Enterokinase human

General Description

Human Enterokinase is expressed as a linear 1019 amino acid polypeptide precursor glycoprotein. Proteolytic processing of this precursor generates the biologically active form of enterokinase, which consists of two polypeptide chains (heavy chain and light chain) held together by a single disulfide bond, resulting in formation of a biologically active heterodimer. The heavy chain consists of 784 amino acid residues, and the light consists of 235 amino acid residues. The mRNA is present in the proximal small intestine, and the protein is in enterocytes of the duodenum and proximal jejunum. The gene is mapped to human chromosome 21q21.

Biochem/physiol Actions

Proteases (also called proteolytic enzymes, peptidases, or proteinases) are enzymes that hydrolyze the amide bonds within proteins or peptides. Most proteases act in a specific manner, hydrolyzing bonds at or adjacent to specific residues or a specific sequence of residues contained within the substrate protein or peptide. Proteases play an important role in most diseases and biological processes including prenatal and postnatal development, reproduction, signal transduction, the immune response, various autoimmune and degenerative diseases, and cancer. Enterokinase sequentially cleaves carboxyl side of D-D-D-D-K. It is a serine protease which mainly activates trypsinogen.