图1. 同型半乳糖醛酸聚糖(HG)多糖与Ca²⁺交联的“鸡蛋盒”模型(改自Micheli,2001; Braccini and Peréz,2001)
高甲基酯化的HG被果胶甲基酯酶(PME)去甲基酯化, 产生带负电荷的羧基。在Ca²⁺存在时, 2条HG链的羧基与Ca²⁺相互作用, 形成“鸡蛋盒”结构。

Figure 1. An “egg-box” model of homogalacturonan (HG) polysaccharide and Ca ²⁺ cross-linking (modified from Micheli, 2001; Braccini and Peréz,2001)
Hypermethylated HG is de-methylated by pectin methylesterase (PME) to produce negatively charged carboxyl groups. In the presence of Ca²⁺, the carboxyl groups of the two HG chains interact with Ca²⁺ to form an “egg box” structure.