endohydrolase

An endohydrolase is a type of enzyme that catalyzes the hydrolysis of an internal bond within a substrate molecule. This means the enzyme breaks a chemical bond by adding a water molecule, and this breakage occurs somewhere in the middle of the substrate, not at its terminal ends. Endohydrolases are a subclass of hydrolases, which are enzymes that catalyze hydrolysis reactions.

These enzymes are crucial in many biological processes. For instance, digestive enzymes like proteases that break down proteins into smaller peptides and amino acids are often endohydrolases. They cleave peptide bonds within the protein chain. Similarly, nucleases that degrade nucleic acids like DNA and RNA are also endohydrolases, breaking phosphodiester bonds internally. Glycosidases that break down complex carbohydrates can also function as endohydrolases, cleaving glycosidic bonds within polysaccharide chains.

The specificity of an endohydrolase for its substrate and the particular bond it cleaves is determined by its active site, which is a region on the enzyme that binds to the substrate. This precise action allows for controlled breakdown of molecules, which is essential for cellular metabolism, nutrient absorption, and the remodeling of cellular structures. Without endohydrolases, many essential biological processes that rely on the breakdown of large molecules would not be possible.