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J C Michalski

Publications and source records attributed to J C Michalski.

At least 73 records · Page 4Linked to original sources
PubMed1989

Complete analysis of the 1H- and 13C-NMR spectra of four blood-group A active oligosaccharides.

The fully assigned 1H and 13C-NMR spectra of four group A oligosaccharides by use of multiple-relayed, coherence-transfer chemical-shift-correlated spectroscopy (multiple-RELAY-COSY) and 1H-/13C-correlation spectroscopy are reported. These analyses were performed on the following compounds: III-A; GalNAc alpha 1-3[Fuc alpha 1-2]Gal: VI-A; GalNAc alpha 1-3[Fuc alpha 1-2]Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal: VII-A-1; GalNAc alpha 1-3[Fuc alpha 1-2]Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-1Glycerol: VII-A-2; GalNAc alpha 1-3[Fuc alpha 1-2]Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4Glc.

ABO Blood-Group System↗
PubMed1989

Assignment of the 1H- and 13C-NMR spectra of eight oligosaccharides of the lacto-N-tetraose and neotetraose series.

The assignment of the 13C- and 1H-NMR spectra of eight oligosaccharides of the lacto-N-tetraose and neotetraose series was obtained from homonuclear and heteronuclear correlation spectroscopy. These analyses were performed on the following compounds: 1. Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc; 2. NeuAc alpha 2-3Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc; 3. Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 4. NeuAc alpha 2-3Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 5. NeuAc alpha 2-3Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4Glc; 6. Fuc alpha 1-2Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 7. Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc; 8. NeuAc alpha 2-6Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc.

Carbohydrate Conformation↗
PubMed1989

Primary structure of human milk nona- and decasaccharides determined by a combination of fast atom bombardment mass spectrometry and 1H-/13C-nuclear magnetic resonance spectroscopy. Evidence for a new core structure, iso-lacto-N-octaose.

The structure of a nonasaccharide and of two decasaccharides isolated from human milk has been investigated by using methylation, fast atom bombardment mass spectrometry and 1H-/13C-nuclear magnetic resonance spectroscopy. The structures of these oligosaccharides were: trifucosyllacto-N-hexaose; Fuc alpha 1-2Gal beta 1-3(Fuc alpha 1-4)GlcNAc beta 1-3[Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6]Gal beta 1-4Glc, difucosyllacto-N-octaoses; Gal beta 1-3(Fuc alpha 1-4)GlcNAc beta 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6[Gal beta 1-3GlcNAc beta 1-3]Gal beta 1-4Glc and Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6[Fuc alpha 1-3 Gal beta 1-3GlcNAc beta 1-3]Gal beta 1-4Glc. The two decasaccharides possess a new type of core structure proposed to be named iso-lacto-N-octaose.

Carbohydrate Conformation↗
PubMed1989

Sequential 1H and 13C resonance assignments for an octa- and decasaccharide of the N-acetyllactosamine type by multiple-step relayed correlation and heteronuclear correlation nuclear magnetic resonance.

400 MHz 1H-NMR and 100 MHz 13C-NMR spectra of a neutral octasaccharide and of a disialyldecasaccharide of the N-acetyllactosamine type were studied. The resonance assignments were made by combining multiple-relayed coherence-transfer chemical-shift-correlated spectroscopy (multiple-RELAY-COSY) and 1H/13C-shift correlated 2D experiments. The complete analysis of the 1H and 13C spectra was performed.

Amino Sugars↗
PubMed1989

[Biochemical and ultrastructural study of two familial cases of Winchester syndrome].

Two new familial cases of Winchester syndrome with the characteristic features allowed to be more explicit on a few data of this syndrome. As reported in a previous paper an abnormal oligosaccharide was detected in urine of patients but the pathological significance of this oligosaccharide must be discussed and its finding in patients with Winchester syndrome does not lead to further elucidation of the aetiology of this condition. Cultured fibroblasts were obtained from a skin biopsy performed in thickened area. These cells had a normal level of the hydrolases studied whereas they showed ultrastructural abnormalities with numerous secondary lysosomes and pseudomyelinic figures.

Cells, Cultured↗
PubMed1988

Lysosomal catabolic pathway of N-glycosylprotein glycans.

In vitro study of the initiation steps of catabolism of N-glycosylproteins in rat liver lysosomes has led to the evidence that the degradation of the carbohydrate chain is an ordered and bi-directional phenomenon: 1) The first one starts at the reducing terminus, immediately follows the degradation of the peptidic backbone by proteases and involves a serial reaction of 3 enzymes, respectively, 1) an alpha-L-fucosidase, 2) an aspartylglucosaminidase, and 3) an acidic 'oligosaccharide specific' endo-N-acetyl-beta-D-hexosaminidase, that we propose calling endo-chitobiase. 2) The second one is the commonly admitted sequential recurrent degradation by exoglycosidases. This process explains the presence of oligosaccharides sharing a single terminal reducing N-acetylglucosamine residue in human lysosomal storage diseases. Using a model glycoasparagine as a substrate, we followed the above mentioned hydrolysis reactions by 1H NMR spectroscopy. The kinetic data revealed a rapid hydrolysis of the substrate via pathway 1 prior to the action of exoglycosidases. Moreover, the latter act at different rates on the different antennae of the substrate.

