodiffusion, and immunoelectrophoresis but existed in two different molecular weight isomers as determined by sedimentation velocity ultracentrifugation and disc gel electrophoresis. Molecular weights of the isomers were determined by ultracentrifugation, disc gel electrophoresis, and gel filtration and found to be 539,000 and 655,000. Chemically, the lectin was a metalloglycoprotein, composed of 84.0% protein, 15.8% carbohydrate, and 0.19% calcium. No unusual types or amounts of amino acids were present. The carbohydrate moiety was composed of fucose, mannose, galactose, glucosamine, galactosamine, and sialic acid. The monosaccharide specificity of the lectin was investigated with the sugar inhibition of the precipitin reaction in gels. The lectin was specific for D-galactosyl sugars with the configuration at carbon atoms 2-4 of primary importance.

Isolation of the zona pellucida and purification of its glycoprotein families from pig oocytes

The isolation of the porcine zona pellucida, the glycoprotein envelope surrounding the mammalian oocyte, and the purification of its glycoprotein families is described. The zona pellucida was prepared from oocytes isolated from pig ovaries using a razor blade device and sieving procedures with Teflon or nylon screens. In 6-7 man h, the zona pellucida from 5 X 10(5) oocytes was obtained yielding 12 mg protein and 2.2 mg carbohydrate. The absorptivity of heat solubilized and filtered zona pellucida was A1%280 nm, 1 cm = 10.8. The four glycoprotein families of the zona pellucida were purified by two-dimensional polyacrylamide gel electrophoresis and electrophoretic elution. The electrophoretic purity of these families was greater than 90%. The protein and carbohydrate content and the amino acid and monosaccharide compositions of each of the glycoprotein families were determined.

Purification, identification and characterization of chicken C1q, a subcomponent of the first component of complement

A component, having the equivalent haemolytic activity to that of human complement subcomponent C1q, was purified by a combination of precipitation with EGTA, gel filtration, ion exchange and adsorption chromatography from chicken serum. Yields ranged from 8 to 15 mg/litre of serum. The finally purified preparation generates full Cl haemolytic activity when assayed with human complement subcomponents C1r and C1s, and have been identified as chicken C1q. The molecular weight of undissociated C1q, as estimated on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS), is 504,000. Under dissociating but non-reducing conditions, the C1q was shown to consist of 2 subunits having molecular weights of 52,700 and 51,200 in a molar ratio of 2:1. On reduction, the 52,700 molecular weight subunit gave chains with molecular weights of 25,900 and 24,800 in equimolar ratio, and the 51,200 molecular weight subunit decreased to 24,800. The C1q contains hydroxyproline, hydroxylysine, a high percentage of glycine and approximately 7% carbohydrate. Collagenase digestion of C1q caused a rapid loss of haemolytic activity and produced much smaller peptide fragments.

Identification and characterization of mouse small intestine mucosal receptors for Escherichia coli K-12(K88ab)

Adhesion of 3H-labeled Escherichia coli K-12(K88ab) to CD-1 mouse small intestine mucus and brush border preparations, immobilized on polystyrene, was studied. E. coli K12(K88ab) was shown to adhere readily to either crude mucus or brush border preparations, but not to bovine serum albumin. In contrast, the nearly isogenic E. coli K-12 strain, i.e., lacking the K88ab plasmid, did not bind well to either mucus, brush borders, or bovine serum albumin. The adhesion of E. coli K-12(K88ab) to both mucus and brush borders required pilus expression (i.e., growth at temperatures greater than 18 degrees C) and was inhibited by pretreatment of either mucus or brush borders with trypsin, pronase, or sodium metaperiodate and by the presence of D-galactosamine. Crude mucus was fractionated by gel filtration, and the proteins in receptor-containing fractions were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Separated proteins were Western blotted to nitrocellulose. Adhesion of 35SO4-labeled E. coli K-12(K88ab) and 35SO4-labeled E. coli K-12 to Western blots followed by autoradiography revealed two E. coli K-12(K88ab)-specific mucus receptor proteins (57 and 64 kilodaltons). Brush borders contained the same two receptor proteins present in mucus and an additional 91-kilodalton receptor protein.

