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Reflections on sterol sidechain cleavage process catalyzed by cytochrome P450(scc)
1Department of Obstetrics and Gynecology, Institute for Health Sciences, St. Luke's-Roosevelt Hospital Center, 432W 58th Street, New York, NY 10019, USA. sizz@columbia.edu
The Journal of Steroid Biochemistry and Molecular Biology
|September 1, 2001
Summary
The established mechanism for cholesterol side-chain cleavage by cytochrome P450(scc) is challenged. Evidence suggests a different pathway, proposing two new hypotheses for this crucial biological process.
Area of Science:
- Biochemistry
- Enzymology
- Steroid Metabolism
Background:
- Cholesterol side-chain cleavage is a critical step in steroid hormone biosynthesis.
- The enzyme cytochrome P450(scc) catalyzes this conversion.
- The currently accepted mechanism involves sequential hydroxylations followed by cleavage.
Purpose of the Study:
- To critically evaluate the evidence supporting the traditional mechanism of cholesterol side-chain cleavage.
- To investigate alternative pathways for the cytochrome P450(scc)-catalyzed reaction.
Main Methods:
- Literature review and critical analysis of existing experimental data.
- Theoretical examination of biochemical reaction mechanisms.
Main Results:
- The evidence for the traditional two-hydroxylation, one-cleavage mechanism is insufficient.
- The accepted model does not fully explain the observed biochemical data.
Conclusions:
- The traditional mechanism for cholesterol side-chain cleavage is likely incorrect.
- Two novel mechanistic hypotheses are proposed for further investigation.
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