Very high molar mass dextrans

Patent metadata

Field	Value
Publication number	US-2017145120-A1
Application number	US-201515319736-A
Country	US
Kind code	A1
Filing date	Jun 19, 2015
Priority date	Jun 20, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

The subject matter of the invention is dextrans which have between 95% and 99% of α-1,6 glucosidic bonds, a weight-average molar mass M w at least equal to 0.7×10 9 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.

First claim

1 . Dextrans having a weight-average molar mass M w at least equal to 0.7×10 9 g.mol −1 , and a dispersity index D i of between 1.3 and 3, wherein α-1,6 glucosidic bonds in the dextrans comprise (i) between 95% and 99% of glucosidic bonds, (ii) between 97% and 98% of glucosidic bonds, or (iii) between 97.4% and 97.6%, of glucosidic bonds.

2 . The dextrans of claim 1 , having a weight-average molar mass M w at least equal to 1×10 9 g.mol −1 .

3 . A dextransucrase that is selected from: (i) a dextransucrase comprising the amino acid sequence set forth in SEQ ID NO: 1, (ii) a function-preserving dextransucrase variant having at least 80% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (iii) a function-preserving dextransucrase variant having at least 85% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (iv) a function-preserving dextransucrase variant having at least 90% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (v) a function-preserving dextransucrase variant having at least 95% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (vi) a function-preserving dextransucrase variant having at least 98% sequence identity positions 359 to 1038 of the amino acid sequence SEQ ID NO: 1, and (vii) the dextransucrase or function-preserving dextransucrase variant of any one of (i)-(vi) fused to a purification tag.

4 . A process for producing the dextrans of claim 1 , comprising reacting sucrose with a dextransucrase that is selected from: (i) a dextransucrase comprising the amino acid sequence set forth in SEQ ID NO: 1, (ii) a function-preserving dextransucrase variant having at least 80% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (iii) a function-preserving dextransucrase variant having at least 85% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (iv) a function-preserving dextransucrase variant having at least 90% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (vi) a function-preserving dextransucrase variant having at least 95% sequence identity with positions 359 to 1038 of the amino acid sequence set forth in SEQ ID NO: 1, (vi) a function-preserving dextransucrase variant having at least 98% sequence identity positions 359 to 1038 of the amino acid sequence SEQ ID NO: 1, and (vii) the dextransucrase or function-preserving dextransucrase variant of any one of (i)-(vi) fused to a purification tag.

5 . The process of claim 4 , wherein the step of reacting is carried out (i) at a temperature of between 20° C. and 40° C., (ii) at a temperature of between 25° C. and 35° C., or (iii) at a temperature of between 30° C. and 33° C.

6 . The process of claim 4 , wherein (i) the sucrose is present at a concentration that is between approximately 50 and 200 g.l −1 , or (ii) the sucrose is present at a concentration that is between approximately 50 and 150 g.l −1 .

7 . The process of claim 4 , wherein (i) pH during the step of reacting is between approximately 5 and 6.5, (ii) pH during the step of reacting is between 5 and 6, or (iii) pH during the step of reacting is between 5 and 5.8.

8 . A cosmetic or food composition comprising the dextrans of claim 1 and at least one pharmaceutically acceptable or food-grade support.

9 . A method for thickening, gelling and/or texturizing, a composition, comprising introducing into the composition the dextrans of claim 1 , as a thickener, gelling agent and/or texturing agent.

Assignees

• Inst Nat Des Sciences Appliqées De Toulouse
• Agronomique Inst Nat Rech
• Centre Nat Rech Scient
• Univ Bordeaux
• Inst Polytechnique Bordeaux

Inventors

• Vuillemin Marlène
• Claverie Marion
• Moulis Claire
• Remaud-Simeon Magali
• Grimaud Florent
• Monsan Pierre
• Sabate Agnès
• Garnier Catherine
• Dols-Lafargue Marguerite
• Lucas Patrick

Classifications

• A61Q19/00

  Preparations for care of the skin · CPC title

• A61K8/73

  Polysaccharides · CPC title

• C12N9/1051

  Hexosyltransferases (2.4.1) · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title

• C08B37/0009

  alpha-D-Glucans, e.g. polydextrose, alternan, glycogen; (alpha-1,4)(alpha-1,6)-D-Glucans; (alpha-1,3)(alpha-1,4)-D-Glucans, e.g. isolichenan or nigeran; (alpha-1,4)-D-Glucans; (alpha-1,3)-D-Glucans, e.g. pseudonigeran; Derivatives thereof · CPC title