Table 1.

Structure and content of N-glycans in the native and desialylated apo-transferrin, Tf+S and Tf-S, respectively, as determined by UPLC-MS. The N-glycan composition was determined by MS and the percent content of individual structures was calculated from the integrals of corresponding UPLC fluorescence signals [24]. The dominant fractions with a content ≥5% are printed in bold and make up approximately 90% of the total protein. The IS value corresponds to the proposed index of sialylation defined in Eq. (1).