Abstract
Three substrate analogs of dopamine β-hydroxylase, viz. 2-X-3-(p-hydroxyphenyl)-1-propenes (where X = Br, Cl, H), have been synthesized, and all behave as substrates requiring O2 and ascorbate for the enzyme-catalyzed hydroxylation reaction. The products have been characterized by mass spectrometry as the respective 2-X-3-hydroxy-3-(p-hydroxyphenyl)-1-propenes. The relative k(cat) values for these compounds at pH 5.5, 0.25 mM O2 are 49 min-1 (2-H), 8.6 min-1 (2-Cl), and 7.0 min-1 (2-Br). All three compounds have the characteristics of mechanism-based inhibitors of dopamine β-hydroxylase since incubation of enzyme with these compounds under turnover conditions leads to a time-dependent loss of activity. The k(inact) values at pH 5.5, 0.25 mM O2 are 0.08, 0.20, and 0.51 min-1, respectively, for the 2-Br-, 2-Cl-, and 2-H-substituted analogs. No reactivation was observed after exhaustive dialysis of enzyme inactivated by 2-Br-3-(p-hydroxyphenyl)-1-propene, suggesting irreversible inactivation of dopamine β-hydroxylase.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6925-6930 |
| Number of pages | 6 |
| Journal | Journal of Biological Chemistry |
| Volume | 259 |
| Issue number | 11 |
| State | Published - 1984 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Synthesis of several 2-substituted 3-(p-hydroxyphenyl)-1-propenes and their characterization as mechanism-based inhibitors of dopamine β-hydroxylase. / Rajashekhar, B.; Fitzpatrick, Paul F; Colombo, G.; Villafranca, J. J.
In: Journal of Biological Chemistry, Vol. 259, No. 11, 1984, p. 6925-6930.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis of several 2-substituted 3-(p-hydroxyphenyl)-1-propenes and their characterization as mechanism-based inhibitors of dopamine β-hydroxylase
AU - Rajashekhar, B.
AU - Fitzpatrick, Paul F
AU - Colombo, G.
AU - Villafranca, J. J.
PY - 1984
Y1 - 1984
N2 - Three substrate analogs of dopamine β-hydroxylase, viz. 2-X-3-(p-hydroxyphenyl)-1-propenes (where X = Br, Cl, H), have been synthesized, and all behave as substrates requiring O2 and ascorbate for the enzyme-catalyzed hydroxylation reaction. The products have been characterized by mass spectrometry as the respective 2-X-3-hydroxy-3-(p-hydroxyphenyl)-1-propenes. The relative k(cat) values for these compounds at pH 5.5, 0.25 mM O2 are 49 min-1 (2-H), 8.6 min-1 (2-Cl), and 7.0 min-1 (2-Br). All three compounds have the characteristics of mechanism-based inhibitors of dopamine β-hydroxylase since incubation of enzyme with these compounds under turnover conditions leads to a time-dependent loss of activity. The k(inact) values at pH 5.5, 0.25 mM O2 are 0.08, 0.20, and 0.51 min-1, respectively, for the 2-Br-, 2-Cl-, and 2-H-substituted analogs. No reactivation was observed after exhaustive dialysis of enzyme inactivated by 2-Br-3-(p-hydroxyphenyl)-1-propene, suggesting irreversible inactivation of dopamine β-hydroxylase.
AB - Three substrate analogs of dopamine β-hydroxylase, viz. 2-X-3-(p-hydroxyphenyl)-1-propenes (where X = Br, Cl, H), have been synthesized, and all behave as substrates requiring O2 and ascorbate for the enzyme-catalyzed hydroxylation reaction. The products have been characterized by mass spectrometry as the respective 2-X-3-hydroxy-3-(p-hydroxyphenyl)-1-propenes. The relative k(cat) values for these compounds at pH 5.5, 0.25 mM O2 are 49 min-1 (2-H), 8.6 min-1 (2-Cl), and 7.0 min-1 (2-Br). All three compounds have the characteristics of mechanism-based inhibitors of dopamine β-hydroxylase since incubation of enzyme with these compounds under turnover conditions leads to a time-dependent loss of activity. The k(inact) values at pH 5.5, 0.25 mM O2 are 0.08, 0.20, and 0.51 min-1, respectively, for the 2-Br-, 2-Cl-, and 2-H-substituted analogs. No reactivation was observed after exhaustive dialysis of enzyme inactivated by 2-Br-3-(p-hydroxyphenyl)-1-propene, suggesting irreversible inactivation of dopamine β-hydroxylase.
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UR - http://www.scopus.com/inward/citedby.url?scp=0021149768&partnerID=8YFLogxK
M3 - Article
C2 - 6547138
AN - SCOPUS:0021149768
VL - 259
SP - 6925
EP - 6930
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 11
ER -