Maltase

Maltase, drawn from PDB 1OBB.

Maltase (EC 3.2.1.20) is an enzyme produced by the cells lining the small intestine which specifically breaks down the disaccharide maltose. It comes under the enzyme category carbohydrase (which is a subcategory of hydrolase), and the disaccharide it hydrolyses is maltose.

Maltase is secreted by the surface cells of the villi, which are thin projections on the mucosa. These are found throughout the small intestine, but differ in shape in the duodenum and ileum sections.

The maltase works like any other enzyme, with the substrate (maltose) binding with the active site. When the maltose had bound with the maltase, the former is hydrolysed, that is to say it is split into its component parts, i.e. two molecules of α-glucose. This is done by breaking the glycosidic bond between the 'first' carbon of one glucose, and the 'fourth' carbon of the other (a 1-4 bond).