Carbohydrate-structure-dependent recognition of desialylated serum glycoproteins in the liver and leucocytes. Two complementary systems

Oligosaccharides with four different types of branching were prepared from purified human transferrin, alpha 2-macroglobulin, caeruloplasmin and alpha 1-acid glycoprotein and labelled with NaBH3 3H. Binding of these oligosaccharides to rat liver plasma membrane, rat leucocytes, pig liver plasma membranes and pig leucocyte plasma membranes was investigated. A striking dependence of binding on oligosaccharide branching was observed. The values of apparent association constants Ka at 4 degrees C vary from 10(6) M-1 (biantennary structure) to 10(9) M-1 (tetra-antennary structure) in the liver, whereas in the leucocytes the Ka values were found to be of reversed order, from 1.8 X 10(9) M-1 for biantennary to 2.2 X 10(6) M-1 for tetra-antennary structures. The binding is completely inhibited by 150 mM-D-galactose, but 150 mM-D-mannose has almost no effect on binding. Leucocyte plasma membranes bind preferentially 125I-asialoglycoproteins with biantennary oligosaccharides, thus completing the specificity pattern of the hepatic recognition system for desialylated glycoproteins. Possible physiological roles of these two complementary recognition systems under normal and pathological conditions are discussed.

Adhesion of a human fecal Escherichia coli strain to mouse colonic mucus

Escherichia coli F-18 isolated from the feces of a healthy human is an excellent colonizer of the CD-1 mouse colon. In the present investigation, adhesion of E. coli F-18 to CD-1 mouse colonic mucus and bovine serum albumin (BSA), immobilized on polystyrene, was studied. Adhesion of E. coli F-18 to mucus was two- to sixfold greater than to either BSA or polystyrene. E. coli F-18 lipopolysaccharide specifically blocked adhesion of E. coli F-18 to mucus and mimicked adhesion of E. coli F-18 to mucus, BSA, and polystyrene. Purified capsule also blocked adhesion of E. coli F-18 to mucus, but this inhibition was found to be entirely nonspecific. The specific E. coli F-18 receptor in mucus appeared to be a glycoprotein, containing sugars normally found in mucins and having a maximum molecular weight of between 1.25 X 10(5) and 2.5 X 10(5).

Characterization of polysaccharides of the eggs and adults of Hymenolepis diminuta

Polysaccharides and other complex carbohydrates were released by proteolysis of the chloroform-methanol insoluble residue of 10 day-old worms and eggs of Hymenolepis diminuta. Gas-liquid chromatographic analysis of alditol acetate derivatives of monosaccharides released from the polysaccharides by hydrolysis revealed that in the 10 day-old worm, glucose was the most abundant sugar, followed by galactose, glucosamine, galactosamine, fucose and possibly rhamnose. Mannose was least abundant and xylose was absent. In the egg, glucose and galactose were equally abundant, followed by the same sugars found in 10 day-old worms, and xylose was present. Uronic acid was detected in both fractions by specific chemical tests. None of the saccharide material from eggs and worms was susceptible to degradation by Streptomyces hyaluronidase, chondroitinase AC, and slightly susceptible to chondroitinase ABC, as shown by electrophoretic analysis on composite 2.2% acrylamide-agarose slab gels and 4.5/12.5% polyacrylamide gels before and after enzymatic treatment. One of the gel-separable bands, however, was degradable by both nitrous acid and Flavobacterium heparinase. Both bands from eggs were degradable by nitrous acid. These results suggest that eggs contain heparin and/or heparan sulfate and perhaps dermatan sulfate and that 10 day-old worms also have these polyglycans but possibly not chondroitin sulfate or hyaluronic acid.

Isolation and some structural analyses of a proteodermatan sulphate from calf skin

A proteodermatan sulphate was isolated from 0.15 M-NaCl and 0.45 M-NaCl extracts of newborn-calf skin. The proteoglycan was separated from collagen and hyaluronic acid by precipitation with cetylpyridinium chloride and CsCl-density-gradient centrifugation. Further purification was performed by ion-exchange, affinity and molecular-sieve chromatography. The proteoglycan bound to concanavalin A-Sepharose in 1 M-NaCl. It gave a positive reaction with periodic acid/Schiff reagent and contained 8.3% of uronic acid. The dermatan sulphate, the only glycosaminoglycan component, was composed of 74% iduronosylhexosamine units and 26% glucuronosylhexosamine units. The Mr was assessed to be 15000-20000 by gel chromatography. The core protein was found to be a sialoglycoprotein that had O-glycosidic oligosaccharides with N-acetylgalactosamine at the reducing termini. The molar ratio of oligosaccharide chains to dermatan sulphate was approx. 3:1. From these results the proposed structure of proteodermatan sulphate is: one dermatan sulphate chain (average Mr 17500), three O-glycosidic oligosaccharide chains and probably N-glycosidic oligosaccharide chain(s) bound to one core-protein molecule (Mr 55000).

