sialic acid | 195153-20-9

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: sialic acid
• 英文别名: (4S,5R,6S,7S,8R)-5-acetamido-4,6,7,8,9-pentahydroxy-2-oxononanoic acid
• CAS: 195153-20-9
• 化学式: C₁₁H₁₉NO₉
• 分子量: 309.273
• InChiKey: KBGAYAKRZNYFFG-HFJFPFSUSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -4.2
• 重原子数：
  21
• 可旋转键数：
  9
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.73
• 拓扑面积：
  185
• 氢给体数：
  7
• 氢受体数：
  9

反应信息

• 作为反应物：
  描述：

  sialic acid 、 n-Butyl 4-O-beta-D-Galactopyranosyl-beta-D-glucopyranoside 在 α-2,3-sialyltransferase 、 cytidine 5′-triphosphate disodium salt 、 CMP-sialic acid synthetase 、 magnesium chloride 、 1,4-二巯基-2,3-丁二醇 、 alkaline phosphatase 作用下， 生成
  参考文献：
  名称：

  Substrate Recognition of the Membrane-Associated Sialidase NEU3 Requires a Hydrophobic Aglycone

  摘要：

  The human neuraminidases (NEU) consist of a family of four isoforms (NEU1-NEU4). Members of this enzyme family are proposed to have important roles in health and disease through regulation of the composition of cellular sialosides. The NEU3 isoform is a membrane-associated enzyme that cleaves glycolipid substrates. However, few reports have examined the substrate specificity of the enzyme for non-natural substrates. We report here a series of 11 synthetic trisaccharides that feature modifications of the aglycone or the Neu5Ac residue of an octyl beta-sialyllactoside. The time course of substrate cleavage by NEU3 was monitored using an electrospray ionization mass spectrometry assay to obtain relative rates (k(rel)). We observed that NEU3 substrate activity was directly dependent upon the hydrophobicity of the aglycone but had no apparent requirement for features of the ceramide headgroup. We also observed that trisaccharides with incorporated azide groups in the Neu5Ac residue at either C9 or the N5-Ac position were substrates, and in the case of the N5-azidoacetyl derivative, the activity was superior to that of GM3. However, the incorporation of larger aryl groups was tolerated only at C9, but not at N5-Ac. We propose a two-site model for enzyme recognition, requiring interaction at both the Neu5Ac residue and the hydrophobic aglycone.

  DOI：

  10.1021/bi200449j

文献信息

• Substrate Recognition of the Membrane-Associated Sialidase NEU3 Requires a Hydrophobic Aglycone
  作者：Mahendra S. Sandbhor、Naoto Soya、Amgad Albohy、R. Blake Zheng、Jonathan Cartmell、David R. Bundle、John S. Klassen、Christopher W. Cairo

  DOI：10.1021/bi200449j

  日期：2011.8.16

  The human neuraminidases (NEU) consist of a family of four isoforms (NEU1-NEU4). Members of this enzyme family are proposed to have important roles in health and disease through regulation of the composition of cellular sialosides. The NEU3 isoform is a membrane-associated enzyme that cleaves glycolipid substrates. However, few reports have examined the substrate specificity of the enzyme for non-natural substrates. We report here a series of 11 synthetic trisaccharides that feature modifications of the aglycone or the Neu5Ac residue of an octyl beta-sialyllactoside. The time course of substrate cleavage by NEU3 was monitored using an electrospray ionization mass spectrometry assay to obtain relative rates (k(rel)). We observed that NEU3 substrate activity was directly dependent upon the hydrophobicity of the aglycone but had no apparent requirement for features of the ceramide headgroup. We also observed that trisaccharides with incorporated azide groups in the Neu5Ac residue at either C9 or the N5-Ac position were substrates, and in the case of the N5-azidoacetyl derivative, the activity was superior to that of GM3. However, the incorporation of larger aryl groups was tolerated only at C9, but not at N5-Ac. We propose a two-site model for enzyme recognition, requiring interaction at both the Neu5Ac residue and the hydrophobic aglycone.