Design and synthesis of a novel biotinylated photoreactive insulin for receptor analysis.
B1-(4-Azido-salicyloyl)-[B1-biocytin,B2-lysine]insulin was synthesized by double Edman degradation of A1,B29-Msc2-insulin and stepwise acylation at the N-terminus of the B-chain. This derivative is homogeneous in RP-HPLC and has a biological in vitro activity of 20% and receptor binding of 15%, relative to insulin. Radioiodination and HPLC gave the B1-labelled 125I-derivative (I) as well as the 4 isomers with 125I-labelled tyrosine (A14, A19, B16, B26). UV-induced crosslinking of I with insulin receptors led to specific labelling of the alpha-subunit (Mr 130,000). The peptide bond LysB2-AspB3 is completely cleavable by trypsin (EC 3.4.21.4). I is thus a new tool for the analysis of the hormone-binding region by making possible the isolation of tryptic, biotinylated receptor fragments labelled by the dipeptide 125I-4-azidosalicyloyl-biocytinyl-Lys.
Fabry
M
M
Deutsches Wollforschungsinstitut, Technischen Hochschule Aachen.
Brandenburg
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D
D000345:Affinity Labels; D001710:Biotin / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D007328:Insulin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D008970:Molecular Weight; D011972:Receptor, Insulin / Q000032:analysis* / Q000378:metabolism
D000345:Affinity Labels; D007328:Insulin; C074609:insulin, B1-(4-azidosalicyloyl)-(B1-biocytin,B2-lysine)-; D001710:Biotin; D011972:Receptor, Insulin