title: Cellular metabolism of unnatural sialic acid precursors.
abstract: Carbohydrates, in addition to their metabolic functions, serve important roles as receptors, ligands, and structural molecules for diverse biological processes. Insight into carbohydrate biology and mechanisms has been aided by metabolic oligosaccharide engineering (MOE). In MOE, unnatural carbohydrate analogs with novel functional groups are incorporated into cellular glycoconjugates and used to probe biological systems. While MOE has expanded knowledge of carbohydrate biology, limited metabolism of unnatural carbohydrate analogs restricts its use. Here we assess metabolism of SiaDAz, a diazirine-modified analog of sialic acid, and its cell-permeable precursor, Ac4ManNDAz. We show that the efficiency of Ac4ManNDAz and SiaDAz metabolism depends on cell type. Our results indicate that different cell lines can have different metabolic roadblocks in the synthesis of cell surface SiaDAz. These findings point to roles for promiscuous intracellular esterases, kinases, and phosphatases during unnatural sugar metabolism and provide guidance for ways to improve MOE.
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
authors.forename: Nam D
authors.initials: ND
authors.lastname: Pham
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Fermaintt
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Rodriguez
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
authors.forename: Janet E
authors.initials: JE
authors.lastname: McCombs
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Nischan
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. jennifer.kohler@utsouthwestern.edu.
authors.forename: Jennifer J
authors.identifier: http://orcid.org/0000-0001-5373-3329
authors.initials: JJ
authors.lastname: Kohler
mesh_terms: D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000737:chemistry; D002460:Cell Line; D003978:Diazomethane / Q000737:chemistry; D004950:Esterases / Q000737:chemistry / Q000378:metabolism; D005434:Flow Cytometry; D006001:Glycoconjugates / Q000737:chemistry / Q000378:metabolism*; D006595:Hexosamines / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D060847:Metabolic Engineering; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000378:metabolism*; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism
chemical_list: D002241:Carbohydrates; D006001:Glycoconjugates; D006595:Hexosamines; D009844:Oligosaccharides; D003978:Diazomethane; D004950:Esterases; D019158:N-Acetylneuraminic Acid
keywords: Diazirine; Esterase; Metabolic engineering; Photocrosslinking; Sialic acid