Information on EC 1.7.3.3 - factor-independent urate hydroxylase

for references in articles please use BRENDA:EC1.7.3.3
Word Map on EC 1.7.3.3
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Select one or more organisms in this record:


The expected taxonomic range for this enzyme is: Eukaryota, Bacteria, Archaea

EC NUMBER
COMMENTARY hide
1.7.3.3
-
RECOMMENDED NAME
GeneOntology No.
factor-independent urate hydroxylase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
urate + O2 + H2O = 5-hydroxyisourate + H2O2
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
oxidation
redox reaction
-
-
-
-
reduction
-
-
-
-
additional information
-
the enzyme catalyzes the degradation of urate to [S]-allantoin through 5-hydroxyisourate as a metastable intermediate
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
urate conversion to allantoin I
-
-
allantoin degradation
-
-
Purine metabolism
-
-
Caffeine metabolism
-
-
Metabolic pathways
-
-
Microbial metabolism in diverse environments
-
-
SYSTEMATIC NAME
IUBMB Comments
urate:oxygen oxidoreductase
This enzyme was previously thought to be a copper protein, but it is now known that the enzymes from soy bean (Glycine max), the mould Aspergillus flavus and Bacillus subtilis contains no copper nor any other transition-metal ion. The 5-hydroxyisourate formed decomposes spontaneously to form allantoin and CO2, although there is an enzyme-catalysed pathway in which EC 3.5.2.17, hydroxyisourate hydrolase, catalyses the first step. The enzyme is different from EC 1.14.13.113 (FAD-dependent urate hydroxylase).
CAS REGISTRY NUMBER
COMMENTARY hide
9002-12-4
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
-
-
-
Manually annotated by BRENDA team
NH-Rockefeller strain
UniProt
Manually annotated by BRENDA team
NH-Rockefeller strain
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
soil isolate
-
-
Manually annotated by BRENDA team
-
C5HDG5
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
TB-90
-
-
Manually annotated by BRENDA team
subspecies subtilis LMD 69.3
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
atlantic cod
Uniprot
Manually annotated by BRENDA team
partial sequence
DQ887577
GenBank
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Atlantic halibut
Uniprot
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
African lungfish
Uniprot
Manually annotated by BRENDA team
gene of a clinical isolate. The nucleotide sequence is identical to the coding sequence of gene puuD of Pseudomonas aeruginosa PAO1
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
Uniprot
Manually annotated by BRENDA team
-
JX083378
GenBank
Manually annotated by BRENDA team
-
JX083378
GenBank
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
yeast-like fungi
endosymbiont of Nilaparvata lugens
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
maize
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
physiological function
-
ancestral uricases have steadily decreased in activity since the last common ancestor of mammals gave rise to descendent primate lineages. This progressive decrease is correlated with physiological function and (potential) adaptation. Analysis of the 3D distribution of amino acid replacements as they accumulated during evolutionary history
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
5-hydroxyisourate + O2
(S)-allantoin + H2O2 + CO2
show the reaction diagram
-
-
-
?
urate + O2 + H2O
5-hydroxyisourate + H2O2
show the reaction diagram
uric acid + O2 + H2O
5-hydroxyisourate + H2O2
show the reaction diagram
-
purine degradation
-
-
?
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
urate + O2 + H2O
5-hydroxyisourate + H2O2
show the reaction diagram
uric acid + O2 + H2O
5-hydroxyisourate + H2O2
show the reaction diagram
-
purine degradation
-
-
?
