Pancreatic elastase is a form of elastase

Elastase

In molecular biology, elastase is an enzyme from the class of proteases that break down proteins.- Forms and classification:There exist eight human genes for elastase:Bacterial forms: Organisms such as P...

 that is formed in the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

. Elastases form a subfamily of serine proteases that hydrolyze many proteins in addition to elastin.

The first isozyme, pancreatic elastase 1 was initially thought to be expressed in the pancreas. However it was later discovered that it was the only chymotrypsin

Chymotrypsin

Chymotrypsin is a digestive enzyme that can perform proteolysis. Chymotrypsin preferentially cleaves peptide amide bonds where the carboxyl side of the amide bond is a tyrosine, tryptophan, or phenylalanine. These amino acids contain an aromatic ring in their sidechain that fits into a...

-like elastase that was not expressed in the pancreas. Hence this protein has been renamed elastase 1 (ELA1) or chymotrypsin-like elastase family, member 1 (CELA1

CELA1

Chymotrypsin-like elastase family member 1 also known as elastase-1 is an enzyme that in humans is encoded by the CELA1 gene....

). For a period of time, it was thought that that ELA1 / CELA1 was not transcribed

Transcription (genetics)

Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

 into a protein. However it was later discovered that it was expressed in skin keratinocyte

Keratinocyte

Keratinocytes are the predominant cell type in the epidermis, the outermost layer of the human skin, constituting 95% of the cells found there. Those keratinocytes found in the basal layer of the skin are sometimes referred to as "basal cells" or "basal keratinocytes"...

s.

Clinical literature that describes human elastase 1 activity in the pancreas or fecal material is actually referring to chymotrypsin-like elastase family, member 3B (CELA3B

CELA3B

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 CELA3B gene....

).

Isozymes

Humans have five chymotrypsin-like elastase genes which encode the structurally similar proteins:

Family	Gene symbol		Protein name		EC number
	Approved	Previous	Approved	Previous
chymotrypsin- like	CELA1 CELA1 Chymotrypsin-like elastase family member 1 also known as elastase-1 is an enzyme that in humans is encoded by the CELA1 gene....	ELA1	chymotrypsin-like elastase family, member 1	elastase 1, pancreatic
	CELA2A	ELA2A	chymotrypsin-like elastase family, member 2A	elastase 2A, pancreatic
	CELA2B CELA2B Chymotrypsin-like elastase family member 2B is and enzyme that in humans is encoded by the CELA2B gene.- Function :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...	ELA2B	chymotrypsin-like elastase family, member 2B	elastase 2B, pancreatic
	CELA3A	ELA3A	chymotrypsin-like elastase family, member 3A	elastase 3A, pancreatic
	CELA3B CELA3B 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 CELA3B gene....	ELA3B	chymotrypsin-like elastase family, member 3B	elastase 3B, pancreatic

Use as diagnostic

The use of Pancreatic Elastase 1 (E1) in Laboratories to Diagnose Exocrine Pancreatic Insufficiency

Human pancreatic elastase 1 (E1) remains undegraded during intestinal transit. Therefore its concentration in feces reflects exocrine pancreatic function. During an inflammation of the pancreas, E1 is released into the bloodstream. Thus the quantification of pancreatic elastase 1 in serum allows diagnosis or exclusion of acute pancreatitis.

Main indications:

• Diagnosis/exclusion of exocrine pancreatic insufficiency caused by e.g. Chronic Pancreatitis, Cystic Fibrosis, Diabetes Mellitus, Cholelithiasis (Gallstones), “Failure to Thrive”, Pancreatic Cancer, Papillary Stenosis
• Follow-up monitoring of patients with mild or moderate pancreatic insufficiency
• Diagnosis/exclusion of pancreatic involvement in association with gastrointestinal symptoms, abdominal pain or osteoporosis, for example.

Method of detection:

• Sandwich ELISA with two monoclonal antibodies highly specific for human pancreatic elastase 1
• The ELISA kit is based on a microtiter plate (96 well format) with 12 breakable single strips x 8 wells suitable for up to 42 samples in duplicate

Reference concentration:
For adults and children after the first month of life

• Values > 200 µg elastase/g stool indicate normal exocrine pancreatic function

Values < 200 µg elastase/g stool indicate exocrine pancreatic insufficiency.