Chemical characterization of rat cholecystokinin-58.
Cholecystokinin-58 (CCK-58) was purified from rat intestines using an extraction method that yields large amounts of this peptide. Greater than 30% of total CCK immunoreactivity eluted before CCK-39 upon gel permeation chromatography (Sephadex G-50) if extracts were loaded onto Sep Pak cartridges before freezing. If the extracts were frozen and stored at -70 degrees C for six weeks, only 20% of the material eluted in this region and total immunoreactivity was reduced by 50%, suggesting that proteases were active under these storage conditions. This early eluting peak was purified by reverse phase and ion-exchange HPLC to a single absorbance peak. Microsequence analysis of this peak detected AVLRPDSEP which is the amino terminus of rat CCK-58 predicted from the rat preprocholecystokinin cDNA. Because degradation of CCK-58 occurred in these extracts, it is possible that CCK-58 is the predominant molecule form in the rat small intestine.
Turkelson
C M
CM
Veterans Administration Medical Center, Kansas City, MO 64128.
Solomon
T E
TE
Bussjaeger
L
L
Turkelson
J
J
Ronk
M
M
Shively
J E
JE
Ho
F J
FJ
Reeve
J R
JR
D000595:Amino Acid Sequence; D000818:Animals; D002766:Cholecystokinin / Q000235:genetics / Q000302:isolation & purification*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D007422:Intestines / Q000032:analysis*; D008297:Male; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000235:genetics; D011863:Radioimmunoassay; D051381:Rats; D011916:Rats, Inbred F344
D021382:Protein Sorting Signals; D004247:DNA; D002766:Cholecystokinin