Wyniki wyszukiwania

1

A recent approach to the study of dolichol monophosphate topology in the rough endoplasmic reticulum

100%

Banerjee D. K.

Acta Biochimica Polonica

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1994

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tom 41

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nr 3

Amphomycin though withdrawn as an antibiotic against the gram-positive bacterial infection, can certainly serve as an excellent tool for determination of the topology of Dol-P in the endoplasmic reticulum membranes, which has been otherwise impossible.

2

Effect of N-glycosylation inhibition on the synthesis and processing of classical swine fever virus glycoproteins

84%

Tyborowska J., Zdunek E., Szewczyk B.

Acta Biochimica Polonica

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2007

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tom 54

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nr 4

813-819

Classical swine fever virus (CSFV) is often used as a surrogate model in molecular studies of the closely related hepatitis C virus. In this report we have examined the effect of the inhibition of glycosylation on the survival and maturation of CSFV. Viral glycoproteins (Erns, E1, E2) form biologically active complexes — homo- and heterodimers, which are indispensable for viral life cycle. Those complexes are highly N-glycosylated. We studied the influence of N-glycosylation on dimer formation using Erns and E2 glycoproteins produced in insect cells after infection with recombinant baculoviruses. The glycoproteins were efficiently synthesized in insect cells, had similar molecular masses and formed dimers like their natural counterparts. Surprisingly, the addition of tunicamycin (an antibiotic which blocks early steps of glycosylation) to insect cell culture blocked not only dimer formation but it also led to an almost complete disappearance of E2 even in monomeric form. Tunicamycin did not exert a similar effect on the synthesis and formation of Erns dimers; the dimers were still formed, which suggests that Erns glycan chains are not necessary for dimer formation. We have also found that very low doses of tunicamycin (much lower than those used for blocking N-glycosylation) drastically reduced CSFV spread in SK6 (swine kidney) cell culture and the virus yield. These facts indicate that N-glycosylation inhibitors structurally similar to tunicamycin may be potential therapeutics for the inhibition of the spread of CSFV and related viruses

3

Analysis of recombinant Duffy protein-linked N-glycans using lectins and glycosidases

84%

Grodecka M., Czerwinski M., Duk M., Lisowska E., Wasniowska K.

Acta Biochimica Polonica

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2010

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tom 57

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nr 1

49-53

Duffy antigen is a glycosylated blood group protein acting as a malarial and chemokine receptor. Using glycosylation mutants we have previously demonstrated, that all three potential glycosylation sites of the Duffy antigen are occupied by N-linked oligosaccharide chains. In this study, wild-type Duffy glycoprotein and three mutants, each containing a single N-glycan, were used to characterize the oligosaccharide chains by lectin blotting and endoglycosidase digestion. The positive reaction of all the recombinant Duffy forms with Datura stramonium and Sambucus nigra lectins showed that each Duffy N-linked glycan contains Galβ1-4GlcNAc units terminated by (α2-6)-linked sialic acid residues, typical of complex oligosaccharides. The reactivity with Aleuria aurantia and Lens culinaris lectins suggested the presence of (α1-6)-linked fucose at the N-glycan chitobiose core. The failure of the Galanthus nivalis and Canavalia ensiformis lectins to bind to any of the Duffy mutants or to the wild-type antigen indicated that none of the three Duffy N-glycosylation sites carries detectable levels of high-mannose oligosaccharide chains. Digestion of Duffy samples with peptide N-glycosidase F and endoglycosidase H confirmed the presence of N-linked complex oligosaccharides. Our results indicate that Duffy antigen N-glycans are mostly core-fucosylated complex type oligosaccharides rich in N-acetyllactosamine and terminated by (α2-6)-linked sialic acid residues.

4

Congenital disorders of glycosylation. Part I. Defects of protein N-glycosylation

84%

Cylwik B., Naklicki M., Chrostek L., Gruszewska E.

