Combined deficiency of xanthine oxidase and sulphite oxidase due to a deficiency of molybdenum cofactor

1996 ◽  
Vol 19 (5) ◽  
pp. 700-701 ◽  
Author(s):  
E. Bonioli ◽  
A. DiStefano ◽  
A. Palmieri ◽  
A. Bertola ◽  
C. Bellini ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Molybdenum Cofactor ◽  
Sulphite Oxidase ◽  
Combined Deficiency

Attempt at treatment with tetrahydrobiopterin in combined deficiency of xanthine oxidase and sulphite oxidase

1991 ◽  
Vol 14 (5) ◽  
pp. 843-844 ◽  
Author(s):  
M. Fujitaka ◽  
N. Sakura ◽  
K. Ueda ◽  
H. Konishi ◽  
S. Yoshida ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Sulphite Oxidase ◽  
Combined Deficiency

scholarly journals Combined deficiency of sulfite oxidase and xanthine oxidase as a result of defective synthesis of molybdenum-cofactor: 77

1980 ◽  
Vol 14 (2) ◽  
pp. 177-177 ◽  
Author(s):  
M Duran ◽  
F A Beemer ◽  
S K Wadman ◽  
J L Johnson ◽  
W R Waud ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Sulfite Oxidase ◽  
Molybdenum Cofactor ◽  
Combined Deficiency

scholarly journals Quantitative transfer of the molybdenum cofactor from xanthine oxidase and from sulphite oxidase to the deficient enzyme of the nit-1 mutant of Neurospora crassa to yield active nitrate reductase

1984 ◽  
Vol 219 (2) ◽  
pp. 481-493 ◽  
Author(s):  
T R Hawkes ◽  
R C Bray
Keyword(s):  
Nitrate Reductase ◽  
Neurospora Crassa ◽  
Xanthine Oxidase ◽  
Specific Activity ◽  
Reductase Activity ◽  
Molybdenum Cofactor ◽  
Alternative Methods ◽  
High Yield ◽  
Assay Method ◽  
Sulphite Oxidase

An assay method is described for measurement of absolute concentrations of the molybdenum cofactor, based on complementation of the defective nitrate reductase (‘apo nitrate reductase’) in extracts of the nit-1 mutant of Neurospora crassa. A number of alternative methods are described for preparing, anaerobically, molybdenum-cofactor-containing solutions from sulphite oxidase, xanthine oxidase and desulpho xanthine oxidase. For assay, these were mixed with an excess of extract of the nit-1 mutant, incubated for 24 h at 3.5 degrees C then assayed for NADPH:nitrate reductase activity. In all cases, the specific activity of the molybdenum cofactor, expressed as mumol of NO2-formed/min per ng-atom of Mo added from the denatured molybdoenzyme, was 25 +/- 4, a value that agrees with the known catalytic activity of the nitrate reductase of wild-type Neurospora crassa. This indicates that, under our conditions, there was quantitative transfer of the molybdenum cofactor from denatured molybdoenzyme to yield fully active nitrate reductase. Comparable cofactor assay methods of previous workers, apparently indicating transfer efficiencies of at best a few per cent, have never excluded satisfactorily the possibility that cofactor activity arose, not from stoichiometric constituents of the molybdoenzymes, but from contaminants. The following factors were investigated separately in developing the assay:the efficiency of extraction of the cofactor from the original enzyme, the efficiency of the complementation reaction between cofactor and apo nitrate reductase, and the assay of the resultant nitrate reductase, which must be carried out under non-inhibitory conditions. Though the cofactor is unstable in air (t1/2 about 15 min at 3.5 degrees C), it is stable when kept anaerobic in the presence of sodium dithionite, in aqueous solution or in dimethyl sulphoxide (activity lost at the rate of about 3%/24 h at 20-25 degrees C). Studies of stabilities, and investigations of the effect of added molybdate on the assay, permit conclusions to be drawn about the ligation of molybdenum to the cofactor and about steps in incorporation of the cofactor into the apoenzyme. Though the development of nitrate reductase activity is slow at 3.5 degrees C (t1/2 1.5-3 h) the complementation reaction may be carried out in high yield, aerobically. This is ascribed to rapid formation of an air-stable but catalytically inactive complex of the cofactor, as a precursor of the active nitrate reductase.(ABSTRACT TRUNCATED AT 400 WORDS)

Combined deficiency of xanthine oxidase and sulphite oxidase: Diagnosis of a new case followed by an antenatal diagnosis

1985 ◽  
Vol 8 (S2) ◽  
pp. 117-118 ◽  
Author(s):  
P. Desjacques ◽  
B. Mousson ◽  
C. Vianey-Liaud ◽  
R. Boulieu ◽  
C. Bory ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Antenatal Diagnosis ◽  
Sulphite Oxidase ◽  
Combined Deficiency

Combined deficiency of xanthine oxidase and sulphite oxidase: A defect of molybdenum metabolism or transport?

1978 ◽  
Vol 1 (4) ◽  
pp. 175-178 ◽  
Author(s):  
M. Duran ◽  
F. A. Beemer ◽  
C. v. d. Heiden ◽  
J. Korteland ◽  
P. K. de Bree ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Sulphite Oxidase ◽  
Combined Deficiency

Prenatal diagnosis of molybdenum cofactor deficiency by assay of sulphite oxidase activity in chorionic villus samples

1991 ◽  
Vol 14 (6) ◽  
pp. 932-937 ◽  
Author(s):  
J. L. Johnson ◽  
K. V. Rajagopalan ◽  
J. T. Lanman ◽  
R. B. H. Schutgens ◽  
A. H. van Gennip ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Oxidase Activity ◽  
Chorionic Villus ◽  
Molybdenum Cofactor ◽  
Molybdenum Cofactor Deficiency ◽  
Sulphite Oxidase ◽  
Cofactor Deficiency
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