glycomics analysis of mammalian heparan sulfates modified by the human extracellular sulfatase hsulf2作者分析哺乳动物乙酰肝素硫酸盐改性的人类细胞外硫酸酯酶hsulf2.pdfVIP

Glycomics Analysis of Mammalian Heparan Sulfates Modified by the Human Extracellular Sulfatase HSulf2 Gregory O. Staples., Xiaofeng Shi., Joseph Zaia* Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts, United States of America Abstract Background: The Sulfs are a family of endosulfatases that selectively modify the 6O-sulfation state of cell-surface heparan sulfate (HS) molecules. Sulfs serve as modulators of cell-signaling events because the changes they induce alter the cell surface co-receptor functions of HS chains. A variety of studies have been aimed at understanding how Sulfs modify HS structure, and many of these studies utilize Sulf knockout cell lines as the source for the HS used in the experiments. However, genetic manipulation of Sulfs has been shown to alter the expression levels of HS biosynthetic enzymes, and in these cases an assessment of the fine structural changes induced solely by Sulf enzymatic activity is not possible. Therefore, the present work aims to extend the understanding of substrate specificities of HSulf2 using in vitro experiments to compare HSulf2 activities on HS from different organ tissues. Methodology/Principal Findings: To further the understanding of Sulf enzymatic activity, we conducted in vitro experiments where a variety of mammalian HS substrates were modified by recombinant human Sulf2 (HSulf2). Subsequent to treatment with HSulf2, the HS samples were exhaustively depolymerized and analyzed using size-exclusion liquid chromatography-mass spectrometry (SEC-LC/MS). We found that HSulf2 activity was highly dependent on the structural features of the HS substrate. Additionally, we characterized, for the first time, the activity of HSulf2 on the non-reducin