Structure of the mannose-rich oligosaccharide chains of concanavalin A-binding glycopeptides derived from beef brain glycoproteins

A neutral, mannose-rich, concanavalin A (Con A)-binding glycopeptide fraction was obtained by proteolytic digestion of defatted beef brain tissue. Hydrazinolysis followed by gel filtration of the reaction products provided three oligosaccharides. A portion of each oligosaccharide was treated by exhaustive digestion with alpha-mannosidase. Another portion was subjected to selective acetolysis of Man alpha 1 leads to 6Man linkages, providing two fragments that were recovered by gel filtration. The structure of the intact oligosaccharides, as well as the fragments obtained by selective acetolysis and enzymatic treatment, were resolved by gas-liquid chromatographic-mass spectrometric analysis. The structures of the three oligosaccharides were: (a) Man alpha 1 leads to 2Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man alpha 1 leads to 6(Man alpha 1 leads to 2Man alpha 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4-N-acetylglucosamine (GlcNAc)beta 1 leads to 4N-acetylglucosaminitol (GlcOLNAc); (b) Man alpha 1 leads to 2Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man alpha 1 leads to 6(Man alpha 1 leads to 2Man alpha 1 leads to 3)-Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcOLNAc; and (c) Man alpha 1 leads to 6(Man alpha 1 leads to 3) Man alpha 1 leads to 6(Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc-beta 1 leads to 4GlcOLNAc. These structures account for 15-20% of the glycoprotein-carbohydrate of whole beef brain and most of the oligosaccharides that demonstrate a high affinity for Con A. In view of the large number of Con A-binding glycoproteins in brain tissue, it appears that many of these different glycoproteins must contain structurally identical oligosaccharides.

O-antigen conversion in Pseudomonas aeruginosa PAO1 by bacteriophage D3

The lysogenization of Pseudomonas aeruginosa PAO by phage D3 results in derivatives which are resistant to superinfection by phage D3c by virtue of the fact that homologous phage cannot adsorb to these cells. The serologically and morphologically unrelated phage E79 showed a markedly decreased adsorption rate to the lysogen PAO(D3). Since both of these phages are lipopolysaccharide specific, these results suggested lysogenic conversion of the phage receptor. The lipopolysaccharide was extracted from strain PAO by the hot phenol-water technique, but this procedure was ineffective with PAO(D3). We developed a technique involving cold trichloroacetic acid extraction, followed by ultracentrifugation, digestion of the high-speed pellet with proteinase K, and ultimate purification on CsCl step gradients. The lipopolysaccharide from the wild type had inactivating activity against D3 and E79, whereas that from PAO(D3) inactivated neither. Chromatographic analysis indicated that the convertant lipopolysaccharide was smooth, and quantitative chemical analyses of the two preparations showed no differences in the level of the major fatty acids, amino compounds, or neutral sugars. On the other hand, sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the side chains had a decreased migration rate through the gel matrix. The application of 1H and 13C nuclear magnetic resonance spectroscopic analysis revealed that the PAO side chain is chemically identical to that of serotype O:2a,d, containing 2,3-(1-acetyl-2-methyl-2-imidazolino-5,4)-2,3-dideoxy-D-mannuronic acid, 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid, and 2-acetamido-2,6-dideoxy-D-galactose (D-fucosamine). The molecular basis of the conversion event was (i) the introduction of an acetyl group into position 4 of the fucosamine residue and a change in the bonding between trisaccharide repeating units from alpha 1 leads to 4 to beta 1 leads to 4.

