Polypeptide having the capacity to form alpha-1,3 glucosyl unit branchings on an acceptor

Method for producing acceptors connected to glucosyl units in alpha 1,3 comprising a rate of connections of such glucosyl units in alpha 1,3 between 1 and 50%, said method comprising the steps of:

• (i) mixing in a reaction medium:
• an isolated polypeptide having the ability to specifically form connections of glucosyl units in alpha-1,3 on an acceptor having at least one hydroxyl moiety, said polypeptide having a sequence identity of at least 99% with SEQ ID NO:9, and wherein said polypeptide maintains an aspartic acid 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);
• a substrate of said polypeptide and;
• an acceptor comprising at least one hydroxyl moiety;
• and
• (ii) incubating said mixture obtained in step (i) so as to obtain connection of glucosyl units in alpha-1,3 on said acceptor,
• wherein the rate of connections of such glucosyl units in alpha 1,3 is controlled by varying the ratio between the substrate concentration and the acceptor concentration.