Ectoine hydroxylase displays selective trans-3-hydroxylation activity towards l-proline

2019 ◽  
Vol 103 (14) ◽  
pp. 5689-5698 ◽  
Author(s):  
Ryotaro Hara ◽  
Takeyuki Nishikawa ◽  
Takuya Okuhara ◽  
Kento Koketsu ◽  
Kuniki Kino
Keyword(s):  
Hydroxylation Activity

Assay for Tyrosine Hydroxylation Activity of Tyrosinase from Betalain-Forming Plants and Cell Cultures

1996 ◽  
Vol 238 (1) ◽  
pp. 72-75 ◽  
Author(s):  
Ulrike Steiner ◽  
Willibald Schliemann ◽  
Dieter Strack
Keyword(s):  
Cell Cultures ◽  
Tyrosine Hydroxylation ◽  
Hydroxylation Activity

(+)-Bufuralol 1′-hydroxylation activity in human and rhesus monkey intestine and liver

1995 ◽  
Vol 50 (9) ◽  
pp. 1521-1525 ◽  
Author(s):  
Thomayant Prueksaritanont ◽  
Lynn M. Dwyer ◽  
Alastair E. Cribb
Keyword(s):  
Rhesus Monkey ◽  
Hydroxylation Activity

Cryptochrome 2 is involved in betacyanin decomposition induced by blue light in Suaeda salsa

2006 ◽  
Vol 33 (7) ◽  
pp. 697 ◽  
Author(s):  
Wang Chang-Quan ◽  
Liu Tao
Keyword(s):  
Western Blot ◽  
Blue Light ◽  
Hypocotyl Elongation ◽  
Suaeda Salsa ◽  
Biosynthesis Pathway ◽  
Tyrosine Hydroxylation ◽  
Key Enzyme ◽  
Cryptochrome 2 ◽  
Hydroxylation Activity

Seeds of the halophyte Suaeda salsa (L.) Pall. were cultured in 24 h dark and 14 h blue light / 10 h dark to examine the role of blue light and the blue-light-absorbing photoreceptor cryptochrome 2 (CRY2) in betacyanin accumulation, hypocotyl elongation and cotyledon opening in S. salsa seedlings. Darkness significantly promoted betacyanin accumulation and hypocotyl elongation but inhibited cotyledon opening. Blue light suppressed betacyanin accumulation and hypocotyl elongation but stimulated cotyledon opening. Betacyanin in S. salsa seedlings decomposed with time in blue light. Western blot analysis showed that CRY2 protein accumulated both in hypocotyls and cotyledons of S. salsa seedlings grown in dark, but degraded with time in blue light, which was paralleled by a decrease of tyrosine hydroxylation activity of tyrosinase, a key enzyme involved in the betalain biosynthesis pathway. These results suggest that CRY2 protein mediates betacyanin decomposition via inactivation of tyrosinase in S. salsa seedlings, and the blue-light-dependent degradation of CRY2 protein is crucial to its function.

Functional Characterization of Wild-type and 49 CYP2D6 Allelic Variants for N-Desmethyltamoxifen 4-Hydroxylation Activity

2014 ◽  
Vol 29 (5) ◽  
pp. 360-366 ◽  
Author(s):  
Yuka Muroi ◽  
Takahiro Saito ◽  
Masamitsu Takahashi ◽  
Kanako Sakuyama ◽  
Yui Niinuma ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Wild Type ◽  
Allelic Variants ◽  
Hydroxylation Activity

scholarly journals Ring-and N-hydroxylation of 2-acetamidofluorene by rat liver reconstituted cytochrome P-450 enzyme system

1975 ◽  
Vol 150 (3) ◽  
pp. 561-564 ◽  
Author(s):  
P D Lotlikar ◽  
K Zaleski
Keyword(s):  
Cytochrome C ◽  
Rat Liver ◽  
Enzyme System ◽  
Partial Purification ◽  
Hydroxylated Metabolites ◽  
Triton X ◽  
Cytochrome P 450 ◽  
Ring Hydroxylation ◽  
Hydroxylation Activity ◽  
Nadph Cytochrome C Reductase

The N- and ring-hydroxylation of 2-acetamidofluorene were studied with a reconstituted cytochrome P-450 enzyme from microsomal fractions of liver from both control and 3-methylcholanthrene-pretreated rats. Proteinase treatment and Triton X-100 solubilization were two important steps for partial purification of the cytochrome P-450 fraction. Both cytochrome P-450 and NADPH-cytochrome c reductase fractions were required for optimum N- and ring-hydroxylation activity. Hydroxylation activity was determined by the source of cytochrome P-450 fraction; cytochrome P-450 fraction from pretreated animals was severalfold more active than the fraction from controls. Formation of N-hydroxylated metabolites with reconstituted systems from both control and pretreated animals was greater than that with their respective whole microsomal fractions.

Evaluation of the effects of hydrophilic organic solvents on CYP3A-mediated drug-drug interaction in vitro

2006 ◽  
Vol 25 (12) ◽  
pp. 715-721 ◽  
Author(s):  
M Iwase ◽  
N Kurata ◽  
R Ehana ◽  
Y Nishimura ◽  
T Masamoto ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Human Liver ◽  
Liver Microsomes ◽  
Dependent Manner ◽  
Cyp3a4 Activity ◽  
Modulation Effect ◽  
Concentration Dependent Manner ◽  
Hydroxylation Activity

This study evaluated the effects of the commonly used hydrophilic organic solvents, acetonitrile, methanol, ethanol, 1-propanol, dimethyl sulfoxide (DMSO), N,N-dimethylformamide, polyethylene glycol and propylene glycol, on CYP3A in pooled human liver microsomes, using testosterone and midazolam as substrates. Furthermore, we examined the modulation effect of organic solvents on CYP3A inhibition by ketoconazole. Testosterone 6b-hydroxylation activity was potently inhibited in the presence of DMSO and 1-propanol in a concentration-dependent manner. Midazolam 1'-hydroxylation activity, however, was weakly inhibited only by 1% of DMSO, the highest concentration used in this study. Moreover, the potency of ketoconazole to inhibit CYP3A activities was variable, depending on the organic solvent used as a dissolving solvent for ketoconazole. Our data indicate that each organic solvent had an effect on CYP3A4 activity, evaluated by both substrates with different magnitudes. Furthermore, it was shown that the effects of organic solvents on CYP3A activity are substrate-dependent. The present study also shows that methanol had little effect on either substrate.

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