Nucleotide sugar purification using membranes

摘要

The invention provides methods of removing contaminants from a mixture of a desired product and contaminants by pH adjustments and molecular weight cut-offs. The contaminants include phosphate groups, magnesium sulfate, sodium pyruvate and tetrasodium pyrophosphate groups. The desired product includes nucleotide sugars, glycolipids, LnNT, sialyl lactose, and salts.

主权项

1. A method of removing essentially all of a contaminant from a mixture comprising the contaminant and a nucleotide sugar comprising a branched PEG structure, the method comprising:
contacting the mixture with a first membrane for a length of time sufficient to allow essentially all of the contaminant to pass through the first membrane wherein the mixture has a pH such that the first membrane and the nucleotide sugar comprising a branched PEG structure have a net charge of the same sign and the contaminant has a net charge which is neutral or a sign which is opposite of the sign of the net charge for the first membrane; and the first membrane has a molecular weight cut-off that is less than the molecular weight of the nucleotide sugar comprising a branched PEG structure; and wherein the branched PEG structure has a formula of: wherein m and n are integers independently selected to provide a PEG moiety having a molecular weight of 2 kDa, 5 kDa, 10 kDa, 20 kDa, 30 kDa, or 40 kDa; thereby removing essentially all of the contaminant from the mixture.