Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 1.14.18.1 extracted from

  • Dogan, S.; Salman, U.
    Partial characterization of lettuce (Lactuca sativa L.) polyphenol oxidase (2007), Eur. Food Res. Technol., 226, 93-103.
No PubMed abstract available

Inhibitors

Inhibitors Comment Organism Structure
4-Aminobenzoic acid
-
Lactuca sativa
ascorbic acid
-
Lactuca sativa
glutathione most potent inhibitor for Lactuca sativa L. PPO Lactuca sativa
tropolone
-
Lactuca sativa

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
2000
-
4-methylcatechol
-
Lactuca sativa
2250
-
catechol
-
Lactuca sativa
3000
-
pyrogallol
-
Lactuca sativa

Organism

Organism UniProt Comment Textmining
Lactuca sativa
-
-
-

Purification (Commentary)

Purification (Comment) Organism
partially purified by ammonium sulfate ((NH4)2SO4) precipitation and dialysis Lactuca sativa

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
4-methylcatechol + 1/2 O2 diphenolic substrate Lactuca sativa 4-methyl-1,2-benzoquinone + H2O
-
?
catechol + 1/2 O2 diphenolic substrate Lactuca sativa 1,2-benzoquinone + H2O
-
?
additional information pyrogallol is the most suitable substrate, followed by catechol and 4-methylcatechol. No activity is detected toward L-tyrosine, a monophenolic substrate Lactuca sativa ?
-
?
pyrogallol + 1/2 O2 a triphenolic substrate Lactuca sativa ?
-
?

Synonyms

Synonyms Comment Organism
polyphenol oxidase
-
Lactuca sativa
PPO
-
Lactuca sativa

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
30
-
for 4-methylcatechol and for pyrogallol as substrate Lactuca sativa
40
-
for catechol as substrate Lactuca sativa

Temperature Range [°C]

Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
20 75 thermal inactivation of PPO is investigated at 35, 55 and 75°C. The optimum temperature at 30 and 40°C. PPO activity is also measured at temperatures ranging from 20 to 60°C by using different substrates. The enzyme activity decreases with increasing temperature Lactuca sativa

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
additional information
-
thermal inactivation of PPO is investigated at 35, 55 and 75°C. Results of the heat inactivation studies suggest that PPO belongs to the group of heat-stable enzymes Lactuca sativa

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
additional information
-
optimum pH values for lettuce PPO are determined in pH ranges of 4-9 Lactuca sativa
6.5
-
for 4-methylcatechol as substrate Lactuca sativa
7.5
-
for pyrogallol as substrate Lactuca sativa
8
-
for catechol as substrate Lactuca sativa

Ki Value [mM]

Ki Value [mM] Ki Value maximum [mM] Inhibitor Comment Organism Structure
0.00179
-
glutathione at an inhibitor concentration of 0.0233 mM, with catechol as a substrate, mixed inhibition Lactuca sativa
0.00222
-
glutathione at an inhibitor concentration of 0.02 mM, with catechol as a substrate, mixed inhibition Lactuca sativa
0.00444
-
glutathione at an inhibitor concentration of 0.0133 mM, with catechol as a substrate, mixed inhibition Lactuca sativa
0.0177
-
tropolone at an inhibitor concentration of 0.0333 mM, with 4-methylcatechol as a substrate, mixed inhibition Lactuca sativa
0.0205
-
glutathione at an inhibitor concentration of 0.267 mM, with 4-methylcatechol as a substrate, competitive inhibition Lactuca sativa
0.0259
-
glutathione at an inhibitor concentration of 0.233 mM, with 4-methylcatechol as a substrate, competitive inhibition Lactuca sativa
0.0314
-
tropolone at an inhibitor concentration of 0.133 mM, with 4-methylcatechol as a substrate, mixed inhibition Lactuca sativa
0.0439
-
tropolone at an inhibitor concentration of 0.366 mM, with 4-methylcatechol as a substrate, mixed inhibition Lactuca sativa
0.0477
-
tropolone at an inhibitor concentration of 0.333 mM, with catechol as a substrate, competitive inhibition Lactuca sativa
0.0555
-
glutathione at an inhibitor concentration of 0.167 mM, with 4-methylcatechol as a substrate, competitive inhibition Lactuca sativa
0.0581
-
ascorbic acid at an inhibitor concentration of 0.2 mM, with 4-methylcatechol as a substrate, competitive inhibition Lactuca sativa
0.0607
-
tropolone at an inhibitor concentration of 0.667 mM, with catechol as a substrate, competitive inhibition Lactuca sativa
0.0667
-
ascorbic acid at an inhibitor concentration of 0.0126 mM, with pyrogallol as a substrate, mixed inhibition Lactuca sativa
0.0678
-
ascorbic acid at an inhibitor concentration of 0.233 mM, with 4-methylcatechol as a substrate, competitive inhibition Lactuca sativa
0.0686
-
tropolone at an inhibitor concentration of 2.67 mM, with catechol as a substrate, competitive inhibition Lactuca sativa
0.082
-
ascorbic acid at an inhibitor concentration of 0.1 mM, with 4-methylcatechol as a substrate, competitive inhibition Lactuca sativa
0.1
-
ascorbic acid at an inhibitor concentration of 0.0082 mM, with pyrogallol as a substrate, mixed inhibition Lactuca sativa
0.133
-
ascorbic acid at an inhibitor concentration of 0.057 mM, with pyrogallol as a substrate, mixed inhibition Lactuca sativa
0.133
-
ascorbic acid at an inhibitor concentration of 0.133 mM, with catechol as a substrate, mixed inhibition Lactuca sativa
0.15
-
4-Aminobenzoic acid at an inhibitor concentration of 0.1 mM, with 4-methylcatechol as a substrate, mixed inhibition Lactuca sativa
0.2
-
4-Aminobenzoic acid at an inhibitor concentration of 0.133 mM, with 4-methylcatechol as a substrate, mixed inhibition Lactuca sativa
0.243
-
4-Aminobenzoic acid at an inhibitor concentration of 0.243 mM, with 4-methylcatechol as a substrate, mixed inhibition Lactuca sativa
0.3
-
ascorbic acid at an inhibitor concentration of 0.1 mM, with catechol as a substrate, mixed inhibition Lactuca sativa
0.367
-
ascorbic acid at an inhibitor concentration of 0.0408 mM, with catechol as a substrate, mixed inhibition Lactuca sativa

IC50 Value

IC50 Value IC50 Value Maximum Comment Organism Inhibitor Structure
0.011
-
using pyrogallol as a substrate Lactuca sativa tropolone
0.0114
-
using pyrogallol as a substrate Lactuca sativa glutathione
0.013
-
using catechol as a substrate Lactuca sativa tropolone
0.0167
-
using 4-methylcatechol as a substrate Lactuca sativa glutathione
0.0662
-
using catechol as a substrate Lactuca sativa glutathione
0.0672
-
using pyrogallol as a substrate Lactuca sativa ascorbic acid
0.215
-
using 4-methylcatechol as a substrate Lactuca sativa 4-Aminobenzoic acid
0.22
-
using catechol as a substrate Lactuca sativa ascorbic acid
0.221
-
using 4-methylcatechol as a substrate Lactuca sativa ascorbic acid
0.413
-
using 4-methylcatechol as a substrate Lactuca sativa tropolone
1.52
-
using catechol as a substrate Lactuca sativa 4-Aminobenzoic acid
4.13
-
using pyrogallol as a substrate Lactuca sativa 4-Aminobenzoic acid