Chymotrypsin-like elastase family member 3B, Elastase IIIB, Elastase-3B, Protease E, ELA3B, elastase 3B, pancreatic, inactive variant, catalytically inactive
Chymotrypsin-like elastases (CELAs) are pancreatic serine proteinases, which belong to the peptidase S1 family, a subfamily of serine proteases. The human CELA3B is a member of the elastase family, which consists of six human elastase genes encoding the proteins elastase 1, 2, 2A, 2B, 3A, and 3B, all of which are structurally similar. Typically, elastases hydrolyze many proteins in addition to elastin. However, CELA3B has only little elastolytic activity. CELA3B is secreted by the pancreas and characterized by a digestive function in the intestine, very similar to other serine proteases such as trypsin, chymotrypsin and kallikrein. The amino acid S217 of CELA3B is part of the catalytic triade typical for all serine proteases. By substitution of this amino acid by a different one (S217A), the enzyme is loosing its catalytic activity. In clinical assays, pancreatic function is analyzed by excretion of CELA3B in fecal material.
