Ammonium borane complex

PNGase F, G7 buffer (50mM sodium phosphate buffer, pH 7.5) were from New England Biolabs (Ipswich, MA, USA). Ammonium-borane complex, CH₃I iodomethane, Dimethyl sulfoxide (DMSO), NaOH beads were purchased from Sigma-Aldrich (St. Louis, MO, USA), ethanol was from PHARMCO-AAPER, HPLC grade methanol, Acetonitrile (ACN), Formic Acid, HPLC water were obtained from Fisher Scientific (Fair Lawn, New Jersey, USA).

Synthesized N-glycan standards, HexNAc₄Hex₄Fuc₁ isomers with one core or branch fucose, HexNAc₄Hex₅NeuAc₁ isomers with α2,3 or α2,6 NeuAc linkage, and HexNAc₄Hex₅Fuc₁NeuAc₁ isomers with α2,3 or α2,6 NeuAc linkages were purchased from Chemily Glycoscience (Peachtree Corners, GA). Ribonuclease B (RNase B), bovine fetuin and κ-casein, and human serum were purchased from Sigma-Aldrich (St. Louis, MO). Peptide-NGlycosidase F (PNGase F), G7 buffer (50mM sodium phosphate buffer, pH 7.5), and α2-3 Neuraminidase were acquired from New England Biolabs (Ipswich, MA). Breast cancer cell line MDA-MB-231BR was generously provided by Dr. Paul Lockman (West Virginia University, School of Pharmacy, Morgantown, WV). Brain cancer cell line CRL-1620 and Dulbecco’s modified Eagle’s medium (DMEM) were purchased from American Type Culture Collection (ATCC, Manassas, VA). Ammonium-borane complex, iodomethane, dimethyl sulfoxide (DMSO), and sodium hydroxide (NaOH) beads were purchased from Sigma-Aldrich (St. Louis, MO). Ethanol was obtained from PHARMCO-AAPER (Brookfield, CT). HPLC-grade methanol, acetonitrile (ACN), formic acid (FA), and HPLC water were purchased from Fisher Scientific (Fair Lawn, NJ).