Endopeptidase-24.11 and aminopeptidase activity in brain synaptic membranes are jointly responsible for the hydrolysis of cholecystokinin octapeptide (CCK-8)

FEBS Lett. 1984 Sep 17;175(1):124-8. doi: 10.1016/0014-5793(84)80583-9.


Endopeptidase-24.11 (EC from pig kidney hydrolysed CCK-8 (sulphated) at two distinct sites: Asp-Tyr(SO3H)-Met-Gly Trp-Met-Asp PheNH2. Under initial conditions, the splitting of the Asp7-Phe8NH2 bond proceeded 4-times more rapidly than the Gly4-Trp5 bond. Pig brain striatal synaptic membranes attacked this substrate at the same sites and this activity was inhibited by phosphoramidon. However, other products were detected even in the presence of phosphoramidon. One of these products was identified as free tryptophan. Since their formation was inhibited by bestatin, one or more membrane aminopeptidases is also implicated in the degradation of CCK-8.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aminopeptidases / metabolism*
  • Animals
  • Chromatography, High Pressure Liquid
  • Corpus Striatum / enzymology*
  • Endopeptidases / metabolism*
  • Hydrolysis
  • Neprilysin
  • Sincalide / metabolism*
  • Swine
  • Synaptic Membranes / enzymology*


  • Endopeptidases
  • Aminopeptidases
  • Neprilysin
  • Sincalide