Detection of neutral and aminosugars from glycoproteins and polysaccharides as their alditol acetates

A new method for the preparation and separation of alditol acetates from neutral sugars has been applied to aminosugars. Reduced aminosugars were rapidly acetylated using 1-methylimidazole as the catalyst without removal of borate formed during reduction. The alditol acetates were separated by glass capillary gas chromatography on Silar 10C. The alditol acetates of aminosugars had retention times much longer than those of neutral sugars. However, the alditol acetates of the deamination products of aminosugars had shorter retention times and were resolved from those of neutral sugars. This method was used for the simultaneous detection of neutral and aminosugars in acid hydrolysates of chitin and the glycoproteins, ovalbumin and peroxidase.

Characterisation of beta 1-anticollagenase from human plasma and its reaction with polymorphonuclear leukocyte collagenase by disulfide/thiol interchange

A beta 1-serum component, beta 1-anticollagenase, capable of inhibiting various mammalian tissue collagenases, was isolated from human plasma by gel filtration, affinity chromatography and ion-exchange chromatography. The inhibitor contains 1-2 free sulfhydryl groups, which are a prerequiste for inhibitory activity and for binding to the thiol-Sepharose affinity support. Alkylation of beta 1-anticollagenase by iodoacetamide blocks inhibitory activity. The inhibitor was purified to apparent homogeneity and exhibited a Mr = 30500 determined by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The amino acid and carbohydrate composition was determined. According to its composition and the isoelectric focussing beta 1-anticollagenase is an acidic protein with an isoelectric point of 5.6. Inhibition of human leukocyte collagenase proceeds in a strong 1 : 1 stoichiometric reaction. The mechanism of this association takes place by a disulfide/thiol interchange reaction as has been previously indicated for human leukocyte collagenases in forming the latent enzyme [Macartney, H. W. and Tschesche, H. (1980) FEBS Lett. 119, 327-332]. The beta 1-anticollagenase--leukocyte-collagenase complex (latent enzyme) is activatable by disulfide-containing compounds such as cystine, oxidised glutathione, insulin, relaxin, trypsinogen and others, but not by 179,203-di(S-carboxymethyl)trypsinogen, or its trypsin derivative. Compounds containing inaccessible disulfide bonds, e.g. chymotrypsin, or sulfhydryl groups, e.g. D-penicillamine, do not activate the complex. Activation is, however, easily obtained with the oxidised-glutathione-generating system myeloperoxidase/H2O2/glutathione as was previously demonstrated for the human leukocyte latent collagenase activatable in a phagocytosis-simulated respiratory burst [Tschesche, H. and Macartney, H. W. (1981) Eur. J. Biochem. 120, 183-190].

Effect of D-glucosamine on the content and synthesis of UDP-sugars and plasma membrane associated carbohydrates in chicken liver and hepatoma Mc-29

1. Comparative studies on the effect of D-glucosamine on the synthesis of UDP-sugars and on the incorporation rate of [14C]glucose into neutral sugars, sialic acid and glucosamine isolated from chicken liver and hepatoma Mc-29 plasma membranes have been carried out. 2. The influence of D-glucosamine on the activity of microsomal UDP-N-acetylglucosamine: glycoprotein N-acetylglucosaminyltransferase to lipid (dolichol monophosphate) and to protein acceptor was studied too. 3. It has been shown that D-glucosamine provokes alterations in the content and synthesis of UDP-sugars and it is an inhibitor of the glycosylation processes. An inhibitory effect of this sugar analog on the N-acetylglycosaminyltransferase has been established.

GLC-mass fragmentographic determination of mannitol and sorbitol in plasma

A GLC-mass fragmentographic method was developed for the simultaneous determination of mannitol and sorbitol as their n-butyldiboronate derivatives in plasma. The plasma sample was deproteinized, and the subsequent supernatant was concentrated to dryness; the resulting residue was then dissolved in pyridine containing n-butylboronic acid to allow derivation. An aliquot of this solution was injected into the gas chromatograph-mass spectrometer and analyzed by a selected-ion monitoring method using galactitol as the internal standard. Detection was limited to 20 ng/0.1 ml of plasma for both mannitol and sorbitol. A rapid, precise, and sensitive assay for the determination of mannitol and sorbitol in plasma was established.

