Purification and sequencing of a rat intestinal 22 amino acid C-terminal CCK fragment

John Eng, Bao Heng Du, Yu Ching E. Pan, May Chang, Jeffrey D. Hulmes, Rosalyn S. Yalow

Research output: Contribution to journalArticlepeer-review

53 Scopus citations


Fractionation on Sephadex G50 gel of methanol extracts of rat intestine revealed two molecular forms of cholecystokinin (CCK) of about equal immunopotency: one form has an elution volume between CCK33 and CCK12; the other elutes in the salt region as does authentic CCK8. Purification and sequencing have demonstrated that the smaller molecular form is CCK8 with a sequence identical to the pork and sheep CCK8's that had previously been sequenced. Purification and sequencing of the larger molecular form reveals that it is a 22 amino acid C-terminal CCK fragment identical with pig CCK22 except that glycine instead of serine is present at the nineteenth residue from the C-terminus. This sequence is consistent with that predicted by cloned cDNA encoding preprocholecystokinin from a rat medullary thyroid carcinoma. CCK22 has not previously been reported to be a prominent molecular form in either pig or dog intestines.

Original languageEnglish
Pages (from-to)1203-1206
Number of pages4
Issue number6
StatePublished - 1984
Externally publishedYes


  • C-terminal fragments
  • CCK post-translational processing
  • Methanol extraction


Dive into the research topics of 'Purification and sequencing of a rat intestinal 22 amino acid C-terminal CCK fragment'. Together they form a unique fingerprint.

Cite this