Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M2S), Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, PB 2457, B-3001 Leuven, Belgium.
Carbohydr Res. 2010 Dec 10;345(18):2583-95. doi: 10.1016/j.carres.2010.10.002. Epub 2010 Nov 1.
Pectin methylesterase (PME) catalyses the demethoxylation of pectin, a major plant cell wall polysaccharide. Through modification of the number and distribution of methyl-esters on the pectin backbone, PME affects the susceptibility of pectin towards subsequent (non-) enzymatic conversion reactions (e.g., pectin depolymerisation) and gel formation, and, hence, its functionality in both plant cell wall and pectin-containing food products. The enzyme plays a key role in vegetative and reproductive plant development in addition to plant-pathogen interactions. In addition, PME action can impact favourably or deleteriously on the structural quality of plant-derived food products. Consequently, PME and also the proteinaceous PME inhibitor (PMEI) found in several plant species and specifically inhibiting plant PMEs are highly relevant for plant biologists as well as for food technologists and are intensively studied in both fields. This review paper provides a structured, comprehensive overview of the knowledge accumulated over the years with regard to PME and PMEI. Attention is paid to both well-established and novel data concerning (i) their occurrence, polymorphism and physicochemical properties, (ii) primary and three-dimensional protein structures, (iii) catalytic and inhibitory activities, (iv) physiological roles in vivo and (v) relevance of (endogenous and exogenous) enzyme and inhibitor in the (food) industry. Remaining research challenges are indicated.
果胶甲酯酶（PME）催化果胶的脱甲氧基作用，果胶是一种主要的植物细胞壁多糖。通过改变果胶主链上甲酯的数量和分布，PME 影响果胶对后续（非）酶转化反应（例如果胶解聚）和凝胶形成的敏感性，从而影响其在植物细胞壁和含果胶食品中的功能。该酶除了在植物-病原体相互作用中发挥作用外，还在植物营养和生殖发育中发挥关键作用。此外，PME 的作用可能对植物源性食品的结构质量产生有利或不利的影响。因此，PME 以及在几种植物物种中发现的蛋白性质胶甲酯酶抑制剂（PMEI），特别是抑制植物 PME 的 PMEI，对植物生物学家以及食品技术人员都具有高度相关性，并在这两个领域都得到了深入研究。本文综述了多年来在 PME 和 PMEI 方面积累的知识，重点介绍了有关它们的存在、多态性和物理化学性质、一级和三维蛋白质结构、催化和抑制活性、体内生理作用以及（内源性和外源性）酶和抑制剂在（食品）工业中的相关性的成熟和新颖数据。还指出了剩余的研究挑战。
