TY - JOUR
T1 - Affinity labeling of melatonin binding sites in the hamster brain
AU - Anis, Yossi
AU - Zisapel, Nava
N1 - Funding Information:
Acknowledgment: This work was supported in part by the Israel Academy of Sciences and Humanities, Basic Research Foundation.
PY - 1991/8/15
Y1 - 1991/8/15
N2 - N-Bromoacetyl-2-iodo-5-methoxytryptamine (BIM), a novel derivative of the biologically active melatonin analog, 2-iodomelatonin, was used to identify melatonin binding proteins in synaptosomes from Syrian hamster brain. Incubation of the synaptosomes with BIM resulted in a concentration dependent, irreversible inhibition of 2-125I-iodomelationin binding. The radioactive form of BIM, N-Bromoacetyl-2-125I-iodo-5-methoxytryptamine (125I-BIM), became covalently attached to three proteins in the synaptosomes, in a concentration dependent manner. These proteins had apparent molecular weight values of 92, 55 and 45 kilodaltons. The incorporation of 125I-BIM into all three proteins was inhibited by BIM> 2-iodomelatonin> melatonin whereas the melatonin antagonist N-(1,4 dinitrophenyl)-5-methoxytryptamine (ML-23) selectively inhibited the labeling of the 45 kDa protein. These results indicate that the 92, 55 and 45 KDa polypeptides are melatonin binding proteins.
AB - N-Bromoacetyl-2-iodo-5-methoxytryptamine (BIM), a novel derivative of the biologically active melatonin analog, 2-iodomelatonin, was used to identify melatonin binding proteins in synaptosomes from Syrian hamster brain. Incubation of the synaptosomes with BIM resulted in a concentration dependent, irreversible inhibition of 2-125I-iodomelationin binding. The radioactive form of BIM, N-Bromoacetyl-2-125I-iodo-5-methoxytryptamine (125I-BIM), became covalently attached to three proteins in the synaptosomes, in a concentration dependent manner. These proteins had apparent molecular weight values of 92, 55 and 45 kilodaltons. The incorporation of 125I-BIM into all three proteins was inhibited by BIM> 2-iodomelatonin> melatonin whereas the melatonin antagonist N-(1,4 dinitrophenyl)-5-methoxytryptamine (ML-23) selectively inhibited the labeling of the 45 kDa protein. These results indicate that the 92, 55 and 45 KDa polypeptides are melatonin binding proteins.
UR - http://www.scopus.com/inward/record.url?scp=0025946150&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(91)91012-2
DO - 10.1016/0006-291X(91)91012-2
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AN - SCOPUS:0025946150
SN - 0006-291X
VL - 178
SP - 1147
EP - 1152
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -