Abstract: The present invention provides protected tetrasaccharides, their process of preparation and their use in the synthesis of oligosaccharides, in particular fragments of O-antigens from Shigella flexneri, for example of serotype 1a, 1b, 2a, 2b, 3a, X, 4a, 4b, 5a, 5b, 7a or 7b.

Abstract: The present invention provides protected tetrasaccharides, their process of preparation and their use in the synthesis of oligosaccharides, in particular fragments of O-antigens from Shigella flexneri, for example of serotype 1a, 1b, 2a, 2b, 3a, X, 4a, 4b, 5a, 5b, 7a or 7b.

Abstract: The present invention relates to a process for preparing an alkyl polyglucoside by enzymatic catalysis, using sucrose or an analogue thereof as substrate and making it possible to obtain a large diversity of alkyl polyglucosides in terms of size and structure of the glucoside part thereof, making possible the obtaining of an alkyl polyglucoside with a number of glucosyl units that can be adjusted from 2 to 200 glucosyl units. The process also makes it possible to adjust the linear or branched structure of the carbohydrate part of the alkyl polyglucoside obtained, and also the nature of the glycosidic bonds linking the glucose residues within the carbohydrate part.

Abstract: Polypeptides having the ability to specifically form connections of glucosyl units in alpha 1,3 on an acceptor having at least one hydroxyl moiety are presented. The polypeptides include i) the pattern I of sequence SEQ ID NO: 1, ii) the pattern II of sequence SEQ ID NO: 2, iii) the pattern III of sequence SEQ ID NO: 3, and iv) the pattern IV of sequence SEQ ID NO: 4, or derivates from one or several of said patterns, wherein the polypeptide furthermore has an aspartic residue (D) at position 5 of the pattern II (SEQ ID NO: 2), a glutamic acid residue (E) at position 6 of the pattern III (SEQ ID NO: 3) an an aspartic acid residue (D) at position 6 of the pattern IV (SEQ ID NO: 4). Methods for producing acceptors connected to glucosyl units in alpha 1,3 using the polypeptides are also provided.

Abstract: Polypeptides having the ability to specifically form connections of glucosyl units in alpha 1,3 on an acceptor having at least one hydroxyl moiety are presented. The polypeptides include i) the pattern I of sequence SEQ ID NO: 1, ii) the pattern II of sequence SEQ ID NO: 2, iii) the pattern III of sequence SEQ ID NO: 3, and iv) the pattern IV of sequence SEQ ID NO: 4, or derivates from one or several of said patterns, wherein the polypeptide furthermore has an aspartic residue (D) at position 5 of the pattern II (SEQ ID NO: 2), a glutamic acid residue (E) at position 6 of the pattern III (SEQ ID NO: 3) and an aspartic acid residue (D) at position 6 of the pattern IV (SEQ ID NO: 4). Methods for producing acceptors connected to glucosyl units in alpha 1,3 using the polypeptides are also provided.

Abstract: Polypeptides having the ability to specifically form connections of glucosyl units in alpha 1,3 on an acceptor having at least one hydroxyl moiety are presented. The polypeptides include i) the pattern I of sequence SEQ ID NO: 1, ii) the pattern II of sequence SEQ ID NO: 2, iii) the pattern III of sequence SEQ ID NO: 3, and iv) the pattern IV of sequence SEQ ID NO: 4, or derivates from one or several of said patterns, wherein the polypeptide furthermore has an aspartic residue (D) at position 5 of the pattern II (SEQ ID NO: 2), a glutamic acid residue (E) at position 6 of the pattern III (SEQ ID NO: 3) an an aspartic acid residue (D) at position 6 of the pattern IV (SEQ ID NO: 4). Methods for producing acceptors connected to glucosyl units in alpha 1,3 using the polypeptides are also provided.

Abstract: The present invention relates to a method for producing a glycosylated synthon or a monomer. Said method includes at least one step of placing at least one glycan-saccharase in the presence of at least one hydroxylated synthon and at least one saccharose. The invention also relates to a method for producing a glyco(co)polymer, including polymerizing at least two monomers separately obtained from the enzymatic glycosylation method according to the invention, and to a method for producing a glyco(co)polymer, preferably a block glyco(co)polymer, including coupling at least two monomers separately obtained from the enzymatic glycosylation method according to the invention.

