Matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometry analysis of blue copper proteins. Azurin and mavicyanin.
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.
Fukuo
T
T
Department of Applied Chemistry, Kansai University, Osaka, Japan.
Kubota
N
N
Kataoka
K
K
Nakai
M
M
Suzuki
S
S
Arakawa
R
R
D001400:Azurin / Q000032:analysis*; D004926:Escherichia coli / Q000737:chemistry; D013058:Mass Spectrometry; D008667:Metalloproteins / Q000032:analysis*; D008970:Molecular Weight; D010940:Plant Proteins / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D008667:Metalloproteins; D010940:Plant Proteins; C022828:mavicyanin protein, Cucurbita pepo; D001400:Azurin