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Photoaffinity labelling of melanoma cell MSH receptors
Author(s) -
Scimonelli Teresa,
Eberle Alex N.
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)80566-5
Subject(s) - labelling , receptor , photoaffinity labeling , melanoma , affinity label , stimulation , chemistry , tyrosinase , cell surface receptor , cell , microbiology and biotechnology , biochemistry , biology , endocrinology , enzyme , cancer research
UV‐irradiation at 365 nm of cultured Cloudman S91 mouse melanoma cells in the presence of photoreactive α‐MSH analogues induced longlasting receptor stimulation as revealed by the ensuing activation of tyrosinase. Receptor labelling was more efficient with 4‐diazirinophenyl and 2‐nitro‐4‐azidophenyl photolabels than with 4‐azidophenyl, and was further increased when superpotent [Nle 4 ,D‐Phe 7 ]‐α‐MSH was used as ligand. Incubation of B16 melanoma cell membranes with mono‐iodinated [Nle 4 ,D‐Phe 7 Trp‐(Naps) 9 ]‐α‐MSH followed by UV‐irradiation at 310–550 nm labelled a single band on SD‐PAGE with a molecular mass ⋍ 45 kDa. The displacement curve obtained in a competitive photolabelling experiment paralleled that of the binding assay, demonstrating that the labelling was specific.