Kitajima K, Inoue S, Kitazume S, Inoue Y
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
Anal Biochem. 1992 Sep;205(2):244-50. doi: 10.1016/0003-2697(92)90430-f.
In 1986 we reported the natural occurrence of deaminated neuraminic acid (2-keto-3-deoxy-D-glycero-D-galactonononic acid, KDN) in fish egg glycoprotein. Subsequently, we have shown that many types of sialic acid as well as KDN occur in polymeric chains, poly(oligo)-Sia and poly(oligo)KDN in nature. In this study we demonstrate that the conventional colorimetric and gas-liquid chromatographic methods used in the analysis of sialic acid can be applied to analysis of these new nonulosonate and poly(oligo)nonulosonates. We report that the thiobarbituric acid reaction can be used to analyze both free and bound KDN, but gives lower extinction values when applied to poly(oligo)KDN without prior hydrolysis. Further, the published hydrolytic and/or methanolytic procedures are suitable to release the terminal sialic acid residues, but are not appropriate for quantitative release of the nonulosonic acids from poly(oligo)nonulosonates. A new gas-liquid chromatographic procedure for the identification-quantitation of nonulosonates in poly(oligo)meric forms is described.
1986年，我们报道了鱼卵糖蛋白中天然存在脱氨神经氨酸（2-酮-3-脱氧-D-甘油-D-半乳糖壬糖酸，KDN）。随后，我们发现自然界中许多类型的唾液酸以及KDN都存在于聚合物链、聚（寡聚）唾液酸和聚（寡聚）KDN中。在本研究中，我们证明了用于分析唾液酸的传统比色法和气液色谱法可应用于这些新的九碳糖酸和聚（寡聚）九碳糖酸的分析。我们报告硫代巴比妥酸反应可用于分析游离和结合的KDN，但在未经预先水解就应用于聚（寡聚）KDN时，其吸光度值较低。此外，已发表的水解和/或甲醇解方法适用于释放末端唾液酸残基，但不适用于从聚（寡聚）九碳糖酸中定量释放九碳糖酸。本文描述了一种用于鉴定和定量聚（寡聚）形式的九碳糖酸的新气液色谱方法。
