Matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometry analysis of blue copper proteins. Azurin and mavicyanin

✍ Scribed by Tsuyoshi Fukuo; Naoko Kubota; Kunishige Kataoka; Masami Nakai; Shinnichirou Suzuki; Ryuichi Arakawa

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 58 KB
• Volume: 12
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19981215)12:23<1967::aid-rcm422>3.0.co;2-1

✦ Synopsis

Two copper proteins azurin-1 and azurin-2 were isolated from denitrifying bacteria Alcaligenes xylosoxidans GIFU1051, and the mass spectrometric analysis of the proteins were carried out by both matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and electrospray ionization (ESI). The mass spectrometric analysis was also carried out with the recombinant zucchini protein mavicyanin, which was obtained by expression in Escherichia coli. All the proteins were detected as positive ions with the copper atom being eliminated. The molecular weights were determined as 14 017.6 for azurin-1, 13 807.6 for azurin-2 and 11 808.8 for mavicyanin. The observed molecular weight of azurin-1 agrees within two daltons with that calculated from the amino acid composition. Azurin-2 was found to have one different amino acid residue when compared with the known azurin-2 isolated from A. xylosoxidans NCIB11015. The measured molecular weight for the recombinant mavicyanin agrees within two daltons with that of calculated from the amino acid composition of the native protein; therefore, the recombinant mavicyanin is identical to the native protein.