Amino acid sequence of a basic blue protein from cucumber seedlings [Copper proteins]

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 79; no. 21; pp. 6434 - 6437
• Main Authors: Murata, M, Begg, G.S, Lambrou, F, Leslie, B, Simpson, R.J, Freeman, H.C, Morgan, F.J
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01-11-1982; National Acad Sciences
• Subjects: Absorption spectra; amino acid sequence; Amino acids; Biochemistry; Biological Sciences: Biochemistry; Bromides; Copper; Cucumbers; Cucumis sativus; Hydrolysis; Ligands; Oxidation; Seedlings
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.79.21.6434

The amino acid sequence of a type 1 copper protein, the 96-residue basic blue protein from cucumber seedlings, has been determined by Edman degradation of the intact molecule and of fragments produced by cleavage with cyanogen bromide and with trypsin. The cucumber basic blue protein shows a marked sequence homology with stellacyanin, and to a smaller degree with plastocyanin and azurin. The known copper ligands of plastocyanin and azurin (corresponding to histidine-37, cysteine-84, histidine-87, and methionine-92 in plastocyanin) are present in the cucumber basic blue protein. However, the latter also contains a half-cystine residue analogous to the suggested fourth ligand of stellacyanin, where methionine is absent.