Lipid Intermediates in the Synthesis of the Inner Core of Yeast Mannan

Parodi, Armando J.

doi:10.1111/j.1432-1033.1978.tb12090.x

Cited by 32 publications

(11 citation statements)

References 28 publications

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“…Incorporation of mannose from GDP-mannose into alkali-stable positions under conditions where formation of DolP-Man is inhibited, decreases by only 63 ';(< suggesting that some of the mannose residues in this part of the mannoprotein come directly from GDP-mannose. A similar observation has been made with amphomycin [18] in the pig aorta system, where mannose was still [16,20]. The remaining capacity of the system in vitro (Table 3) to transfer mannose from GDP-mannose to alkali-stable positions in presence of diumycin probably comprise all those glycosyl transfer reactions where DolPP derivatives with partially completed oligosaccharides serve as donors.…”

Section: Effect Of D I U J I~~ ( I N On Mannocyl Trunsfir From Gdp-nisupporting

confidence: 77%

Inhibition of Lipid‐Linked Mannose and Mannoprotein Synthesis in Yeast by Diumycin in vitro

Babczinski

1980

European Journal of Biochemistry

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Diumycin, a phosphoglycolipid antibiotic, inhibits different mannosyl transfer reactions in yeast. Using membrane preparations, the drug effectively inhibited the formation of dolichyl phosphate mannose (DolP-Man); 50 % inhibition was observed at approximately 10 pg/ml. To a lesser extent also mannosyl transfer from DolP-Man to protein decreased in presence of diumycin. Both mannosyl transfer to protein-serine/threonine acceptor sites as well as into positions within the asparagine-linked polymannose part of the yeast mannoprotein are inhibited to about 60 under conditions where DolP-Man formation is blocked. DolP-Man synthesis as well as mannosyl transfer from DolP-Man to protein are also inhibited by diumycin using solubilized enzymes and exogenous acceptor substrates.Glycosyltransfer reactions from GDP-mannose either to protein-serine/threonine-linked mannose (formation of short manno-oligosaccharides) or to dolichyl-diphosphate-linked chitobiose (formation of lipid-linked trisaccharide) are not inhibited by diumycin under conditions where DolP-Man synthesis is blocked by the antibiotic.The inhibitory action of diumycin on DolP-Man formation does not seem to be competitive with respect to dolichyl phosphate, since it cannot be overcome by higher concentrations of dolichyl phosphate.Inhibitors of the lipid-linked saccharide pathway are useful tools for the elucidation of the mechanisms both of the distinct partial reactions involved and the regulation of the dolichol-mediated reaction sequence. Several antibiotics and other drugs inhibiting the dolichol-mediated pathway have been described (reviewed in [l, 2] (Reaction 1, see below). In the present investigations this drug was used to study its effects on different mannosylation reactions in yeast in vitro.In Succhuromyces cerevisiue several cell-walllocated biopolymers have been demonstrated to be mannoproteins, which are glycosylated by membrane-bound enzymes. Two kinds of protein-carboAhhreviation.~. DolP, dolichyl monophosphate; DolPP, dolichyl diphosphate; Man, mannose; GlcNAc, N-acetylglucosamine; (GlcNAc)2, chitobiose; GDP-Man, guanosine diphosphate mannose.hydrate linkages are present in the cell-wall mannoproteins : an N-glycosidic one between asparagine and a chitobiose-(mannose). carbohydrate chain [6], and an 0-glycosidic one between serine/threonine and short manno-oligosaccharides [7]. Their biosynthesis in the yeast system has been studied intensively [8-111. Yeast membrane preparations catalyze, among others, the following mannosylation reactions :Data are presented to show that diumycin inhibits the formation of DolP-Man (Reaction 1) and to a lesser extent also the transfer of mannose from the lipid intermediate to serine/threonine residues of acceptor protein (Reaction 2), whereas neither the protein mannosylating reactions which are mediated directly -+ (Protein-Ser/Thr)-Man + DolP

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Section: Effect Of D I U J I~~ ( I N On Mannocyl Trunsfir From Gdp-nisupporting

confidence: 77%

Inhibition of Lipid‐Linked Mannose and Mannoprotein Synthesis in Yeast by Diumycin in vitro

Babczinski

1980

European Journal of Biochemistry

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“…The first step in this process is the formation of dolichol pyrophosphate-GlcNAc from dolichol monophosphate and UDP-GlcNAc (152). By a sequence of further transglycosylic reactions, another unit of GlcNAc is added, and the formed dolichol pyrophosphate-N,N'-diacetylchitobiose is further mannosylated by one mannosyl unit attached by a ,-1,3 bond and by one or more mannosyl units mutually linked by a-glycosidic bonds (152,154,194,202,203). There is preliminary evidence (67; W. Tanner, personal communication) to suggest that the subsequent mannosylation of the lipidlinked N,N'-diacetylchitobiose proceeds, at least partly, with involvement of dolichol monophosphate-mannose as the immediate mannosyl donor.…”

Section: Farkasmentioning

confidence: 99%

Biosynthesis of cell walls of fungi.

