Pterin cofactor, substrate specificity, and observations on the kinetics of the reversible tungsten-containing aldehyde oxidoreductase from Clostridium thermoaceticum

1995 ◽  
Vol 164 (2) ◽  
pp. 110-118 ◽  
Author(s):  
Claudia Huber ◽  
Haike Skopan ◽  
Richard Feicht ◽  
Hiltrud White ◽  
H. Simon
Keyword(s):  
Substrate Specificity ◽  
Clostridium Thermoaceticum ◽  
Aldehyde Oxidoreductase ◽  
Pterin Cofactor ◽  
Kinetics Of

scholarly journals WOR5, a Novel Tungsten-Containing Aldehyde Oxidoreductase from Pyrococcus furiosus with a Broad Substrate Specificity

2005 ◽  
Vol 187 (20) ◽  
pp. 7056-7061 ◽  
Author(s):  
Loes E. Bevers ◽  
Emile Bol ◽  
Peter-Leon Hagedoorn ◽  
Wilfred R. Hagen
Keyword(s):  
Substrate Specificity ◽  
Pyrococcus Furiosus ◽  
Catalytic Efficiency ◽  
Aromatic Aldehydes ◽  
Protein Subunit ◽  
Efficient Catalyst ◽  
Paramagnetic Resonance ◽  
Broad Substrate Specificity ◽  
Aldehyde Oxidoreductase ◽  
Redox Partner

ABSTRACT WOR5 is the fifth and last member of the family of tungsten-containing oxidoreductases purified from the hyperthermophilic archaeon Pyrococcus furiosus. It is a homodimeric protein (subunit, 65 kDa) that contains one [4Fe-4S] cluster and one tungstobispterin cofactor per subunit. It has a broad substrate specificity with a high affinity for several substituted and nonsubstituted aliphatic and aromatic aldehydes with various chain lengths. The highest catalytic efficiency of WOR5 is found for the oxidation of hexanal (V max = 15.6 U/mg, Km = 0.18 mM at 60°C). Hexanal-incubated enzyme exhibits S = 1/2 electron paramagnetic resonance signals from [4Fe-4S]1+ (g values of 2.08, 1.93, and 1.87) and W5+ (g values of 1.977, 1.906, and 1.855). Cyclic voltammetry of ferredoxin and WOR5 on an activated glassy carbon electrode shows a catalytic wave upon addition of hexanal, suggesting that ferredoxin can be a physiological redox partner. The combination of WOR5, formaldehyde oxidoreductase, and aldehyde oxidoreductase forms an efficient catalyst for the oxidation of a broad range of aldehydes in P. furiosus.

scholarly journals Substrate specificity and excision kinetics of natural polymorphic variants and phosphomimetic mutants of human 8-oxoguanine-DNA glycosylase

FEBS Journal ◽  
2009 ◽  
Vol 276 (18) ◽  
pp. 5149-5162 ◽  
Author(s):  
Viktoriya S. Sidorenko ◽  
Arthur P. Grollman ◽  
Pawel Jaruga ◽  
Miral Dizdaroglu ◽  
Dmitry O. Zharkov
Keyword(s):  
Substrate Specificity ◽  
Dna Glycosylase ◽  
Polymorphic Variants ◽  
Kinetics Of

Substrate specificity and kinetics of Candida rugosa lipase in organic media

1996 ◽  
Vol 18 (5) ◽  
pp. 340-346 ◽  
Author(s):  
Anja E.M. Janssen ◽  
Atul M. Vaidya ◽  
Peter J. Halling
Keyword(s):  
Substrate Specificity ◽  
Candida Rugosa ◽  
Candida Rugosa Lipase ◽  
Organic Media ◽  
Kinetics Of

scholarly journals Microtubules and nucleoside diphosphate kinase. Comparison of kinetics of GTP- and CTP-induced assembly

1985 ◽  
Vol 232 (3) ◽  
pp. 657-662 ◽  
Author(s):  
K Islam ◽  
R G Burns
Keyword(s):  
Substrate Specificity ◽  
Kinase Activity ◽  
Nucleoside Diphosphate Kinase ◽  
Elongation Rate ◽  
Microtubule Assembly ◽  
Microtubule Protein ◽  
Assembly Kinetics ◽  
Kinetics Of

The kinetics of assembly of MAP2-tubulin microtubule protein were examined as a function of the GTP concentration in order to test the hypothesis that CTP-induced assembly results from the generation of GTP by nucleoside diphosphate kinase. These studies show that (a) there is no assembly below a minimum GTP concentration and that this represents a nucleation requirement, (b) the rate of elongation is inconsistent with a single assembly-species, and (c) the elongation rate increases markedly as the GTP concentration is raised, although GTP is not absolutely required for elongation. These assembly kinetics have been compared with those with increasing CTP concentrations, by using microtubule protein containing a very low nucleoside diphosphate kinase activity of known substrate specificity. Neither nucleation nor the observed rates of elongation can be attributed to the formation of GTP, either (a) in terms of the generation of free GTP and subsequent binding to tubulin or (b) by the direct charging of GDP bound to the tubulin exchangeable site. The results show that nucleoside diphosphate kinase is not required for CTP-induced microtubule assembly, and suggest that CTP directly effects microtubule assembly.

Substrate Specificity and Kinetics of Candida rugosa Lipase in Organic Media

1996 ◽  
Vol 799 (1 Enzyme Engine) ◽  
pp. 257-261 ◽  
Author(s):  
ANJA E. M. JANSSEN ◽  
ATUL M. VAIDYA ◽  
PETER J. HALLING
Keyword(s):  
Substrate Specificity ◽  
Candida Rugosa ◽  
Candida Rugosa Lipase ◽  
Organic Media ◽  
Kinetics Of
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