Colipase, abbreviated CLPS, is a protein co-enzyme that counteracts the inhibitory effect of intestinal bile acid on the enzymatic activity of pancreatic lipase. It is secreted by the pancreas in an inactive form, procolipase, which is activated in the intestinal lumen by trypsin.

Intestinal bile acids (which aid lipid digestion by facilitating micelle formation) adhere to the surface of emulsified fat droplets, displacing lipase (which is only active at the water-fat interface) from the droplet surface. Colipase acts as a bridging molecule, binding to both lipase and bile acids, thus anchoring lipase onto the droplet surface, preventing its displacement.[5]

In humans, the colipase protein is encoded by the CLPS gene.[6]

Protein domain

Colipase is also a family of evolutionarily related proteins.

Colipase is a small protein cofactor needed by pancreatic lipase for efficient dietary lipid hydrolysis. Efficient absorption of dietary fats is dependent on the action of pancreatic triglyceride lipase. Colipase binds to the C-terminal, non-catalytic domain of lipase, thereby stabilising an active conformation and considerably increasing the hydrophobicity of its binding site. Structural studies of the complex and of colipase alone have revealed the functionality of its architecture.[7][8]

Colipase is a small protein (12K) with five conserved disulphide bonds. Structural analogies have been recognised between a developmental protein (Dickkopf), the pancreatic lipase C-terminal domain, the N-terminal domains of lipoxygenases and the C-terminal domain of alpha-toxin. These non-catalytic domains in the latter enzymes are important for interaction with membrane. It has not been established if these domains are also involved in eventual protein cofactor binding as is the case for pancreatic lipase.[8]

See also

References

  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000137392Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000024225Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Koeppen, Bruce M.; Stanton, Bruce A.; Swiatecka-Urban, Agnieszka, eds. (2024). Berne & Levy Physiology (8th ed.). Philadelphia, PA: Elsevier. ISBN 978-0-323-84790-2.
  6. ^ Davis RC, Xia YR, Mohandas T, Schotz MC, Lusis AJ (May 1991). "Assignment of the human pancreatic colipase gene to chromosome 6p21.1 to pter". Genomics. 10 (1): 262–5. doi:10.1016/0888-7543(91)90509-D. PMID 2045105.
  7. ^ Lowe ME (1997). "Structure and function of pancreatic lipase and colipase". Annu. Rev. Nutr. 17: 141–158. doi:10.1146/annurev.nutr.17.1.141. PMID 9240923.
  8. ^ a b Verger R, van Tilbeurgh H, Cambillau C, Bezzine S, Carriere F (1999). "Colipase: structure and interaction with pancreatic lipase". Biochim. Biophys. Acta. 1441 (2–3): 173–184. doi:10.1016/s1388-1981(99)00149-3. PMID 10570245.
  9. ^ Egloff MP, Marguet F, Buono G, Verger R, Cambillau C, van Tilbeurgh H (March 1995). "The 2.46 A resolution structure of the pancreatic lipase-colipase complex inhibited by a C11 alkyl phosphonate". Biochemistry. 34 (9): 2751–62. doi:10.1021/bi00009a003. PMID 7893686.

Further reading

This article incorporates text from the public domain Pfam and InterPro: IPR001981


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