Photoaffinity labeling of lipoproteins in human cerebrospinal fluid with a heterobifunctional derivative of galactosylsphingosine.
The binding of a galactosylceramide (GalCer) analog to proteins in normal human cerebrospinal fluid (CSF) was examined by photo-affinity labeling using a radioiodolabeled 2-(p-azido-salicylamido) ethyl-1,3-dithiopropionate (ASD) derivative of galactosylsphingosine (GalSph) as a probe. The affinity-bound peptides appeared at 66, 36 and 28 kDa as radiolabeled bands. The latter two peptides, 36 and 28 kDa, were independently identified by immunostaining of the isolated peptides using biotinylated GalSph, and immobilized Avidin, and by immunoprecipitation of the photolabeled peptide, to apolipoproteins (ALPs) E and A-I, respectively. The direct binding of the GalCer analog to these apo-peptides suggested that the existence in the body fluids or the transfer between the fluids and cells of the glycolipid was related to high density lipoprotein (HDL) constructions.
Chiba
M
M
Department of Neurosurgery, School of Medicine, Sapporo Medical University, Japan.
Tsuchihashi
K
K
Suetake
K
K
Ibayashi
Y
Y
Gasa
S
S
Hashi
K
K
D000345:Affinity Labels; D001710:Biotin; D002352:Carrier Proteins / Q000378:metabolism; D005699:Galactosylceramides / Q000378:metabolism*; D006801:Humans; D008027:Light; D008074:Lipoproteins / Q000134:cerebrospinal fluid / Q000737:chemistry*; D008297:Male; D011485:Protein Binding; D011609:Psychosine / Q000737:chemistry*
D000345:Affinity Labels; D002352:Carrier Proteins; D005699:Galactosylceramides; D008074:Lipoproteins; D011609:Psychosine; D001710:Biotin