Abstract: The present invention provides protected tetrasaccharides, their process of preparation and their use in the synthesis of oligosaccharides, in particular fragments of O-antigens from Shigella flexneri, for example of serotype 1a, 1b, 2a, 2b, 3a, X, 4a, 4b, 5a, 5b, 7a or 7b.

Abstract: The invention relates to: —a protein having dextran-saccharase activity and the sequence SEQ ID NO: 1 for an amino acid sequence; —a protein having dextran-saccharase activity and the sequence SEQ ID NO: 2 for an amino acid sequence; —a complex containing a substrate and a protein with dextran-saccharase activity —a method for synthesizing dextrans; and —dextrans. The invention also relates to a method for synthesizing gluco-oligosaccharides and gluco-conjugates and to the resulting products.

Abstract: The subject matter of the invention is dextrans which have between 95% and 99% of ?-1,6 glucosidic bonds, a weight-average molar mass Mw at least equal to 0.7×109 g.mol?1, and a dispersity index D of between 1.3 and 3. The invention also relates to a dextran saccharase which makes it possible to produce such dextrans, and to a method for producing said dextrans.

Abstract: The present invention relates to a method for producing a glycosylated synthon or a monomer. Said method includes at least one step of placing at least one glycan-saccharase in the presence of at least one hydroxylated synthon and at least one saccharose. The invention also relates to a method for producing a glyco(co)polymer, including polymerizing at least two monomers separately obtained from the enzymatic glycosylation method according to the invention, and to a method for producing a glyco(co)polymer, preferably a block glyco(co)polymer, including coupling at least two monomers separately obtained from the enzymatic glycosylation method according to the invention.

Abstract: The present invention relates to a recombinant process for the production of truncated or mutated dextransucrases while conserving the enzymatic activity or their specificity in the synthesis of the ?-1,6 bonds. The present invention relates to nucleic acid sequences of truncated or mutated dextransucrases, vectors containing the nucleic acid sequences and host cells transformed by sequences encoding truncated or mutated dextransucrases. In another aspect, the invention concerns a method for producing, in a recombinant manner, truncated or mutated dextransucrases which conserve their enzymatic activity or which conserve their specificity in the synthesis of ?-1,6 bonds and can produce, from saccharose, dextrans with high molar mass and modified rheological properties compared with the properties of dextran obtained with the native enzyme and isomalto-oligosaccharides with a controlled molar mass and dextrans.

Abstract: Polypeptides having the ability to specifically form connections of glucosyl units in alpha 1,3 on an acceptor having at least one hydroxyl moiety are presented. The polypeptides include i) the pattern I of sequence SEQ ID NO: 1, ii) the pattern II of sequence SEQ ID NO: 2, iii) the pattern III of sequence SEQ ID NO: 3, and iv) the pattern IV of sequence SEQ ID NO: 4, or derivates from one or several of said patterns, wherein the polypeptide furthermore has an aspartic residue (D) at position 5 of the pattern II (SEQ ID NO: 2), a glutamic acid residue (E) at position 6 of the pattern III (SEQ ID NO: 3) and an aspartic acid residue (D) at position 6 of the pattern IV (SEQ ID NO: 4). Methods for producing acceptors connected to glucosyl units in alpha 1,3 using the polypeptides are also provided.

Abstract: The invention relates to: a protein having dextran-saccharase activity and the sequence SEQ ID NO: 1 for an no acid sequence; a protein having dextran-saccharase activity and the sequence SEQ ID NO: 2 for an amino acid sequence; a complex containing a substrate and a protein with dextran-saccharase activity a method for synthesizing dextrans; and dextrans. The invention also relates to a method for synthesizing gluco-oligosaccharides and gluco-conjugates and to the resulting products.

