Substrates of the Human Neuraminidase and Sialic Acid Esterase Enzymes

  • Author / Creator
    Khanna, Neha
  • Neuraminidase enzymes (NEU) catalyze the cleavage of sialic acid residues from sialylated oligosaccharides, glycoproteins, and glycolipids. The human neuraminidase enzymes (hNEU) are a family of four isoenzymes (NEU1, NEU2, NEU3, and NEU4), which cleave terminal sialic acid groups (exo-sialidase). Members of the hNEU family are proposed play important roles in health and disease by controlling the composition of cellular sialosides. The membrane-associated enzyme, NEU3, is responsible for cleaving glycolipid substrates and plays critical roles in cell signaling. Although gangliosides, such as GM3, are known as substrates for NEU3, there are several uncommon natural analogs of this substrate found in human cells, including Neu5Gc and 9-O-Ac-Neu5Ac derivatives. This thesis presents the synthesis and characterization of a series of GM3 analogs {Neu5Acα(2→3)Galβ(1→4)Glcβ(1→1)cer} with an octyl aglycone and containing either Neu5Ac, Neu5Gc, or 9-O-Ac-Neu5Ac terminal residues. Furthermore, we generated each of these compounds with either an α(2→3)- or α(2→6)-glycosidic linkage. Additionally, to examine the role of the sialic acid esterase (SIAE) enzyme, which is responsible for degredation of 9-O-Ac-Neu5Ac residues, we developed a synthesis of a chloro-acetate analog of the esterase substrate, which will be studied as an inhibitor or label of the SIAE.

  • Subjects / Keywords
  • Graduation date
    Fall 2014
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.