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
-
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Ca2+
-
strong activation at 10 mM
CaCl2
-
enhances activity
Co2+
-
-
copper
Fe3+
-
activates
K+
-
slight activation at 10 mM
Mn2+
2 mM, 170% of initial activity
Na+
-
slight activation at 10 mM
NaCl
-
enhances activity
NH4Cl
-
slight activation at 10 mM
additional information
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
1,3,7-Trimethylxanthine
-
i.e. caffeine, slight
2,2'-dipyridyl
2,9-Dimethyl-1,10-phenanthroline
2-Hydroxypurine
-
-
3,7-Dimethylxanthine
-
i.e. theobromine, slight
3-Methyluric acid
-
-
5,5'-dithiobis(2-nitrobenzoate)
-
-
5-Azaorotate
7-Methyluric acid
-
-
8-Azaxanthine
8-nitroxanthine
-
-
9-methyluric acid
adenine
Allantoic acid
-
weak
allantoin
Amelide
-
-
-
arginine
-
weak
aspartic acid
-
slight
beta-mercaptoethanol
-
about 60% residual activity after 1 h incubation with 0.5 mM beta-mercaptoethanol at pH 8.5 and 25C
Biguanidine salts
-
inactivation is pH-dependent: slightly inhibitory below pH 10, rapid inactivation at high pH
Ca2+
JX083378
1 mM, 20% residual activity
Cyanurate
-
-
D-sorbitol
-
about 70% residual activity after 1 h incubation with 0.5 mM D-sorbitol at pH 8.5 and 25C
Dicyandiamide
-
inactivation is pH-dependent: small below pH 10, rapid increase at high pH
diethyldithiocarbamic acid
-
-
glutamine
glycerol
-
-
glyoxylic acid
-
weak
Guanidinium salts
-
inactivation is pH-dependent: slightly inhibitory below pH 10, rapid inactivation at high pH
H2O2
-
purified uricase retains 72% of its original activity after incubation with 0.5% H2O2 for 6 h
hydroxylamine
-
-
Hydroxypurines
-
-
-
hypoxanthine
inosine 5'-monophosphate
-
-
iodoacetate
-
low effect
Li+
-
18.5% inhibition at 1 mM
N-ethylmaleimide
neocuproin
o-Iodosobenzoate
-
-
o-phenanthroline
oxonate
Oxopurines
-
-
-
p-chloromercuribenzoate
Periodate
-
-
phosphate
-
no inactivation by phosphate, in presence of borate or dithiothreitol
pyrazinoate
Salicylhydroxamic acid
-
-
sodium deoxycholate
-
about 90% residual activity after 1 h incubation with 0.5 mM sodium deoxycholate at pH 8.5 and 25C
Thiourea
-
slight
Trichloropurine
Tween-80
-
0.5% w/v, 61% residual activity
Urate
xanthine
ZnCl2
-
1 mM, 91% inhibition
additional information
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
uric acid
DQ887577
uric acid (0.3%) is an inducer for uricase production, concentrations higher than 0.3% do not enhance the enzyme productivity
additional information
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.08
H2O2
-
25C, pH not specified in the publication
0.029 - 0.061
O2
0.0000135 - 1.05
Urate
0.00588 - 1.5
uric acid
additional information
Urate
-
Km value for degradation of urate crystals is 7 microg/ml, 30C, pH not specified in the publication; Km value for degradation of urate crystals is 9 microg/ml, 30C, pH not specified in the publication
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
9.3
H2O2
-
25C, pH not specified in the publication
3.01 - 21800
Urate
31.3
uric acid
-
-
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
510 - 276000
Urate
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0021
8-nitroxanthine
-
competitive inhibitor versus urate at pH 8.0
0.008
oxonate
-
unmodified enzyme, 50 mM borate buffer, 25C, pH 9.2
0.041 - 4.5
xanthine
additional information
additional information
-
1-methylurate, 3-methylurate, 7-methylurate do not inhibit significantly
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.067
-
wild-type, pH 8.9, 25C
2.49
-
urate oxidase including p-azido-L-phenylalanine instead of Phe at position 281, in 0.1 M borate, pH 8.4
2.67
-
recombinant strain overexpressing the enzyme, pH 8.9, 25C
2.99
mutant A89T/G91A7V92M/H245L/E252A/M253I/R291K/A296V/A301S/K303R, pH 8.6, 25C
3.74
-
cotyledons, 4 d old
4.22
wild-type, pH 8.6, 25C
4.91
mutant H245L/E252A/M253I/R291K/A296V/A301S/K303R, pH 8.6, 25C
5.32
-
purified enzyme
5.68
mutant A296V, pH 8.6, 25C
5.94
mutant R291K/A296V/A301S/K303R, pH 8.6, 25C
6.8
-
wild-type, pH 9.2, 27C
6.85
-
-
8.26
-
urate oxidase including p-azido-L-phenylalanine instead of Phe at position 170, in 0.1 M borate, pH 8.4
