Caerulein
[CAS# 17650-98-5]

Identification

• Classification: Biochemical >> Peptide
• Name: Caerulein
• Synonyms: (3S)-3-[[(2S)-5-amino-5-oxo-2-[[(2S)-5-oxopyrrolidine-2-carbonyl]amino]pentanoyl]amino]-4-[[(2S)-1-[[(2S,3R)-1-[[2-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-amino-1-oxo-3-phenylpropan-2-yl]amino]-3-carboxy-1-oxopropan-2-yl]amino]-4-methylsulfanyl-1-oxobutan-2-yl]amino]-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-1-oxo-3-(4-sulfooxyphenyl)propan-2-yl]amino]-4-oxobutanoic acid
• Protein Sequence: XQDXTGWMDF
• Molecular Formula: C₅₈H₇₃N₁₃O₂₁S₂
• Molecular Weight: 1352.40
• CAS Registry Number: 17650-98-5
• SMILES: C[C@H]([C@@H](C(=O)NCC(=O)N[C@@H](CC1=CNC2=CC=CC=C21)C(=O)N[C@@H](CCSC)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC3=CC=CC=C3)C(=O)N)NC(=O)[C@H](CC4=CC=C(C=C4)OS(=O)(=O)O)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@@H]5CCC(=O)N5)O

Discovory and Applicatios

Caerulein is a decapeptide originally isolated from the skin secretions of the Australian green tree frog. It was discovered as a bioactive compound with strong gastrointestinal effects, particularly stimulating smooth muscle contraction and secretion in the digestive system. Structurally, caerulein is closely related to the mammalian hormone cholecystokinin, sharing similarities in its amino acid sequence and biological activity.

The initial discovery of caerulein arose from studies aimed at identifying natural compounds influencing digestive function. Researchers found that caerulein induced potent contraction of the gallbladder and stimulated pancreatic secretion, highlighting its potential as a tool for studying digestive physiology. Due to its close relation to cholecystokinin, caerulein was instrumental in understanding hormone-regulated digestion and the signaling pathways involved in gastrointestinal motility and enzyme secretion.

In clinical and experimental settings, caerulein has been used to model pancreatitis in animals by inducing pancreatic hyperstimulation and inflammation. This application has allowed researchers to study the pathophysiology of acute pancreatitis and to evaluate potential therapeutic agents. Its ability to mimic the physiological actions of cholecystokinin also makes it valuable in research focused on digestive enzymes, gallbladder function, and satiety signaling.

Caerulein’s synthetic analogs have been developed to enhance stability and receptor specificity, facilitating its use in various biomedical research applications. It remains an important biochemical tool in experimental pharmacology, enabling detailed analysis of cholecystokinin receptor function and related digestive processes.

Beyond research, caerulein's pharmacological profile has sparked interest in its potential therapeutic uses, particularly concerning disorders involving impaired gastrointestinal motility or pancreatic function. However, its clinical use is primarily limited to research and experimental models rather than direct therapeutic application.

Overall, the discovery of caerulein provided critical insights into gastrointestinal hormone function and facilitated advances in digestive disease research. Its application as a research agent continues to support the understanding of digestive physiology and pathology.

References

1972. The Influence of Caerulein-Like Peptides on Gastric Secretion and Peptic Ulcer Formation in Cats. Digestion, 6(4-5).
DOI: 10.1159/000197169

1979. Amino Acid Transport in the Exocrine Pancreas. IV. Do Glucagon or Insulin Mediate the in Vivo Effect of Caerulein on Amino Acid Transport and Incorporation? Hormone and Metabolic Research, 11(5).
DOI: 10.1055/s-0028-1092737

1987. Rapid increases in inositol 1,4,5-trisphosphate, inositol 1,3,4,5-tetrakisphosphate and cytosolic free Ca2+ in agonist-stimulated pancreatic acini of the rat. Effect of carbachol, caerulein and secretin. The Biochemical Journal, 242(1).
DOI: 10.1042/bj2420289