High affinity receptors for vasoactive intestinal peptide on a human glioma cell line

Journal Article · Wed Oct 31 23:00:00 EST 1990 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(90)90156-Y· OSTI ID:5801915

Nielsen, F C; Gammeltoft, S; Westermark, B; Fahrenkrug, J ^[1]

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1. Bispebjerg Hospital, Copenhagen NV (Denmark)

Vasoactive intestinal peptide (VIP) bound with high affinity (Kd 0.13 nmol/l) to receptors on the human glioma cell line U-343 MG Cl 2:6. The receptors bound the related peptides helodermin, PHM and secretin with 10, 400 and 5000 times lower affinity, respectively. Deamidated VIP (VIP-COOH) and (des-His1)VIP bound with 10 and 100 times lower affinity. The fragment VIP(7-28) displaced 25% of the receptor-bound {sup 125}I-VIP whereas VIP(16-28) and VIP(1-22-NH2) were inactive. The binding of {sup 125}I-VIP could be completely inhibited by 10 mumol/l of the antagonists (N-Ac-Tyr1,D-Phe2)GRF(1-29)-NH2, (pCl-D-Phe6,Leu17)VIP and VIP(10-28); in contrast, the antagonist L-8-K was inactive. Affinity labeling showed that VIP bound to proteins with Mr's of 75 kDa, 66 kDa and 50 kDa, respectively. Following binding, the peptide was rapidly internalized, and at steady-state only 20% of cell-associated {sup 125}I-VIP was bound to receptors on the cell surface. The internalized {sup 125}I-VIP was completely degraded to {sup 125}I-tyrosine which was released from the cells. Degradation of internalized {sup 125}I-VIP was significantly reduced by chloroquine phenanthroline and pepstatin-A. Surface binding and internalization of {sup 125}I-VIP was increased 3 times by phenanthroline, and pepstatin-A caused a 5 times increase in surface binding. Chloroquine reduced surface-bound {sup 125}I-VIP, but caused retention of internalized {sup 125}I-VIP.

• OSTI ID: 5801915
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:6; ISSN 0196-9781; ISSN PPTDD
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENZYME INHIBITORS
GLIOMAS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LYSOSOMES
MAMMALS
MAN
MEMBRANE PROTEINS
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
PEPTIDES
PRIMATES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
TUMOR CELLS
VERTEBRATES