CO2, not HCO3-, facilitates oxidations by Cu,Zn superoxide dismutase plus H2O2

被引：57

作者：

Liochev, SI ^{[1
]}

Fridovich, I ^{[1
]}

机构：

[1] Duke Univ, Med Ctr, Dept Biochem, Durham, NC 27710 USA

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2004年 / 101卷 / 03期

关键词：

D O I：

10.1073/pnas.0307635100

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

The Cu,Zn superoxide dismutase catalyzes HCO3--dependent oxidations by H2O2. This activity has been shown to depend on the creation of a bound oxidant at the Cu(II) by interactions with H2O2. The bound oxidant was then thought to oxidize HCO3- to CO3.-, which diffuses into the bulk solution and there oxidizes diverse substrates. We now find that CO2 rather than HCO3- facilitates the peroxidations catalyzed by Cu,Zn superoxide dismutase. This fact was shown by a lag in the rate of peroxidation of NADPH when NaHCO3- was added last and by a burst in the rate when aqueous CO2 was added last. Both the lag and the burst were eliminated by carbonic anhydrase.

引用

页码：743 / 744

页数：2

共 11 条

[1]

COOPER TG, 1968, J BIOL CHEM, V243, P3857

[2] An alternative mechanism of bicarbonate-mediated peroxidation by copper-zinc superoxide dismutase - Rates enhanced via proposed enzyme-associated peroxycarbonate intermediate [J].

Elam, JS ;

Malek, K ;

Rodriguez, JA ;

Doucette, PA ;

Taylor, AB ;

Hayward, LJ ;

Cabelli, DE ;

Valentine, JS ;

Hart, PJ .

JOURNAL OF BIOLOGICAL CHEMISTRY, 2003, 278 (23) :21032-21039

[3] Bicarbonate enhances the peroxidase activity of Cu,Zn-superoxide dismutase - Role of carbonate anion radical [J].

Goss, SPA ;

Singh, RJ ;

Kalyanaraman, B .

JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (40) :28233-28239

[4]

Götz R, 1999, YEAST, V15, P855, DOI 10.1002/(SICI)1097-0061(199907)15:10A<855::AID-YEA425>3.0.CO

[5]

2-C

[6]

LANGE NA, 1961, LANGEW HDB CHEM, P1100

[7] Copper, zinc superoxide dismutase and H2O2 -: Effects of bicarbonate on inactivation and oxidations of NADPH and urate, and on consumption of H2O2 [J].

Liochev, SI ;

Fridovich, I .

JOURNAL OF BIOLOGICAL CHEMISTRY, 2002, 277 (38) :34674-34678

[8]

MOELLER T, 1954, INORGANIC CHEM ADV T, P689

[9] Equilibria, kinetics, and mechanism in the bicarbonate activation of hydrogen peroxide: Oxidation of sulfides by peroxymonocarbonate [J].

Richardson, DE ;

Yao, HR ;

Frank, KM ;

Bennett, DA .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (08) :1729-1739

[10] Bicarbonate is required for the peroxidase function of Cu,Zn-superoxide dismutase at physiological pH [J].

Sankarapandi, S ;

Zweier, JL .

JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (03) :1226-1232

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