Isolation of a high specific activity pink, monomeric nitrous oxide reductase from Achromobacter cycloclastes

1990 ◽  
Vol 166 (2) ◽  
pp. 729-735 ◽  
Author(s):  
C.L. Hulse ◽  
B.A. Averill
Keyword(s):  
Nitrous Oxide ◽  
Specific Activity ◽  
High Specific Activity ◽  
Nitrous Oxide Reductase ◽  
Achromobacter Cycloclastes

scholarly journals Biochemical characterization of the purple form of Marinobacter hydrocarbonoclasticus nitrous oxide reductase

2012 ◽  
Vol 367 (1593) ◽  
pp. 1204-1212 ◽  
Author(s):  
Simone Dell'Acqua ◽  
Sofia R. Pauleta ◽  
José J. G. Moura ◽  
Isabel Moura
Keyword(s):  
Nitrous Oxide ◽  
Redox State ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Active Species ◽  
Nitrous Oxide Reductase ◽  
Strictly Anaerobic ◽  
Prolonged Incubation ◽  
Redox Active ◽  
Marinobacter Hydrocarbonoclasticus

Nitrous oxide reductase (N 2 OR) catalyses the final step of the denitrification pathway—the reduction of nitrous oxide to nitrogen. The catalytic centre (CuZ) is a unique tetranuclear copper centre bridged by inorganic sulphur in a tetrahedron arrangement that can have different oxidation states. Previously, Marinobacter hydrocarbonoclasticus N 2 OR was isolated with the CuZ centre as CuZ*, in the [1Cu 2+ : 3Cu + ] redox state, which is redox inert and requires prolonged incubation under reductive conditions to be activated. In this work, we report, for the first time, the isolation of N 2 OR from M. hydrocarbonoclasticus in the ‘purple’ form, in which the CuZ centre is in the oxidized [2Cu 2+ : 2Cu + ] redox state and is redox active. This form of the enzyme was isolated in the presence of oxygen from a microaerobic culture in the presence of nitrate and also from a strictly anaerobic culture. The purple form of the enzyme was biochemically characterized and was shown to be a redox active species, although it is still catalytically non-competent, as its specific activity is lower than that of the activated fully reduced enzyme and comparable with that of the enzyme with the CuZ centre in either the [1Cu 2+ : 3Cu + ] redox state or in the redox inactive CuZ* state.

Insight into Catalysis of Nitrous Oxide Reductase from High-resolution Structures of Resting and Inhibitor-bound Enzyme from Achromobacter cycloclastes

2006 ◽  
Vol 362 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Konstantinos Paraskevopoulos ◽  
Svetlana V. Antonyuk ◽  
R. Gary Sawers ◽  
Robert R. Eady ◽  
S. Samar Hasnain
Keyword(s):  
Nitrous Oxide ◽  
High Resolution ◽  
Nitrous Oxide Reductase ◽  
Achromobacter Cycloclastes ◽  
Insight Into

Anaerobic purification, characterization and preliminary mechanistic study of recombinant nitrous oxide reductase from Achromobacter cycloclastes

2007 ◽  
Vol 101 (11-12) ◽  
pp. 1836-1844 ◽  
Author(s):  
Koyu Fujita ◽  
Jeannine M. Chan ◽  
John A. Bollinger ◽  
Marcela L. Alvarez ◽  
David M. Dooley
Keyword(s):  
Nitrous Oxide ◽  
Mechanistic Study ◽  
Nitrous Oxide Reductase ◽  
Achromobacter Cycloclastes

Theoretically exploring the key role of the Lys412 residue in the conversion of N2O to N2by nitrous oxide reductase from Achromobacter cycloclastes

2015 ◽  
Vol 39 (10) ◽  
pp. 8093-8099 ◽  
Author(s):  
Hujun Xie ◽  
Chengcheng Liu ◽  
Xuelin Chen ◽  
Qunfang Lei ◽  
Wenjun Fang ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrous Oxide Reductase ◽  
Achromobacter Cycloclastes ◽  
Back Donation

The active CuZcluster of NOR provides strong back-donation to coordinated N2O and activates the O atom of the N2O group facilitating H-bonding and protonationviathe Lys412 residue.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

Autoprothrombin C Activity from Prothrombin with Snake Venom or Trypsin

1962 ◽  
Vol 08 (03) ◽  
pp. 425-433 ◽  
Author(s):  
Ewa Marciniak ◽  
Edmond R Cole ◽  
Walter H Seegers
Keyword(s):  
Snake Venom ◽  
Thrombolytic Agent ◽  
Sodium Citrate ◽  
Specific Activity ◽  
High Specific Activity ◽  
Citrate Solution ◽  
Clotting Factors ◽  
Activation Products ◽  
Russell’S Viper ◽  
Autoprothrombin C

SummarySuitable conditions were found for the generation of autoprothrombin C from purified prothrombin with the use of Russell’s viper venom or trypsin. DEAE chromatographed prothrombin is structurally altered and has never been found to yield autoprothrombin C and also did not yield it when Russell’s viper venom or trypsin were used. Autoprothrombin C is derived from prothrombin with tissue extract thromboplastin, but not in large amounts with the intrinsic clotting factors. With the latter thrombin and autoprothrombin III are the chief activation products. Autoprothrombin III concentrates were prepared from serum and upon activation with 25% sodium citrate solution or with Russell’s viper venom large amounts of autoprothrombin C were obtained, and this was of high specific activity. Theoretically trypsin is not a thrombolytic agent, but on the contrary should lead to intravascular clotting.

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