N-glycan profiling of bovine follicular fluid at key dominant follicle developmental stages

Abstract

Follicular fluid (FF), an important microenvironment for the development of oocytes, contains many proteins that are glycosylated with N-linked glycans. This study aimed i) to present an initial analysis of the N-linked glycan profile of bovine FF using hydrophilic interaction liquid chromatography, anion exchange chromatography, high performance liquid chromatography (HPLC)-based separations and subsequent liquid chromatography-mass spectrometry/mass spectrometry analysis; ii) to determine differences in the N-glycan profile between FF from dominant and subordinate follicles from dairy heifers and lactating dairy cows and iii) to identify alterations in the N-glycan profile of FF during preovulatory follicle development using newly selected, differentiated (preovulatory) and luteinised dominant follicles from dairy heifers and lactating cows. We found that the majority of glycans on bovine FF are based on biantennary hypersialylated structures, where the glycans are sialylated on both the galactose and N-acetylglucosamine terminal sugars. A comparison of FF N-glycans from cows and heifers indicated higher levels of nonsialylated glycans with a lower proportion of sialylated glycans in cows than in heifers. Overall, as the follicle develops from Selection, Differentiation and Luteinisation in both cows and heifers, there is an overall decrease in sialylated structures on FF N-glycans.

Hydrophilic interaction chromatography for the analysis of biopharmaceutical drugs and therapeutic peptides: A review based on the separation characteristics of the hydrophilic interaction chromatography phases

“…Isomers of triantennary sialylated N ‐glycans were separated with worse Rs on ZIC‐HILIC in shorter (15 min) gradient time . On TSKgel Amide‐80, several isomers based on connectivity were separated, although some of them co‐eluted .…”

“…Copyright 2014 with permission of American Chemical Society. based on connectivity were separated, although some of them co-eluted [230].…”