Animals↗
PubMed1987

Catabolism of N-glycosylprotein glycans: evidence for a degradation pathway of sialylglyco-asparagines resulting from the combined action of the lysosomal aspartylglucosaminidase and endo-N-acetyl-beta-D-glucosaminidase. A 400-MHz 1H-NMR study.

A mixture of sialylglycoasparagines and sialylglycopeptides was successively incubated with lysosomal extracts, at two pH values, first at pH 7.5 and then at pH 4. The 1H-NMR analysis of the sialyloligosaccharides released during the enzymatic digestion demonstrates the sequential action of aspartylglucosaminidase and an endo-N-acetyl-beta-D-glucosaminidase which release sialyloligosaccharides identical to the reference sugars isolated from the urine of patients suffering from sialidosis. This process represents a new catabolic pathway for N-glycosyl-proteins which may account for the appearance of the oligosaccharides stored in tissues and urine of patients suffering from lysosomal diseases.

Acetylglucosaminidase↗
PubMed1987

Structure of the monosialyl oligosaccharides derived from salivary gland mucin glycoproteins of the Chinese swiftlet (genus Collocalia). Characterization of novel types of extended core structure, Gal beta(1----3)[GlcNAc beta(1----6)] GalNAc alpha(1----3)GalNAc(-ol), and of chain termination, [Gal alpha(1----4)]0-1[Gal beta(1----4)]2GlcNAc beta(1----.).

The mucus glycoproteins, the so-called nest-cementing substance, from the salivary gland of Chinese swiftlets (genus Collocalia) are mainly constituted of sialic acid-rich O-glycosylproteins. Alkaline reductive treatment of the crude material led to the release of some neutral and numerous monosialyl and disialyl oligosaccharides. These were fractionated by gel filtration, anion-exchange chromatography, and high-performance liquid chromatography. The structures of the monosialyl oligosaccharides were established by combination of sugar and methylation analysis, fast atom bombardment-mass spectrometry, and electron impact-mass spectrometry after permethylation and 1H NMR spectroscopy (at 500 MHz). Typically, some of the monosialyl oligosaccharides appeared to possess the core structure Gal beta(1----3)[GlcNAc beta(1----6)]GalNAc alpha(1----3)GalNAc-ol. Moreover, the (1----6)-linked branch consisted of an unusual di- or trigalactosyl sequence, [Gal alpha(1----4)0-1Gal beta(1----4)Gal beta (1----4)GlcNAc beta(1----6). Thus, the most complex representatives of the monosialyl fraction from Collocalia mucin were found to be: (Formula: see text) The other compounds identified are partial structures thereof.

Animals↗
PubMed1987

Excretion of cobalamin and haptocorrin in the meconium of cystic fibrosis, premature, and control neonates.

Excretion of haptocorrin (R binder), cobalamin, and other corrinoids was studied in meconium from cystic fibrosis (n = 4), premature (n = 3), and control neonates (n = 13). Corrinoids content was 1.67 +/- 0.92 pmol/mg protein in meconium of cystic fibrosis (CF) neonates but only 0.33 +/- 0.37 and 0.48 +/- 0.47 pmol/mg protein, respectively, in that of prematures and controls. Considering its molecular mass (110,100 +/- 10,100) and its mean isoelectric point (3.67 +/- 0.20), haptocorrin remained undergraded in the meconium of CF neonates whereas it was partially degraded in the meconium of prematures and in most of the meconium from controls. Sequestration of cobalamin by undergraded haptocorrin can explain its increased excretion in CF meconium. Cobalamin-binding capacity of haptocorrin was 22.13 +/- 15.50 pmol/mg protein in CF meconium and about 400-fold lower in meconium of prematures and controls. This may correspond to a fetal intestinal hypersecretion in cases of CF.

Cystic Fibrosis↗
PubMed1987

Ganglioside storage, hexosaminidase lability, and urinary oligosaccharides in adult Sandhoff's disease.

Two adult sisters with severe spinocerebellar degeneration were deficient in hexosaminidase A and B. GM2 ganglioside storage in brain tissue obtained by autopsy from one patient was most pronounced in the cerebellum. Hexosaminidase activity in brain tissue was negligible, but fibroblasts from the second patient contained relatively high amounts of heat-labile activities of both isoenzymes. Pulse-chase experiments showed synthesis of precursor alpha- and beta-chains of hexosaminidase, maturation of the alpha-chain, but only a very small amount of mature beta-chain. These data indicate a destabilizing mutation in the beta-locus. Substrate-specific effects of this mutation were demonstrated by the urinary oligosaccharide pattern.

Adult↗
PubMed1986

Catabolism of glycoprotein glycans. Characterization of a lysosomal endo-N-acetyl-beta-D-glucosaminidase specific for glycans with a terminal chitobiose residue.

