נגישות
menu      
חיפוש מתקדם
תחביר
חפש...
הספר "אוצר וולקני"
אודות
תנאי שימוש
ניהול
קהילה:
אסיף מאגר המחקר החקלאי
פותח על ידי קלירמאש פתרונות בע"מ -
Effect of methimazole on the activity of mushroom tyrosinase
Year:
1986
Source of publication :
Biochemical Journal
Authors :
כהן, ורדה
;
.
Volume :
235
Co-Authors:
Andrawis, A., Department of Food Technology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
Kahn, V., Department of Food Technology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
Facilitators :
From page:
91
To page:
96
(
Total pages:
6
)
Abstract:
Methimazole (1-methyl-2-mercaptoimidazole) inhibits both the mono- and the o-dihydroxy-phenolase activities of mushroom tyrosinase when assayed spectrophotometrically. With DL-3,4-dihydroxyphenylalanine as substrate, the inhibition was found to be a mixed-type one with K(i) 4.6 x 10-6 M. We found that methimazole can interact with the oxidation products of o-dihydroxyphenols, probably with o-quinones, to form a conjugate. The conjugate formed between methimazole and o-benzoquinone was separated by chromatography on Sephadex G-10 and was characterized by an absorption maximum at 248-260 nm. Our data suggest that methimazole inhibits mushroom tyrosinase activity in two ways: (1) by conjugating with o-quinones, thereby causing an apparent inhibition in pigmented product formation as judged by the spectrophotometric assay; and (ii) by chelating copper at the active site of the enzyme, as judged by assaying the release of 3HHO from L-[3,5-3H]tyrosine.
Note:
Related Files :
Basidiomycota
Binding Sites
Catechols
Chromatography, Gel
Dihydroxyphenylalanine
enzyme inhibition
Quinones
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
24866
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:10
You may also be interested in
Scientific Publication
Effect of methimazole on the activity of mushroom tyrosinase
235
Andrawis, A., Department of Food Technology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
Kahn, V., Department of Food Technology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
Effect of methimazole on the activity of mushroom tyrosinase
Methimazole (1-methyl-2-mercaptoimidazole) inhibits both the mono- and the o-dihydroxy-phenolase activities of mushroom tyrosinase when assayed spectrophotometrically. With DL-3,4-dihydroxyphenylalanine as substrate, the inhibition was found to be a mixed-type one with K(i) 4.6 x 10-6 M. We found that methimazole can interact with the oxidation products of o-dihydroxyphenols, probably with o-quinones, to form a conjugate. The conjugate formed between methimazole and o-benzoquinone was separated by chromatography on Sephadex G-10 and was characterized by an absorption maximum at 248-260 nm. Our data suggest that methimazole inhibits mushroom tyrosinase activity in two ways: (1) by conjugating with o-quinones, thereby causing an apparent inhibition in pigmented product formation as judged by the spectrophotometric assay; and (ii) by chelating copper at the active site of the enzyme, as judged by assaying the release of 3HHO from L-[3,5-3H]tyrosine.
Scientific Publication
You may also be interested in