8.3
-
mutant L1711I/Y182F/Y187F/A193S, pH 9.2, 27C
9.35
-
male rats
10.5
-
in the cell lysate
13.3
-
hypocotyls, 4 d old
15
pH not specified in the publication, temperature not specified in the publication
15.3
-
female
15.4
-
roots, 4 d old
16.33
-
natural uricase, in 0.1 M borate, pH 8.4
18
-
crude extract, pH 8.0, 37C
21.5
-
after DEAE Sepharose FF chromatography
25.7
-
after Phenyl-Sepharose FF chromatography
27
-
after HiLoad 26/60 Superdex 75 gel filtration
38.4
recombinant protein, pH 8.0, 37C
39
-
after 2.1fold purification, pH 8.0, 37C
1790
-
nodules, 21 d old
additional information
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.5
-
yield of recombinant uricase is significantly improved by the combined use of a high cell-density cultivation technique and a pH control strategy of switching culture pH from 5.5 to 6.5 in the induction phase
7
DQ887577
optimal pH for uricase production in culture flasks
8 - 8.5
-
borate and phosphate buffer
8.2
-
-
8.4
-
assay at
8.5 - 9.3
-
-
8.6
-
free enzyme
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6
JX083378
more than 80% of maximum activity
6.5 - 9.5
-
free uricase shows at least 50% relative activity between pH 6.5 and 9.5, around pH 7.5, free uricase remains 81.16% of its maximum activity, while the uricase loaded in the lipid vesicles remains almost the same high activity (178.26%) as its optimum activity (179.72%)
6.5 - 11
-
pH 6.5: about 40% of maximal activity, pH 10.0: about 50% of maximal activity
7 - 11
-
pH 7: about 50% of activity maximum, pH 11: about 40% of activity maximum
7.4 - 9.6
-
50% of activity maximum at pH 7.4 and pH 9.6, free enzyme
7.5 - 8.5
-
-
8 - 10.2
-
pH 8.0: about 35% of activity maximum, pH 10.2: about 55% of activity maximum
8 - 11
-
50% of activity maximum at pH 8 and pH 11, immobilized enzyme
8.5 - 10.5
-
50% of activity maximum at pH 8.5 and pH 10.5
8.6 - 9.5
-
-
9
JX083378
more than 80% of maximum activity
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
20 - 50
-
20C: about 70% of activity maximum; 50C: about 60% of activity maximum
20 - 70
-
free uricase shows at least 50% relative activity between 20 and 70C
20 - 50
-
20C: about 60% of activity maximum; 50C: about 50% of activity maximum
20 - 55
-
20C: about 80% of maximal activity, maximal activity at 30C, 55C: about 55% of maximal activity
35 - 60
-
-
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4.96
-
isoelectric focusing, pH gradient 3.5-9.5
6.8
-
calculated and isoelectric focusing
7.6
-
isoelectric focusing, rasburicase
8.46
-
determined by means of P/ACE 5000
9.38
calculation from nucleotide sequence
additional information
-
isoelectric focusing presents a trail of pI values between 6.55 and 7.6
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
-
strain CGMCC 2.120 is used as source of uricase gene
Manually annotated by BRENDA team
-
wild-type and PEX5-defective CHO cell lines each stable producing the enzyme
Manually annotated by BRENDA team
-
no uricase is detected in mycelium grown in minimal medium containing NH4Cl as sole nitrogen source. Uricase activity is increased 10fold to 40fold under derepression conditions and is induced by exogenous uric acid
Manually annotated by BRENDA team
-
-
Manually annotated by BRENDA team
additional information
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
-
the enzyme is mainly localized in the membrane of PEX5-defective mutant cells
Manually annotated by BRENDA team
PDB
SCOP
CATH
ORGANISM
UNIPROT
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
18000
-
x * 39700, isoform UI, x * 3050, isoform UII, x * 55300, isoform UIII, x * 18000, isoform UIV, SDS-PAGE
30000
-
alpha4, 4 * 30000, SDS-PAGE
32000 - 35000
-
SDS-PAGE, gel filtration
32880
yeast-like fungi
-
deduced from nucleotide sequence of cDNA
33270
-
determination of nucleotide sequence of cDNA and calculation of corresponding amino acid sequence
33750
-
4 * 33750, X-ray crystallography
33858
-
4 * 33858, calculation from nucleotide sequence
34160
x * 34160, MALDI-TOF
35000
-
alpha2beta2, 2 * 35000 + 2 * 37000, SDS-PAGE
35050
-
deduced from nucleotide sequence of cDNA
