Chymotrypsin-like elastase family member 3B also known as elastase-3B, protease E, or fecal elastase is an enzyme that in humans is encoded by the CELA3Bgene.[5][6][7]
Clinical literature that describes human elastase 1 activity in the pancreas or fecal material is actually referring to chymotrypsin-like elastase family member 3B (i.e. the enzyme / protein this article focuses on).[8]
Elastases form a subfamily of serine proteases that hydrolyze many proteins in addition to elastin. Humans have six elastase genes which encode the structurally similar proteins elastase 1, 2, 2A, 2B, 3A, and 3B. Unlike other elastases, elastase 3B has little elastolytic activity. Like most of the human elastases, elastase 3B is secreted from the pancreas as a zymogen and, like other serine proteases such as trypsin, chymotrypsin and kallikrein, it has a digestive function in the intestine. Elastase 3B preferentially cleaves proteins after alanine residues. Elastase 3B may also function in the intestinal transport and metabolism of cholesterol. Both elastase 3A and elastase 3B have been referred to as protease E and as elastase 1, and excretion of this protein in fecal material is frequently used as a measure of pancreatic function in clinical assays.[7]
Fecal elastase is a medical test that measures how well the pancreas is functioning.
The fecal elastase test measures the concentration of the elastase-3B enzyme found in fecal matter with an enzyme-linked immunosorbent assay (ELISA). Results of this test can give a good indication of exocrine pancreatic status, and the test is less invasive and expensive than the current "gold standard", secretin-cholecystokinin test.[9] Levels of fecal elastase lower than 200 μg / g of stool indicate an exocrine insufficiency. Correlations between low levels and chronic pancreatitis[10] and cancer[citation needed] have been reported.
^Molinari I., et al. (September 2004). "Fecal chymotrypsin and elastase-1 determination on one single stool collected at random: diagnostic value for exocrine pancreatic status". Clin Biochem. 37 (9): 758–763. doi:10.1016/j.clinbiochem.2004.03.010. PMID15329313.
^Fecal Elastase 1 ELISA For Exocrine Pancreatic Insufficiency: Comparison With ERCP-Morphology And Fecal Fat Excretion [1]Archived 2007-09-27 at the Wayback Machine
Avilés FX, Pascual R, Salva M, et al. (1989). "Generation of a subunit III-like protein by autolysis of human and porcine proproteinase e in a binary complex with procarboxypeptidase A.". Biochem. Biophys. Res. Commun. 163 (3): 1191–6. doi:10.1016/0006-291X(89)91104-2. PMID2675835.
Wendorf P, Geyer R, Sziegoleit A, Linder D (1989). "Localization and characterization of the glycosylation site of human pancreatic elastase 1". FEBS Lett. 249 (2): 275–8. doi:10.1016/0014-5793(89)80640-4. PMID2737288. S2CID8342954.
Guy-Crotte O, Barthe C, Basso D, et al. (1988). "Characterization of two glycoproteins of human pancreatic juice: P35, a truncated protease E and P19, precursor of protein X.". Biochem. Biophys. Res. Commun. 156 (1): 318–22. doi:10.1016/S0006-291X(88)80842-8. PMID3178837.
Shen WF, Fletcher TS, Largman C (1987). "Primary structure of human pancreatic protease E determined by sequence analysis of the cloned mRNA". Biochemistry. 26 (12): 3447–52. doi:10.1021/bi00386a030. PMID3477287.
