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

BRENDA support

Literature summary for 1.14.18.1 extracted from

  • Saeidian, S.; Keyhani, E.; Keyhani, J.
    Effect of ionic detergents, nonionic detergents, and chaotropic agents on polyphenol oxidase activity from dormant saffron (Crocus sativus L.) corms (2007), J. Agric. Food Chem., 55, 3713-3719.
    View publication on PubMed
Search for more literature for 1.14.18.1

Activating Compound

Activating Compound Comment Organism Structure
Sarkosyl SDS and sarkosyl activate the cresolase activity, while only SDS activates the catecholase activity. The addition of up to 0.25 mM sarkosyl to the reaction mixture resulted in up to a 30% increase in the activity when p-cresol is used as the substrate Crocus sativus
SDS SDS and sarkosyl activate the cresolase activity, while only SDS activates the catecholase activity. The extent of stimulation depends on the concentration of detergent and reaches a maximum at 0.16 mM SDS Crocus sativus

Inhibitors

Inhibitors Comment Organism Structure
guanidine hydrochloride up to 30% inhibition of the cresolase activity is observed upon addition of up to 10 mM guanidine hydrochloride, the inhibition remained at the same level in up to 16 mM guanidine hydrochloride. On the other hand, up to 55% inhibition of the catecholase activity is observed in 17 mM guanidine hydrochloride, a further increase in guanidine hydrochloride to 90 mM led to as much as 75% inhibition of the catecholase activity Crocus sativus
additional information over the same ranges of concentrations (0-30 microM for Triton X-100, 0-65 microM for Tween 20 and for Tween 80, and 0-83 microM for NP-40), no effect is observed on PPO activity when catechol is used as the substrate Crocus sativus
NP-40 leads to a decrease in the PPO activity, whether p-cresol or catechol is used as the substrate. 50% inhibition is observed in the presence of 68 microM NP-40 Crocus sativus
sodium cholate in the presence of sodium cholate a decrease in PPO activity is observed when p-cresol is used as the substrate. The inhibition increases with increasing detergent concentration, until a plateau is reached. PPO activity is reduced to 50% of the control Crocus sativus
sodium deoxycholate in the presence of sodium deoxycholate, a decrease in PPO activity is observed when p-cresol is used as the substrate. The inhibition increases with increasing detergent concentration, until a plateau is reached. PPO activity is reduced to 50% of the control Crocus sativus
Triton X-100 leads to a decrease in the PPO activity, whether p-cresol or catechol is used as the substrate. With p-cresol as the substrate, up to 80% inhibition is observed in the presence of 30 microM Triton X-100 Crocus sativus
Tween 20 leads to a decrease in the PPO activity, whether p-cresol or catechol is used as the substrate. 50% inhibition is observed in the presence of 40-65 microM Tween 20 Crocus sativus
Tween 80 leads to a decrease in the PPO activity, whether p-cresol or catechol is used as the substrate. 60% inhibition is observed in the presence of 32-60 microM Tween 80 Crocus sativus
Urea 30% inhibition of cresolase activity is reached with 17 mM urea. No further inhibition is observed for up to 100 mM urea. When the catecholase activity is assayed in the presence of urea, up to 60% inhibition is observed in 0.5 mM urea, a further increase in urea concentration resulted in more inhibition Crocus sativus

Organism

Organism UniProt Comment Textmining
Crocus sativus
-
-
-

Purification (Commentary)

Purification (Comment) Organism
partially purified Crocus sativus

Reaction

Reaction Comment Organism Reaction ID
L-tyrosine + O2 = dopaquinone + H2O catalyzes the hydroxylation of monophenols to o-diphenols (cresolase activity) and the oxidation of o-diphenols to o-quinones (catecholase activity) Crocus sativus
a

Source Tissue

Source Tissue Comment Organism Textmining
corm
-
 Crocus sativus
-

Storage Stability

Storage Stability Organism
catecholase activity is only detectable on freshly collected fractions and is rapidly lost upon storage, whether at 4 or -20°C. Crocus sativus

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
4-methylcatechol + 1/2 O2
-
 Crocus sativus 4-methyl-1,2-benzoquinone + H2O
-
 ?
catechol + 1/2 O2
-
 Crocus sativus 1,2 benzoquinone + H2O
-
 ?
p-cresol + O2 + AH2
-
 Crocus sativus 4-methylcatechol + H2O + A
-
 ?

Synonyms

Synonyms Comment Organism
polyphenol oxidase
-
 Crocus sativus
PPO
-
 Crocus sativus

Temperature Range [°C]

Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
22 25 assays are conducted at room temperature Crocus sativus

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
6.7
-
-
 Crocus sativus