N-Linked Glycan Structures of Human Lactoferrin Produced by Transgenic Rice

Abstract

Human lactoferrin was produced in genetically engineered rice. N-linked glycan structures of recombinant human lactoferrin were determined. The oligosaccharides liberated by hydrazinolysis were labeled with 2-aminopyridine (PA). The PA-labeled glycans were purified by reverse-phase and size-fractionation HPLCs. The structures of these glycans were identified by HPLC, exoglycosidase digestion, and matrix-assisted laser desorption/ionization time-of-flight (MALDI–TOF) mass spectrometry. The glycan structures determined were ManFucXylGlcNAc₂ (3.4%), Man₂FucGlcNAc₂ (2.1%), Man₃FucGlcNAc₂ (2.5%), Man₃FucXylGlcNAc₂ (42.5%), two isomers of Man₂FucXylGlcNAc₂ (39.1%), Man₃XylGlcNAc₂ (6.5%), and Man₂XylGlcNAc₂ (3.9%).