Comparative Study of Cation-Exchange Resins for High-Efficiency Preparation of Bovine Lactoferrin and its <i>N</i> -glycomic Analysis by HILIC-MS/MS

Bovine lactoferrin (bLf) is an essential additive in infant formula, with its bioactivity closely related to <i>N</i>-glycosylation. Currently, the production cost of lactoferrin remains high. This study compared eight ion-exchange resins and identified DoWex and 732 as optimal for bLf purification. Yields reached 4.46% for DoWex and 5.25% for 732, with purities exceeding 85% for both resins. Isomer-specific <i>N</i>-glycan analysis using HILIC-MS/MS revealed 58 distinct <i>N</i>-glycans in mature bLf, including 28 neutral and 30 acidic glycans, with the acidic <i>N</i>-glycans predominantly modified by α2,6-linked Neu5Ac. The bLf prepared by 732 resin shared >97% of the neutral and >93% of the acidic glycans with that of DoWex. Notably, the price of 732 resin is only one-18th that of DoWex, representing a significant reduction in production costs and making it promising in future large-scale manufacturing. This work facilitates efficient lactoferrin production and provides further studies on the relationships between glycans and their functions.