An endo-N-acetyl-beta-D-glucosaminidase active towards oligosaccharides with a reducing terminal [bis(N-acetylglucosamine)]residue has been characterized in rat liver. The primary structure of its reaction products was determined using high-resolution 1H-NMR spectroscopy. The enzyme is predominantly located in the lysosomal fraction, presents a maximum of activity at pH 3.5 and is completely inactive towards conjugated glycans, i.e. glycoproteins and glycopeptides as well as on glycoasparagines. These results support the existence of a new pathway for the degradation of glycoprotein glycans inside the lysosome. In particular, this enzymic activity may be the origin of oligosaccharides bearing a single terminal reducing N-acetylglucosamine residue which are excreted in the urine of patients with various exoglycosidase deficiencies.

Acetylglucosaminidase↗
PubMed1986

Primary structure of a new tetraantennary glycan of the N-acetyllactosaminic type isolated from human factor VIII/von Willebrand factor.

N-Glycosidically linked glycopeptides released by mild alkaline treatment of human factor VIII/von Willebrand factor (FVIII/vWF) were fractionated by serial affinity chromatography on columns of Sepharose linked to concanavalin A (ConA) and Lens culinaris agglutinin (LCA). The fraction which is not retained on ConA-Sepharose, but eluted from LCA-Sepharose contains a pure minor glycopeptide which was structurally analysed. Based on the results of methylation analysis and 500-MHz 1H-NMR spectroscopy, the following structure is proposed: (Formula: see text).

Amino Acid Sequence↗
PubMed1986

Salla disease in one non-Finnish patient.

In a 5-year-old boy, an early onset psychomotor retardation with non-progressive ataxia and without dysmorphic features, associated with lysosomal storage disease found on ultrastructural examination of the conjunctiva, led to the diagnosis of Salla disease. This was supported by a tenfold excretion of urinary free sialic acid, without abnormal oligosacchariduria or anomaly in lysosomal enzymes. This boy is a native of Southern France. Screening of urinary sialic acid has to be introduced in aetiological investigations of patients with apparently non-progressive psychomotor retardation associated with ataxia or dystonic movements.

Child↗
PubMed1986

Properties of human liver lysosomal sialidase.

Sialidase in human liver was localized predominantly in the lysosomal fraction. Microsomal and nuclear fractions contained some activity but no cytosolic enzyme could be detected. The lysosomal enzyme fraction is active with gangliosides, fetuin, mucus glycoprotein, sialyllactose and other sialyloligosaccharides. The preferred rate of enzymic hydrolysis of sialyl linkages is alpha(2-3) greater than alpha(2-6) greater than alpha(2-8) and this is governed by the Vmax values, as Km values were similar for all substrates tested. N-Acetyl-neuraminic acid is released faster than N-glycoloylneuraminic acid. Using the inhibitors N-acetyl-2-deoxy-2,3-didehydroneuraminic acid and N-(4-nitrophenyl)oxamic acid with selected substrates the existence of at least two types of sialidase activity could be demonstrated. One is active preferentially with gangliosides and sialyllactose and the other with fetuin and sialyhexasaccharides. Strong inhibition by Cu2+ and Hg2+ was found with ganglioside and sialyllactose as substrates. The presence of a sialate O-acetylesterase acting on hematoside containing N-glycoloyl-4-O-acetylneuraminic acid was established.

Enzyme Stability↗
PubMed1985

Purification of human intrinsic factor using high-performance ion-exchange chromatography as the final step.

Human intrinsic factor was purified 1430-fold from gastric juice with a yield of 75% using two steps: labile ligand affinity chromatography and high-performance ion-exchange chromatography. Intrinsic factor precipitated in the presence of specific autoantibodies and 15% sodium sulfate, had an estimated Mr of 59 000 in 5% SDS electrophoresis and could bind to the specific ileal receptor in vitro. Its carbohydrate composition could be related to N-lactosaminic and O-glycosidic chains. High-performance ion-exchange chromatography was a mild, rapid and efficient procedure to separate completely intrinsic factor from haptocorrin (another glycoprotein of gastric juice which binds cobalamin) and from other contaminating proteins.

Chromatography, Gel↗
PubMed1984

Abnormal galactoside excretion in urine of a patient with early myoclonic epileptic encephalopathy.

An abnormal carbohydrate pattern was found in urine of a patient with early myoclonic epileptic encephalopathy. Three major oligosaccharides have been isolated from the urine; structural studies including sugar analyses, methylation procedure and enzymatic hydrolysis allow us to propose the following structures: beta-Gal-(1 leads to 3)-Gal beta-Gal-(1 leads to 3)-beta-Gal-(1 leads to 3)-Glc beta-Gal-(1 leads to 3)-beta-Gal-(1 leads to 3)-Gal Such oligosaccharide structures have not previously been described in any biological fluid. The origin of these compounds, and the possibility of a specific metabolic defect are discussed.

Chemical Phenomena↗