Glycoside hydrolases, also referred to as glycosidases or glycosyl hydrolases., are enzymes that catalyze the hydrolysis of the glycosidic linkage of glycosides, leading to the formation of a sugar hemiacetal or hemiketal and the corresponding free aglycon.
This widespread group of enzymes (EC:3.2.1.) hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of 85 different families [PMID: 7624375 , PMID: 8535779 ]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site.
Caution: Because of the modular nature of CAZymes, these activities may not be directly associated with the family but simply borne by adjacent modules.