ISSN:
0952-3499
Schlagwort(e):
photo-affinity albelling
;
receptors
;
melanocyte stimulating hormone (MSH)
;
melanophore
;
agonism
;
antagonism
;
Chemistry
;
Biochemistry and Biotechnology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Medizin
Notizen:
Photocrosslinking of receptor for α-melanocyte-stimulating hormone (α-MSH) on melanophores of frogs and lizards has been shown to induce long-lasting receptor stimulation whereby the photoreactive α-MSH may contain one or two photolables in positions 1, 7, 9, or 13. The chemical synthesis and biological testing of an α-MSH analogue is now described which contains three photoreactive groups in positions 1, 9 and 13, on eof which with a cleavable S—S disulphide bridge: [ApSSpr-Ser1, Trp(Naps)9 Pap13]-α-MSH. Photocrosslinking of MSH receptors on melanophores of Anolis carolinensis with this analogue led to almost complete receptor blockade which could be transformed into long-lasting receptor stimulation by exposure to a thiol reagents. By contrast, the analogue containing only two photoreactive groups in positions 9 and 13, [Trp(Naps)9, Pap13]-α-MSH, produced long-lasting receptor stimulation which was not altered by the thiol reagent. These results demonstrate that one and the same peptide ligand may contain structural information for both receptor activation and inhibition and that the receptor may become arrested in an activated or inhibited state by multiple photocrosslinking, depending on the relative positions of these crosslinks.
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jmr.300080108
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