INTESTINAL BRUSH-BORDER GLYCOHYDROLASES - STRUCTURE, FUNCTION, AND DEVELOPMENT

The hydrolytic enzymes of the intestinal brush border membrane are ess ential for the degradation of nutrients to absorbable units. Particula rly, the brush border glycohydrolases are responsible for the degradat ion of di- and oligosaccharides into monosaccharides, and are thus cru cial for the energy-intake of humans and other mammals. This review wi ll critically discuss all that is known in the literature about intest inal brush border glycohydrolases. First, we will assess the importanc e of these enzymes in degradation of dietary carbohydrates. Then, we w ill closely examine the relevant features of the intestinal epithelium which harbors these glycohydrolases. Each of the glycohydrolytic brus h border enzymes will be reviewed with respect to structure, biosynthe sis, substrate specificity, hydrolytic mechanism, gene regulation and developmental expression. Finally, intestinal disorders will be discus sed that affect the expression of the brush border glycohydrolases. Th e clinical consequences of these enzyme deficiency disorders will be d iscussed. Concomitantly, these disorders may provide us with important details regarding the functions and gene expression of these enzymes under specific (pathogenic) circumstances.