Application | Comment | Organism |
---|---|---|
food industry | browning in fruits and vegetables is recognized as a serious problem in the food industry. Further studies are warranted to understand the PPO inhibitor in relation to the browning reaction of fruit during storage and processing | Malpighia glabra |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
2-mercaptoethanol | evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
CaCl2 | evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
EDTA | evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
L-ascorbate | significantly inhibits PPO activity, evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
L-cysteine | significantly inhibits PPO activity, evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
Sodium azide | evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
Sodium diethyl dithiocarbamate | SDDC, significantly inhibits PPO activity, evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate. Inhibitors such as sodium diethyl dithiocarbamate and thiourea, which combine with the copper moiety in the enzyme, are generally potent inhibitors of PPO. The inhibitors are copper-chelating agents and they suppress browning activities in which copper is directly involved in the oxidation of phenolic compounds | Malpighia glabra | |
Sodium metabisulfite | evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate | Malpighia glabra | |
Thiourea | evaluated for effectiveness as an inhibitor of PPO activity, using catechol as the substrate. Inhibitors such as sodium diethyl dithiocarbamate and thiourea, which combine with the copper moiety in the enzyme, are generally potent inhibitors of PPO. The inhibitors are copper-chelating agents and they suppress browning activities in which copper is directly involved in the oxidation of phenolic compounds | Malpighia glabra |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.24 | - |
pyrogallol | - |
Malpighia glabra | |
3.6 | - |
caffeic acid | - |
Malpighia glabra | |
4.1 | - |
L-Dopa | - |
Malpighia glabra | |
5.2 | - |
catechol | - |
Malpighia glabra | |
6.9 | - |
4-methylcatechol | - |
Malpighia glabra |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
copper | inhibitors such as sodium diethyl dithiocarbamate and thiourea, which combine with the copper moiety in the enzyme, are generally potent inhibitors of PPO. The inhibitors are copper-chelating agents and they suppress browning activities in which copper is directly involved in the oxidation of phenolic compounds | Malpighia glabra |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
38000 | - |
1 * 52000 + 1 * 38000, the electrophoretic pattern of cherry PPO in SDS-PAGE reveals two dominant bands with molecular masses of 52 and 38 kDa | Malpighia glabra |
52000 | - |
1 * 52000 + 1 * 38000, the electrophoretic pattern of cherry PPO in SDS-PAGE reveals two dominant bands with molecular masses of 52 and 38 kDa | Malpighia glabra |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Malpighia glabra | - |
the Barbados cherry (Malpighia glabra L.) has a very short shelf life under ambient conditions due to skin colour loss and quality deterioration during storage | - |
Purification (Comment) | Organism |
---|---|
extracted and purified through ammonium sulfate precipitation, gel filtration, and affinity chromatography | Malpighia glabra |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
40192 U/mg, phenyl sepharose, purification profile of Barbados cherry PPO. One Unit of enzyme activity is defined as the amount of enzyme that caused an increase in absorbance of 0.001 min-1 | Malpighia glabra |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4-methylcatechol + 1/2 O2 | efficient diphenolic substrates for cherry PPO | Malpighia glabra | 4-methyl-1,2-benzoquinone + H2O | - |
? | |
caffeic acid + 1/2 O2 | - |
Malpighia glabra | caffeoyl quinone + H2O | - |
? | |
catechol + 1/2 O2 | efficient diphenolic substrates for cherry PPO | Malpighia glabra | 1,2-benzoquinone + H2O | - |
? | |
D-tyrosine + O2 + AH2 | - |
Malpighia glabra | L-3,4-dihydroxyphenylalanine + H2O + A | - |
? | |
ferulic acid + O2 + AH2 | - |
Malpighia glabra | (2E)-3-(3,4-dihydroxy-5-methoxyphenyl)prop-2-enoic acid + H2O + A | - |
? | |
L-dopa + 1/2 O2 | - |
Malpighia glabra | L-dopaquinone + H2O | - |
? | |
additional information | substrate-binding site of cherry PPO has a high affinity for small o-diphenols, such as catechol, 4-methylcatechol or L-dopa, and less affinity for the larger o-diphenols, caffeic acid, and triphenol-pyrogallol | Malpighia glabra | ? | - |
? | |
pyrogallol + 1/2 O2 | - |
Malpighia glabra | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
heterodimer | 1 * 52000 + 1 * 38000, the electrophoretic pattern of cherry PPO in SDS-PAGE reveals two dominant bands with molecular masses of 52 and 38 kDa | Malpighia glabra |
Synonyms | Comment | Organism |
---|---|---|
polyphenol oxidase | - |
Malpighia glabra |
PPO | - |
Malpighia glabra |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
24 | - |
optimum temperature of cherry PPO, with caffeic acid as substrate | Malpighia glabra |
25 | - |
optimum temperature of cherry PPO, with ferulic acid as substrate | Malpighia glabra |
30 | - |
optimum temperature of cherry PPO, with pyrogallol as substrate | Malpighia glabra |
36 | - |
optimum temperature of cherry PPO, with 4-methylcatechol as substrate | Malpighia glabra |
40 | - |
optimum temperature of cherry PPO, with catechol as substrate | Malpighia glabra |
41 | - |
optimum temperature of cherry PPO, with L-dopa as substrate | Malpighia glabra |
47 | - |
optimum temperature of cherry PPO, with D-tyrosine as substrate | Malpighia glabra |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
additional information | - |
enzyme is relatively stable at 60°C, with 55% loss of activity, unstable at temperatures above 75°C. The enzyme is incubated at different temperatures (45-85°C) for 30 min and, after cooling, the residual enzyme activity is measured | Malpighia glabra |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5.2 | - |
optimum pH of cherry PPO, with D-tyrosine as substrate | Malpighia glabra |
5.4 | - |
optimum pH of cherry PPO, with caffeic acid as substrate | Malpighia glabra |
5.6 | - |
optimum pH of cherry PPO, with ferulic acid as substrate | Malpighia glabra |
6.6 | - |
optimum pH of cherry PPO, with L-dopa as substrate | Malpighia glabra |
7 | - |
optimum pH of cherry PPO, with 4-methylcatechol as substrate | Malpighia glabra |
7 | - |
optimum pH of cherry PPO, with catechol as substrate | Malpighia glabra |
8 | - |
optimum pH of cherry PPO, with pyrogallol as substrate | Malpighia glabra |