Acta Biochimica Polonica

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2013

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tom 60

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nr 2

Glycosylation is the most common chemical process of protein modification and occurs in every living cell. Disturbances of this process may be either congenital or acquired. Congenital disorders of glycosylation (CDG) are a rapidly growing disease family, with about 50 disorders reported since its first clinical description in 1980. Most of the human diseases have been discovered recently. CDG result from defects in the synthesis of the N- and O-glycans moiety of glycoproteins, and in the attachment to the polypeptide chain of proteins. These defects have been found in the activation, presentation, and transport of sugar precursors, in the enzymes responsible for glycosylation, and in proteins that control the traffic of component. There are two main types of protein glycosylation: N-glycosylation and O-glycosylation. Most diseases are due to defects in the N-glycosylation pathway. For the sake of convenience, CDG were divided into 2 types, type I and II. CDG can affect nearly all organs and systems. The considerable variability of clinical features makes it difficult to recognize patients with CDG. Diagnosis can be made on the basis of abnormal glycosylation display. In this paper, an overview of CDG with a new nomenclature limited to the group of protein N-glycosylation disorders, clinical phenotype and diagnostic approach, have been presented. The location, reasons for defects, and the number of cases have been also described. This publication aims to draw attention to the possibility of occurrence of CDG in each multisystem disorder with an unknown origin.

5

Nonsteroidal anti-inflammatory drugs (NSAID) sparing effects of glucosamine hydrochloride through N-glycosylation inhibition; strategy to rescue stomach from NSAID damage

67%

Park S. H., Hong H., Han Y. M., Kangwan N., Kim S. J., Kim E. H., Hahm K. B.

Journal of Physiology and Pharmacology

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2013

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tom 64

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nr 2

6

The participation of ribosome-UDP-GalNAc complex in the initiation of protein glycosylation in vitro

67%

Paszkiewicz-Gadek A., Porowska H., Gindzienski A.

Acta Biochimica Polonica

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2000

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tom 47

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nr 2

The gastric epithelial cells ribosome-UDP-GalNAc complex is a donor of UDP- GalNAc as the substrate for N-acetylgalactosaminyltransferase, which catalyse the transfer of GalNAc residue to the polypeptide, existing on polysomes. It was observed that the deglycosylated porcine mucin and synthetic peptide (PTSSPIST) can be also glycosylated with participation of N-acetylgalactosaminyltransferase and ribosome- UDP-GalNAc complex. The probability of the ribosome-UDP-GalNAc complex as an intermediate in the O-glycosylation is considered.

7

Protein C-mannosylation: facts and questions

67%

Furmanek A., Hofsteenge J.

Acta Biochimica Polonica

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2000

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tom 47

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nr 3

Among the posttranslational modifications of proteins, glycosylation is probably the most abundant one. Two main types of protein glycosylation have been known for several years, namely N-glycosylation and O-glycosylation. Their biochemical properties, structure and biosynthesis, have been described extensively. Their biological functions are also known for a number of proteins, although in many cases the function remains speculative despite continuous efforts. A few years ago, a new type of protein glycosylation was found, which is different from the above-mentioned ones. It was called C-glycosylation, since the sugar is linked to the protein through a carbon-carbon bond. This article reviews the biochemistry of C-glycosylation, the biosynthetic pathway and structural requirements. Possible biological functions of this modification are also discussed.

Ograniczanie wyników

A recent approach to the study of dolichol monophosphate topology in the rough endoplasmic reticulum

Effect of N-glycosylation inhibition on the synthesis and processing of classical swine fever virus glycoproteins

Analysis of recombinant Duffy protein-linked N-glycans using lectins and glycosidases

Congenital disorders of glycosylation. Part I. Defects of protein N-glycosylation

Nonsteroidal anti-inflammatory drugs (NSAID) sparing effects of glucosamine hydrochloride through N-glycosylation inhibition; strategy to rescue stomach from NSAID damage

The participation of ribosome-UDP-GalNAc complex in the initiation of protein glycosylation in vitro

Protein C-mannosylation: facts and questions