35052
-
alpha4, 4 * 35052, calculated from deduced amino acid sequence
35060
-
MALDI-TOF mass spectrometry
35780
-
MALDI-TOF mass spectrometry
35790
-
calculated from amino acid sequence
39000
-
alpha2beta2, 2 * 36000 + 2 * 39000, SDS-PAGE
39700
-
x * 39700, isoform UI, x * 3050, isoform UII, x * 55300, isoform UIII, x * 18000, isoform UIV, SDS-PAGE
50000
-
gel filtration
55300
-
x * 39700, isoform UI, x * 3050, isoform UII, x * 55300, isoform UIII, x * 18000, isoform UIV, SDS-PAGE
58680
-
MALDI-TOF mass spectrometry
58900
-
calculated from amino acid sequence
60000
-
about 60000 Da, SDS-PAGE
62000
-
x * 62000, rasburicase, SDS-PAGE
64000
-
1 * 64000
68000
-
gel filtration
70000 - 76000
-
gel filtration
98000
-
x * 98000, uricase-MBP fusion protein
100000
102000
-
polyacrylamide disc electrophoresis
105000
-
gel filtration
109000
-
gel filtration
114000 - 128000
-
PAGE, gel filtration
115000 - 123000
-
PAGE, gel filtration
117000
-
gel filtration
120000 - 122000
120000 - 140000
-
PAGE, gel filtration
120000
-
gel filtration, equilibrium sedimentation
124000
125000
128000
136300 - 141600
-
ultracentrifugation
137000
-
for the homotetramer, determined by neutron crystallographic analysis
144000
-
native enzyme, gel filtration
145000 - 150000
-
gel filtration
151000
-
Sephadex G-200 gel filtration
230000
-
gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
heterotetramer
hexamer
-
alpha6, 6 * 37000, SDS-PAGE
homotetramer
monomer
tetramer
trimer
-
alpha3, 3 * 32000, SDS-PAGE
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
crystallizations are performed using the hanging-drop vapour-diffusion method at 19.9C, structures of crystals soaked with the substrate uric acid, the inhibitor 8-azaxanthin and allantoin are determined at 1.9-2.2 A resolution, 2 homotetramers comprise the asymmetric crystallographic unit, each subunit contains 2 T-fold domains of topology, which are usually found in purine- and pterin-binding enzymes, the uric acid substrate is bound tightly to the enzyme by interactions with Arg180, Leu222 and Gln223 from one subunit and with Thr67 and sp68 of the neighbouring subunit in the tetramer
; Rasburicase
-
crystallization of large proteins in the presence of polyethylene glycol
-
crystals of about a few tens of micrometres in size, which is nucleated previously in crystallization batch containing 5% PEG 8000, 100 mM NaCl, 8 mg/ml uox-substrate complex and 100 mM Tris-HCl pH 8.5, are used as seeds and their size and quality are further improved using a temperature-control device, large crystals of Uox, co-crystallized with its substrates analogues 8-azaxanthine, 9-methyluric acid or the natural substrate in the presence of cyanide (0.5-2 mg/ml), and soaks with the natural substrate in the absence of cyanide, diffracting to high resolutions are obtained, in the presence of different inhibitors, the crystal form of Uox has a body-centred orthorhombic symmetry and one of the largest primitive unit-cell volumes (a: 80 A, b: 96 A, c: 106 A)
-
enzyme in complex with substrate urate and inhibitor cyanide, X-ray diffraction structure determination and analysis
-
hanging drop vapour diffusion method
-
ligand-free Uox crystallized with NH4Cl and 15% (w/v) PEG 8000, ligand-free Uox crystallized in water with 10% (w/v) PEG 8000, ligand-free Uox crystallized with NaCl and 15% (w/v) PEG 8000, ligand-free Uox crystallized with (NH4)2SO4 and 15% (w/v) PEG 8000, ligand-free Uox crystallized with NaCl and 8% PEG 8000, ligand-free Uox crystallized with KCl and 10% (w/v) PEG 8000, and Uox complexed with 8-azaxanthine and crystallized with NaCl and 10% (w/v) PEG 8000, in 50 mM Tris buffer pH 8.0
-
quantum mechanical/molecular mechanical calculations based on PDB entry 4N9M. The oxidation consists of chemical transformation from 8-hydroxyxythine to an anionic radical via a proton transfer along with an electron transfer, proton transfer to the O2- anion (radical), diradical recombination to form a peroxo intermediate, and dissociation of H2O2 to generate the dehydrourate. Hydration is initiated by the nucleophilic attack of a water molecule on dehydrourate, along with a concerted proton transfer through residue Thr69 in the catalytic site. Hydration is the rate-determining step