Farkas¹

1979

Microbiological Reviews

196

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FORMATION OF CELL WALLS .120 General .120 Biosynthesis of Individual Wall Components .121 Chitin .121 Glucans .124 ten on this subject in the last years (e.g., 5, 9, 10, 15, 16, 205). However, some general explanations are necessary to serve as an introduction to the problem of fungal cell walls. Chemical Structure The remarkable properties of fungal walls, such as their mechanical strength, morphological features, and biological activity, are undoubtedly based on their particular chemical composition. Bartnicki-Garcia (15) pointed out that a close correlation exists between taxonomic classification and cell wall composition among fungi. Polysaccharides, which represent about 80 to 117

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“…This overall structure of the mannan-protein complex was also supported by the results from the biosynthetic studies. Lehle and Tanner [27] and Parodi [28] have established the biosynthetic pathway of mannan. They claimed that dolichyl diphosphate N-acetylglucosaminyl N-acetylglucosaminyl mannooligosaccharide is involved in the formation of the inner core and dolichyl phosphate mannose is the precursor of the base labile oligosaccharides.…”

Section: P-elim Ina T Ionmentioning

confidence: 99%

Comparison of the Mannan Structure from the Cell‐Wall Mutant Candida sp. M‐7002 and Its Wild Type

Hamada

Nakajima

Izaki

et al. 1981

European Journal of Biochemistry

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The cell-wall mutant of a hydrocarbon-assimilating yeast, Candida sp. M-7002 and its wild type have shown a significant difference in mannose content. Each mannan was isolated from the mutant and the wild-type cells by fractionation with Cetavlon and copper reagent. Both mannans contain D-mannose, D-glucose and phosphate. The mutant mannan has a relatively high content of protein (18% in weight bases) whereas the wild-type mannan has a low protein content (5.1 %) with a high amount of carbohydrate (> 90%).Structural analyses by enzymatic and chemical methods showed that both mannans had an mannosidic (a1 -6)-linked back bone substituted at 0 -2 by side chains of varying length. The side chains of the mutant mannan were shown to consist of single mannose units and disaccharide units whose linkages were predominantly M I -2, while the wild-type mannan had two additional side chains of disaccharides. These additional side chains had a1 -3 linkages which were scarcely found in the mutant mannan. P-Elimination reaction demonstrated that the mannans also contain mannosyl oligosaccharides linked to protein through 0-glycosidic linkage.The chemical properties of the mannan of the Candida mutant indicates that the mutation might occur not only in the side chain structure but also in the ( r l -6)-linked mannan back bone.Mannan or mannoprotein is one of the major components of yeast cell walls. Although not completely elucidated as yet, the mannan is thought to have important physiological functions. Besides physical protection of the wall, it may serve to hold enzymes such as invertase and acid phosphatase to the cell wall [I] and may contribute to cell-cell recognition [2]. The structure of the mannan has long been studied by many investigators [3 - In this paper, we describe the comparision of the chemical properties of the mannans from the ccll-b all mutant C'ant/itl(i sp. M-7002 and its wild type. MATERIALS A N D METHODS MaterialsCell-wall mutant, Candida sp. M-7002 and its mother strain were obtained from D r Joji Ono of Central Research Laboratory (Morinaga Milk Co. Ltd.; Tokyo) and were grown with shaking at 30°C in a medium containing 10 g of yeast extract, 2 0 g of peptone and 2 0 g of glucose/l of water. The cells were harvested by centrifugation, washed with water and dried with acetone. Cell-wall mannans were prepared by two precipitation procedures. One was similar to that outlined by Jones and Stoodley [13] using Fehling's solution and the other as described by Lloyd [I41 using Cetavlon (cetyltriinethylammonium bromide). Bio-Gel P-2 (200 -400 mesh) was obtained from Bio-Rad. DEAE-cellulose was obtained from Brown and Sepharose 6B from Pharmacia. a-Glucosidase from yeast, protease from Streptomyces griceus and alkaline phosphatase from calf intestine were purchased from Sigma. General MethodsCarbohydrate was determined by the phenolsulfuric acid method of Dubois et at. [15] and reducing sugars by the method of Somogyi [16]. Protein was determined according to Lowry [I71 and by measuring the absorbance at 28...

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Lipid Intermediates in the Synthesis of the Inner Core of Yeast Mannan

Cited by 32 publications

References 28 publications

Inhibition of Lipid‐Linked Mannose and Mannoprotein Synthesis in Yeast by Diumycin in vitro

Inhibition of Lipid‐Linked Mannose and Mannoprotein Synthesis in Yeast by Diumycin in vitro

Biosynthesis of cell walls of fungi.

Comparison of the Mannan Structure from the Cell‐Wall Mutant Candida sp. M‐7002 and Its Wild Type

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