title: Chemical remodeling of cell-surface sialic acids through a palladium-triggered bioorthogonal elimination reaction.
abstract: We herein report a chemical decaging strategy for the in situ generation of neuramic acid (Neu), a unique type of sialic acid, on live cells by the use of a palladium-mediated bioorthogonal elimination reaction. Palladium nanoparticles (Pd NPs) were found to be a highly efficient and biocompatible depropargylation catalyst for the direct conversion of metabolically incorporated N-(propargyloxycarbonyl)neuramic acid (Neu5Proc) into Neu on cell-surface glycans. This conversion chemically mimics the enzymatic de-N-acetylation of N-acetylneuramic acid (Neu5Ac), a proposed mechanism for the natural occurrence of Neu on cell-surface glycans. The bioorthogonal elimination was also exploited for the manipulation of cell-surface charge by unmasking the free amine at C5 to neutralize the negatively charged carboxyl group at C1 of sialic acids.
authors.affiliation: Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Peking-Tsinghua Center for Life Sciences, Beijing (China); Academy for Advanced Interdisciplinary Studies, Peking University (China).
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Cheng
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Zhaoyue
authors.initials: Z
authors.lastname: Zhang
authors.forename: Weiyao
authors.initials: W
authors.lastname: Hong
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
authors.forename: Peng R
authors.initials: PR
authors.lastname: Chen
mesh_terms: D000107:Acetylation; D000818:Animals; D016466:CHO Cells; D002384:Catalysis; D002470:Cell Survival / Q000187:drug effects; D057930:Click Chemistry; D003412:Cricetulus; D005434:Flow Cytometry; D006801:Humans; D019169:Jurkat Cells; D053768:Metal Nanoparticles / Q000737:chemistry*; D009438:Neuraminic Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D010165:Palladium / Q000737:chemistry* / Q000494:pharmacology*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D012794:Sialic Acids / Q000096:biosynthesis / Q000138:chemical synthesis* / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D009438:Neuraminic Acids; D011134:Polysaccharides; D012794:Sialic Acids; D010165:Palladium
keywords: bioorthogonal elimination; cell surfaces; metabolic oligosaccharide engineering; palladium; sialic acids