-
recombinant enzyme in complex with inhibitor 8-azaxanthine in presence of O2 or Cl-, batch technique at room temperature, 10-15 mg/ml protein with an excess of 0.5-2 mg/ml of 8-azaxanthin in 50 mM Tris/HCl, pH 8.5, in the presence of 5-8% w/v PEG 8000 and 0.05 M NaCl, 24-48 h, X-ray diffraction structure determination and analysis at 1.6-1.7 A resolution
-
sitting drop vapour diffusion method
-
sitting drop vapour diffusion method using buffered D2O
-
sitting-drop vapour-diffusion method at room temperature
-
sitting-drop vapour-difusion method. Four different crystal forms of Uox are analyzed. In the presence of uracil and 5,6-diaminouracil crystals usually belong to the trigonal space group P3(1)21, the asymmetric unit of which contains one tetramer of Uox. Chemical oxidation of 5,6-diaminouracil within the protein may occur, leading to the canonical (I222) packing with one subunit per asymmetric unit. Coexistence of two crystal forms, P2(1) with two tetramers per asymmetric unit and I222, is found in the same crystallization drop containing another inhibitor, guanine. A fourth form, P2(1)2(1)2 with one tetramer per asymmetric unit, results in the presence of cymelarsan, an additive
-
structure to 1.4 A resolution, showing a homotetramer containing two homodimers. In each homodimer H-bonds are found between residues E311 and Y249 and between Y319 and D257. Electrostatic interaction networks surround D307 plus R310 and intersubunit R3, K312 plus D257, E318 plus K242, and L322 plus R258
-
homology modeling of monomeric enzyme. The highly conserved residue Gly290 could interact with Asn262 and His264. Residue substitutions near Gly290 may affect its spatial orientation and result in changes in catalysis.Gly290 is likely to participate in the structure of the active site and to be involved in oxygen-binding
to 1.93 A resolution. Space group P212121 with unit cell parameters a 69.16 A, b 139.31 A, c 256.33 A, and alpha =beta =gamma =90
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6 - 11
-
35C, 1 h, stable
394144
6.5 - 10.5
-
22C, 30 min, immobilized enzyme, stable
394156
7
-
UOX is deactivated at different protein concentrations at 45C in 20 mM phosphate containing 0.15 M NaCl, 0.01 mg/ml UOX is deactivated much faster than its counterparts at concentrations of 0.1 and 1.0 mg/ml
700631
7 - 10
-
-
743753
7 - 11
-
10 min, stable
394178
7 - 9.5
-
in case of uricase entrapped in lipid vesicles, the remaining activity keeps more than 90% during the pH of 7.0-9.5, and the maximum remaining activity is 98.04% at pH 8.0 when incubated at 40C or 40 min. For the free uricase, the maximum remaining activity is 86.59% at pH 8.5 when incubated at 40C or 40 min
712197
7 - 10
-
purified enzyme, 25C, 18 h, stable
701416
7.4
-
37C, stable for 4 days, in presence of 30 microM oxonate stable for 22 days, with exponential decrease of activity thereafter
743752
8 - 11
-
4C, 60 days, 35% loss of activity
394132
8 - 9
-
45C, 30 min, stable
394146
8.5 - 11
-
stable
659535
9.2
-
37C, stable for 12 days, in presence of 30 microM oxonate stable for 22 days, with exponential decrease of activity thereafter
743752
10
-
45C, 30 min, 30% loss of activity
394146
11
-
25C, 18 h, about 60% loss of activity
701416
12
-
22C, 30 min, 55% loss of activity
394156
additional information
-
uricase activity in 50 h culture broth with pH values of 5.5 and 6.0 decreases more rapidly than that in cultures with pH values of 6.5 and 7.0, at pH 5.5, about 78% of initial uricase activity is lost within 25 h, under the same conditions, more than 85% of initial uricase activity remains in culture broth of pH 6.5 and 7.0, uricase activity in 66 h culture broth with pH 7.0 degrades much more rapidly than that in samples from 50 h culture, while for pH 6.5, the uricase is still stable, loss of uricase activity is caused by the degradation in acidic environment by proteases secreted by the host cells or releases from host cell lyses, low pH may cause instability of uricase
695795