Purification and characterization of DSIP-like material from ovine pineal glands: possible peptide-protein interaction.
The nonapeptide delta-sleep-inducing peptide (DSIP) has been isolated from venous blood of rabbits induced to sleep. Numerous reports have described sleep as well as extra-sleep effects. Radiochemical and immunochemical data suggest a relationship of DSIP with the pineal gland supported by interactions of this peptide with pineal functions such as the serotonin N-acetyltransferase activity. In order to demonstrate the natural occurrence of DSIP-like material associated with high Mr proteins in the ovine pineal, organs were water-extracted and fractionated by ultrafiltration and gel filtration. Radioimmunoassay (RIA) for DSIP-like fragments of the fractions revealed considerable amounts of pineal DSIP-like immunoreactivity (DSIP-LI) apparently existing in small as well as large molecular forms. Acidification of large DSIP-LI forms resulted in the elution from Sephadex G-50 of Mr less than or equal to 1,000 DSIP-like material. This free DSIP-LI form coeluted with the synthetic DSIP nonapeptide from microBondapak C18 on high-performance liquid chromatography. The results, therefore, appear to indicate the presence of a (biospecific) noncovalent intermolecular interaction of DSIP (1-9) with proteins (Mr greater than or equal to 10,000) of the ovine pineal gland.
Noteborn
H P
HP
Department of Organic Chemistry, University of Utrecht, The Netherlands.
Graf
M V
MV
Ernst
A
A
Schoenenberger
G A
GA
Weusten
J A
JA
Ebels
I
I
Salemink
C A
CA
D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003701:Delta Sleep-Inducing Peptide / Q000032:analysis / Q000302:isolation & purification*; D010446:Peptide Fragments / Q000032:analysis; D010870:Pineal Gland / Q000032:analysis*; D011863:Radioimmunoassay; D012756:Sheep; D013050:Spectrometry, Fluorescence
D010446:Peptide Fragments; D003701:Delta Sleep-Inducing Peptide