Sequence, structure and functionality of pectin methylesterases and their use in sustainable carbohydrate bioproducts: A review

Pectin methylesterases (PMEs) are enzymes that play a critical role in modifying pectins, a class of complex polysaccharides in plant cell walls. These enzymes catalyze the removal of methyl ester groups from pectins, resulting in a change in the degree of esterification and consequently, the physicochemical properties of the polymers. PMEs are found in various plant tissues and organs, and their activity is tightly regulated in response to developmental and environmental factors. In addition to the biochemical modification of pectins, PMEs have been implicated in various biological processes, including fruit ripening, defense against pathogens, and cell wall remodelling. This review presents updated information on PMEs, including their sources, sequences and structural diversity, biochemical properties and function in plant development. The article also explores the mechanism of PME action and the factors influencing enzyme activity. In addition, the review highlights the potential applications of PMEs in various industrial sectors related to biomass exploitation, food, and textile industries, with a focus on development of bioproducts based on eco-friendly and efficient industrial processes.