title: Sulphated CCK-8-like peptides in the neural ganglion of the protochordate Ciona intestinalis.
abstract: Immunochemical studies were carried out on extracts of the neural ganglion from the ascidian Ciona intestinalis in order to the characterize the peptide(s), which react with antibodies against the C-terminal sequence common for the mammalian hormones, cholecystokinin (CCK) and gastrin. Radioimmunoassays specific for the sulphotyrosyl-containing N-terminus of CCK-8, for the common alpha-carboxyamidated C-terminus and for gastrin were used to monitor gel chromatography and reverse-phase HPLC of the extracts. Only neutral extracts contained immunoreactive material (634 (524-785) pmol eqv.CCK-8/g) (mean and range, n = 4)). HPLC revealed a small peak eluting almost like CCK-8 and a larger peak eluting earlier. By subsequent gel chromatography the larger peak eluted in the same position as sulphated CCK-8. The material was recognized almost equally by the N- and C-terminal CCK radioimmunoassays, whereas the specific C-terminal gastrin radioimmunoassay did not measure the peptides. Treatment with arylsulphatase removed the binding to the antiserum specific for the sulphotyrosyl-containing sequence of CCK. The results indicate that the ganglion of Ciona intestinalis contains a tyrosyl-sulphated peptide resembling mammalian CCK-8.
authors: Clinical Research Group for Gastrointestinal Endocrinology of the Max-Planck-Society, University of Göttingen, F.R.G.
authors: J M
authors: JM
authors: Conlon
authors: T W
authors: TW
authors: Schwartz
authors: J F
authors: JF
authors: Rehfeld
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001192:Arylsulfatases / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002938:Ciona intestinalis / Q000032:analysis*; D005724:Ganglia / Q000032:analysis*; D005755:Gastrins / Q000032:analysis; D007150:Immunohistochemistry; D012844:Sincalide / Q000032:analysis*; D013431:Sulfates / Q000032:analysis; D014561:Urochordata / Q000032:analysis*
chemical_list: D005755:Gastrins; D013431:Sulfates; D001192:Arylsulfatases; D012844:Sincalide