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本文通过500MHz质子核磁共振谱研究了二价钙离子与唾液酸的相互作用。在不同Ca~(2+)浓度测量了唾液酸质子的化学位移变化,观察到H_7和H_8以及H_8和H_(9′)质子之间自旋-自旋耦合常数的变化。对这些Ca~(2+)诱导的变化进行分析后发现,唾液酸糖环第六碳位上的侧链构象发生变化,(OH)_7,(OH)_8和(OH)_9羟基中三个氧原子形成一个适合于Ca~(2+)配位的几何空间。因此,唾液酸分子具有一个高亲和力的Ca~(2+)结合部位,其结合常数约为104.72M~(-1)。
In this paper, 500MHz proton nuclear magnetic resonance spectroscopy of divalent calcium ions and sialic acid interaction. The chemical shifts of sialic acid protons were measured at different concentrations of Ca 2+, and the change of spin-spin coupling constants between H_7 and H_8 and between H_8 and H_ (9) protons was observed. Analysis of these Ca ~ (2 +) - induced changes showed that the side chain conformation changed at the sixth carbon position of sialic acid sugar ring. Three of (OH) _7, (OH) _8 and Oxygen atoms form a suitable geometric space for Ca ~ (2+) coordination. Therefore, the sialic acid molecule has a high-affinity Ca 2+ binding site with a binding constant of about 104.72 M -1.