Photoinactivation of Agaricus bisporus tyrosinase: modification of the binuclear copper site

Biochemistry ◽  
1983 ◽  
Vol 22 (21) ◽  
pp. 4949-4953 ◽  
Author(s):  
David C. Fry ◽  
Kenneth G. Strothkamp
Keyword(s):  
Agaricus Bisporus ◽  
Binuclear Copper ◽  
Copper Site

Oxygen Activation by the Noncoupled Binuclear Copper Site in Peptidylglycine α-Hydroxylating Monooxygenase. Spectroscopic Definition of the Resting Sites and the Putative CuIIM−OOH Intermediate†

Biochemistry ◽  
2004 ◽  
Vol 43 (19) ◽  
pp. 5735-5747 ◽  
Author(s):  
Peng Chen ◽  
Joseph Bell ◽  
Betty A. Eipper ◽  
Edward I. Solomon
Keyword(s):  
Oxygen Activation ◽  
Binuclear Copper ◽  
Resting Sites ◽  
Copper Site ◽  
Definition Of

Is phenolate oxygen of a tyrosine resideu the bridging lingad at the binuclear copper site in oxyhemocyanin?

1981 ◽  
Vol 56 ◽  
pp. L33-L34 ◽  
Author(s):  
Jun Kino ◽  
Shinnichiro Suzuki ◽  
Wasuke Mori ◽  
Akitsugu Nakahara
Keyword(s):  
Binuclear Copper ◽  
Copper Site

scholarly journals A new crystal form of Aspergillus oryzae catechol oxidase and evaluation of copper site structures in coupled binuclear copper enzymes

PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0196691 ◽  
Author(s):  
Leena Penttinen ◽  
Chiara Rutanen ◽  
Markku Saloheimo ◽  
Kristiina Kruus ◽  
Juha Rouvinen ◽  
...  
Keyword(s):  
Aspergillus Oryzae ◽  
Crystal Form ◽  
Catechol Oxidase ◽  
Binuclear Copper ◽  
Copper Enzymes ◽  
Copper Site

scholarly journals Spectroscopic evidence for a photosensitive oxygenated state of ammonia mono-oxygenase

1985 ◽  
Vol 226 (2) ◽  
pp. 499-507 ◽  
Author(s):  
J H Shears ◽  
P M Wood
Keyword(s):  
Metal Ion ◽  
Chelating Agents ◽  
Ammonia Oxidation ◽  
Resting Cells ◽  
Organic Substrates ◽  
Copper Proteins ◽  
Binuclear Copper ◽  
Oxidation Activity ◽  
Copper Site ◽  
Electron Reduction

Photoinactivation of ammonia oxidation by Nitrosomonas europaea cells by near-u.v. light was confirmed and further shown to occur with the same rate constant as loss of bromoethane-oxidation activity. Hydroxylamine oxidation was much less photosensitive. Protection against inactivation was afforded by anaerobiosis, organic substrates of ammonia mono-oxygenase such as bromoethane, or metal-ion-chelating agents such as thiourea. The presence of 10 mM-NH4+ or 1 mM-hydroxylamine made little difference, whereas hydrazine had a potentiating effect. Illumination of cells also caused a bleaching in the absorption spectrum around 380 nm, along with changes in the cytochrome gamma-band region. Similar effects below 400 nm were obtained when organic substrates and inhibitors of the mono-oxygenase were added to cells in the dark. The copper proteins haemocyanin and tyrosinase have a photosensitive oxygenated state with a near-u.v. absorption band of similar half-width. They also have a sensitivity to chelating agents similar to that of ammonia mono-oxygenase. The experimental results are explained in terms of a three-stage catalytic cycle analogous to that for tyrosinase. In resting cells most of the enzyme is believed to be in an oxygenated (Oxy) form, which absorbs maximally at 378 nm and is photosensitive. In the presence of a substrate, one O atom is inserted into the substrate and the other is reduced to water, leaving the enzyme in an oxidized (Met) state. This is followed by a two-electron reduction of the proposed binuclear copper site to give a reduced (Deoxy) state, which can bind O2 to complete the cycle.

scholarly journals Involvement of the Binuclear Copper Site in the Proteolytic Activity of Polyphenol Oxidase

1999 ◽  
Vol 40 (10) ◽  
pp. 1029-1035 ◽  
Author(s):  
T. Kuwabara ◽  
Y. Katoh
Keyword(s):  
Proteolytic Activity ◽  
Polyphenol Oxidase ◽  
Binuclear Copper ◽  
Copper Site

Quantitative Cu(I) determination using X-ray absorption edge spectroscopy: Oxidation of the reduced binuclear copper site in type 2 depleted Rhus laccase

1983 ◽  
Vol 112 (2) ◽  
pp. 737-745 ◽  
Author(s):  
James E. Hahn ◽  
Man Sung Co ◽  
Darlene J. Spira ◽  
Keith O. Hodgson ◽  
Edward I. Solomon
Keyword(s):  
Absorption Edge ◽  
Binuclear Copper ◽  
X Ray ◽  
Copper Site ◽  
X Ray Absorption
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