Substrate specificity of the sialic acid biosynthetic pathway
Autor: | Kevin J. Yarema, Christina L. Jacobs, Carolyn R. Bertozzi, Scarlett Goon, Stephan Hinderlich, Diana H. Chai, Howard C. Hang |
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Jazyk: | angličtina |
Rok vydání: | 2001 |
Předmět: |
Spectrometry
Mass Electrospray Ionization Glycan Time Factors Stereochemistry Substituent HL-60 Cells Plasma protein binding Biology Models Biological Biochemistry Mass Spectrometry Substrate Specificity Jurkat Cells chemistry.chemical_compound Cytosol Biosynthesis Humans Phosphorylation Cell Nucleus chemistry.chemical_classification Dose-Response Relationship Drug Glycobiology Life Sciences Hexosamines Mannosamine Ketones Carbon N-Acetylneuraminic Acid Sialic acid Enzyme Models Chemical chemistry biology.protein oligosaccharide biosynthesis metabolic engineering sialic acid HeLa Cells Protein Binding |
Zdroj: | Jacobs, Christina L.; Goon, Scarlett; Yarema, Kevin J.; Hinderlich, Stephan; Hang, Howard C.; Chai, Diana H.; et al.(2001). Substrate specificity of the sialic acid biosynthetic pathway. Lawrence Berkeley National Laboratory. Lawrence Berkeley National Laboratory: Lawrence Berkeley National Laboratory. Retrieved from: http://www.escholarship.org/uc/item/6dx948b2 |
Popis: | Unnatural analogs of sialic acid can be delivered to mammalian cell surfaces through the metabolic transformation of unnatural N-acetylmannosamine (ManNAc) derivatives. In previous studies, mannosamine analogs bearing simple N-acyl groups up to five carbon atoms in length were recognized as substrates by the biosynthetic machinery and transformed into cell-surface sialoglycoconjugates [Keppler, O. T., et al. (2001) Glycobiology 11, 11R-18R]. Such structural alterations to cell surface glycans can be used to probe carbohydrate-dependent phenomena. This report describes our investigation into the extent of tolerance of the pathway toward additional structural alterations of the N-acyl substituent of ManNAc. A panel of analogs with ketone-containing N-acyl groups that varied in the lengthor steric bulk was chemically synthesized and tested for metabolic conversion to cell-surface glycans. We found that extension of the N-acyl chain to six, seven, or eight carbon atoms dramatically reduced utilization by the biosynthetic machinery. Likewise, branching from the linear chain reduced metabolic conversion. Quantitation of metabolic intermediates suggested that cellular metabolism is limited by the phosphorylation of the N-acylmannosamines by ManNAc 6-kinase in the first step of the pathway. This was confirmed by enzymatic assay of the partially purified enzyme with unnatural substrates. Identification of ManNAc 6-kinase as a bottleneck for unnatural sialic acid biosynthesis provides a target for expanding the metabolic promiscuity of mammalian cells. |
Databáze: | OpenAIRE |
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