Abstract: The subject matter of the invention is dextrans which have between 95% and 99% of ?-1,6 glucosidic bonds, a weight-average molar mass Mw at least equal to 0.7×109 g.mol?1, and a dispersity index D of between 1.3 and 3. The invention also relates to a dextran saccharase which makes it possible to produce such dextrans, and to a method for producing said dextrans.

Abstract: The present invention relates to a recombinant process for the production of truncated or mutated dextransucrases while conserving the enzymatic activity or their specificity in the synthesis of the ?-1,6 bonds. The present invention relates to nucleic acid sequences of truncated or mutated dextransucrases, vectors containing the nucleic acid sequences and host cells transformed by sequences encoding truncated or mutated dextransucrases. In another aspect, the invention concerns a method for producing, in a recombinant manner, truncated or mutated dextransucrases which conserve their enzymatic activity or which conserve their specificity in the synthesis of ?-1,6 bonds and can produce, from saccharose, dextrans with high molar mass and modified rheological properties compared with the properties of dextran obtained with the native enzyme and isomalto-oligosaccharides with a controlled molar mass and dextrans.

Abstract: The present invention relates to a recombinant process for the production of truncated or mutated dextransucrases while conserving the enzymatic activity or their specificity in the synthesis of the ?-1,6 bonds. The present invention relates to nucleic acid sequences of truncated or mutated dextransucrases, vectors containing the nucleic acid sequences and host cells transformed by sequences encoding truncated or mutated dextransucrases. In another aspect, the invention concerns a method for producing, in a recombinant manner, truncated or mutated dextransucrases which conserve their enzymatic activity or which conserve their specificity in the synthesis of ?-1,6 bonds and can produce, from saccharose, dextrans with high molar mass and modified rheological properties compared with the properties of dextran obtained with the native enzyme and isomalto-oligosaccharides with a controlled molar mass and dextrans.

Abstract: An isolated polypeptide having the ability to specifically form connections of glucosyl units in alpha 1,3 on an acceptor including at least one hydroxyl moiety. The polypeptide includes i) the pattern I of sequence SEQ ID NO: 1, ii) the pattern II of sequence SEQ ID NO: 2, iii) the pattern II of sequence SEQ ID NO: 3, iv) the pattern IV of sequence SEQ ID NO: 4 or derivates from one or several of said patterns. The polypeptide furthermore has the aspartic residue (D) in position 5 of the pattern II (SEQ ID NO: 2), the glutamic acid residue (E) at position 6 of the pattern III (SEQ ID NO: 3) and the aspartic acid residue (D) in position 6 of the pattern IV (SEQ ID NO: 4); and its uses.

Abstract: The present invention relates to a recombinant process for the production of truncated or mutated dextransucrases while conserving the enzymatic activity or their specificity in the synthesis of the ?-1,6 bonds. The present invention relates to nucleic acid sequences of truncated or mutated dextransucrases, vectors containing the nucleic acid sequences and host cells transformed by sequences encoding truncated or mutated dextransucrases. In another aspect, the invention concerns a method for producing, in a recombinant manner, truncated or mutated dextransucrases which conserve their enzymatic activity or which conserve their specificity in the synthesis of ?-1,6 bonds and can produce, from saccharose, dextrans with high molar mass and modified rheological properties compared with the properties of dextran obtained with the native enzyme and isomalto-oligosaccharides with a controlled molar mass and dextrans.

Abstract: The present invention relates to a recombinant process for the production of truncated or mutated dextransucrases while conserving the enzymatic activity or their specificity in the synthesis of the ?-1,6 bonds. The present invention relates to nucleic acid sequences of truncated or mutated dextransucrases, vectors containing the nucleic acid sequences and host cells transformed by sequences encoding truncated or mutated dextransucrases. In another aspect, the invention concerns a method for producing, in a recombinant manner, truncated or mutated dextransucrases which conserve their enzymatic activity or which conserve their specificity in the synthesis of ?-1,6 bonds and can produce, from saccharose, dextrans with high molar mass and modified rheological properties compared with the properties of dextran obtained with the native enzyme and isomalto-oligosaccharides with a controlled molar mass and dextrans.