The metabolism and structure of phosphoglycoproteins in rat brain

Glycoproteins that contain phosphohexosyl groups were found to be present in the myelin- and synaptosomal-enriched fractions as well as in the microsomes of rat brain. The kinetics of flow of intraperitoneally injected [32P]phosphate suggests that the phosphate is enzymatically added in structures found in the microsomal fraction. The newly synthesized phosphoglycoproteins then appear in the soluble fraction of the synaptosomes and in the cytosol, prior to incorporation into the membranes of the synaptosomes and myelin. Phosphoglycopeptides recovered from the phosphoglycoprotein contain 3 Mannose units per N-acetylglucosamine residue; one of the mannose residues is phosphorylated. [13C]NMR studies indicate that the phosphoglycopeptides contain a chitobiose group and more than four sugar residues. Thus, the phosphomannoglycopeptides from rat brain contain an average of 2 N-acetylglucosamine, 6 mannose, and two phosphate moieties per oligosaccharide chain. Enzymatic treatment with alpha-mannosidase failed to remove the phosphomannose, although some mannose residues were released. Thus, the phosphorylated mannose is not removed by the glycosidase and terminal nonphosphorylated mannose residues are present in the oligosaccharide. The phosphate residues are removed by treatment with alkaline phosphatase.

Carbohydrate compositional effects on tissue distribution of chicken riboflavin-binding protein

Riboflavin-binding proteins (RBP) purified from chicken egg white, yolk and the serum of laying hens differ in their carbohydrate compositions reflecting tissue-specific modifications of a single gene product. All three are complex glycoproteins having more than twice as many N-acetylglucosamine residues (greater than 12) as mannose residues (approx. 6). Egg white RBP is distinctive in having only one sialic acid and two galactose residues. Serum RBP contains approx. five sialic acid and seven galactose residues. In addition there is one residue of fucose. The carbohydrate composition of yolk RBP indicated the hydrolysis, respectively, of one, one, two and 3 residues of sialic acid, fucose, galactose, and N-acetylglucosamine from its precursor, serum RBP. The effect of these differing levels of glycosylation on plasma clearance, ovarian uptake and tissue distribution of 125I-labeled riboflavin-binding proteins in laying hens were compared. 2 h after intravenous injection, 19% of the egg white RBP, 29% of the yolk RBP, and 37% of the serum RBP remained in circulation. The kinetics of plasma clearance was distinctly biphasic for each of the radioiodinated proteins. The initial rapid-turnover component (t1/2 = 13 min) ranged from 27% of the serum RBP sample to 48% of the egg white RBP sample. The remaining slow-turnover components were cleared with half-lives of 81 min (egg white RBP), 101 min (yolk RBP), and 121 min (serum RBP). 16 h after injection, only 4% of the egg white RBP was deposited in the yolk of developing oocytes while about 12% of the serum RBP and yolk RBP was deposited. This highly significant difference is apparently due to preferential, carbohydrate-dependent clearance of egg white RBP by the liver rather than preferential uptake of serum and yolk RBP by the ovarian follicle. We find no evidence for carbohydrate-directed uptake of riboflavin-binding protein by the ovarian follicle.

Distribution of macromolecular components in human dermal connective tissue

Normal human skin was sliced into five horizontal layers and distribution of type I and type III collagens, glycosaminoglycans, and non-collagenous glycoprotein(s) among the five layers was analyzed. No remarkable differences in the relative contents of type I and type III collagens and noncollagenous glycoprotein(s) were detected among the five layers. However, glycosaminoglycan content was higher in the upper layers than in the lower and the ratio of hyaluronic acid to dermatan sulfate was also higher in the upper layers. These results are compared and discussed with our previous data on calf skin.

Distribution of macromolecular components in calf dermal connective tissue

Distribution of type I and type III collagens, glycosaminoglycans and non-collagenous glycoprotein(s) in calf skin has been investigated in five horizontally sliced layers of 250 microns thickness from the surface to the bottom. The upper dermis (the top three layers) consisting of fine collagen fibers had a higher ratio of hyaluronic acid/dermatan sulfate than the lower layers where coarse collagen fibers are mainly located. The ratios of total glycosaminoglycans/collagen and glycoprotein(s) collagen were higher in the upper dermis, while dermatan sulfate/collagen remained constant throughout the dermis. Relative content of type III collagen/total collagen (type I + III collagens) was also higher in the upper dermis. Possible involvement of these macromolecular constituents in collagen fibrillogenesis in vivo is also discussed.