GO:0008390 testosterone 16-alpha-hydroxylase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008390 (testosterone 16-alpha-hydroxylase activity) is a molecular_function term describing the cytochrome P450-dependent conversion of testosterone to 16alpha,17beta-dihydroxyandrost-4-en-3-one.
• The reaction consumes O2 and reduced NADPH--hemoprotein reductase and releases H+, H2O and oxidized NADPH--hemoprotein reductase.
• Mouse liver testosterone 16-alpha-hydroxylase was purified and characterized as a phenobarbital-inducible P450 with strict regio- and stereospecificity.
• Expression of this activity is female-predominant in mouse liver and is repressed in the strain 129/J background.
• Related 16-alpha-hydroxylase activities act on progesterone and estrogens, linking this chemistry to steroid hormone metabolism in humans.
• Elevated estrogen 16-alpha-hydroxylase activity has been discussed as a possible biomarker in human breast cancer risk.
Description
GO:0008390, testosterone 16-alpha-hydroxylase activity, is a molecular_function term in the Gene Ontology that describes the catalytic conversion of testosterone into 16alpha,17beta-dihydroxyandrost-4-en-3-one. This reaction is carried out by cytochrome P450 enzymes and requires molecular oxygen together with reduced NADPH--hemoprotein reductase as the electron donor. The term is therefore central to understanding how steroid hormones are oxidatively modified at the 16-alpha position, a modification that changes the biological behavior of androgens and related steroids. Historically, the activity was defined biochemically in mouse liver, where a phenobarbital-inducible P450 fraction was purified and shown to hydroxylate testosterone with high regioselectivity and stereospecificity. Subsequent work demonstrated that this activity is expressed in a female-predominant manner and can be repressed in certain mouse strains, indicating that it is under developmental and genetic control. Because the same 16-alpha-hydroxylase chemistry also acts on progesterone and estrogens, the term intersects with broader steroidogenic pathways relevant to endocrinology and oncology. For researchers, GO:0008390 provides a precise annotation target when assigning function to cytochrome P450 genes, interpreting steroid metabolite profiles, or designing experiments that test whether a candidate enzyme contributes to 16-alpha-hydroxylation. It is also a useful anchor for comparative studies of human and rodent steroid metabolism, since related human activities have been linked to breast and endometrial cancer biology.
testosterone 16-alpha-hydroxylase activity At A Glance
| GO ID | GO:0008390 |
|---|---|
| GO term | testosterone 16-alpha-hydroxylase activity |
| Ontology | molecular_function |
| Definition | Catalysis of the reaction: O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 16alpha,17beta-dihydroxyandrost-4-en-3-one + H+ + H2O + oxidized [NADPH--hemoprotein reductase] |
| Synonym | cytochrome P450 CYP2B10; cytochrome P450 CYP2B9; cytochrome P450 CYP2D10; cytochrome P450 CYP2D11; cytochrome P450 CYP2D9 |
| Major function | Oxidative hydroxylation of testosterone at the 16-alpha position by cytochrome P450 enzymes |
| Cofactor requirement | Molecular oxygen and reduced NADPH--hemoprotein reductase |
| Substrate | Testosterone; related 16-alpha-hydroxylase activities also act on progesterone and estrogens |
| Representative enzyme | Mouse liver testosterone 16-alpha-hydroxylase (P450(16)alpha), phenobarbital-inducible |
| Expression pattern | Female-predominant in mouse liver; repressed in strain 129/J |
What Is GO:0008390?
In plain terms, GO:0008390 describes the enzyme activity that adds a hydroxyl group to the 16-alpha position of testosterone. According to the QuickGO definition, it catalyzes the reaction O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 16alpha,17beta-dihydroxyandrost-4-en-3-one + H+ + H2O + oxidized [NADPH--hemoprotein reductase]. This is a cytochrome P450-type monooxygenation reaction in which one atom of molecular oxygen is incorporated into the steroid substrate while the other is reduced to water, with electrons supplied by NADPH via a hemoprotein reductase. The term is a molecular_function annotation and is associated with synonyms including cytochrome P450 CYP2B10, CYP2B9, CYP2D10, CYP2D11 and CYP2D9.
Why Is testosterone 16-alpha-hydroxylase activity Important in Cell Biology?
GO:0008390 matters because 16-alpha-hydroxylation is a committed oxidative modification that changes the chemical identity and downstream behavior of testosterone and related steroids. The activity is a classic example of cytochrome P450 regio- and stereospecificity, making it a model for studying how P450 enzymes select a single position on a complex steroid scaffold. Because the same chemistry acts on progesterone and estrogens, the term connects androgen metabolism to broader endocrine pathways that have been implicated in hormone-dependent cancers. In addition, the female-predominant and strain-specific regulation of the mouse enzyme illustrates how steroid hydroxylase activity can be controlled by genetic background and hormonal status. For translational researchers, measuring 16-alpha-hydroxylase activity can inform studies of steroid hormone disposition and may serve as a biomarker context in breast cancer risk research.
• Defines a specific cytochrome P450 monooxygenation reaction that converts testosterone to 16alpha,17beta-dihydroxyandrost-4-en-3-one.
• Provides a biochemical marker for phenobarbital-inducible P450 enzymes in mouse liver.
• Illustrates strict regio- and stereospecificity of steroid hydroxylation by P450 enzymes.
• Connects androgen metabolism to progesterone and estrogen 16-alpha-hydroxylation pathways.
• Shows female-predominant expression and strain-dependent repression, linking activity to genetic background.
• Has been discussed in the context of estrogen 16-alpha-hydroxylase activity and breast cancer risk biomarkers.
• Supports comparative endocrinology studies between rodent models and human steroid metabolism.
• Offers a functional annotation target for cytochrome P450 genes with overlapping substrate specificity.
• Helps interpret steroid metabolite profiles in endocrine and oncology research.
• Guides design of enzyme assays that distinguish 16-alpha-hydroxylation from other testosterone oxidations.
Molecular Mechanism of testosterone 16-alpha-hydroxylase activity
Substrate binding and steroid recognition
In simple terms: The enzyme first grabs testosterone and holds it in a precise orientation.
Testosterone 16-alpha-hydroxylase activity depends on the cytochrome P450 active site binding testosterone in an orientation that exposes the 16-alpha position to the catalytic center. Purification of the mouse liver enzyme showed that this binding is highly selective, because the enzyme hydroxylates testosterone with strict regioselectivity and stereospecificity rather than producing a mixture of products. This substrate recognition step is the basis for the term's specificity within the broader family of steroid hydroxylases.
Electron transfer from NADPH--hemoprotein reductase
In simple terms: A partner protein delivers electrons so the enzyme can activate oxygen.
The QuickGO definition specifies reduced [NADPH--hemoprotein reductase] as a required reactant, meaning the P450 enzyme must receive electrons from a reductase partner to carry out catalysis. In the overall reaction, O2 is consumed and the reductase is oxidized, while the steroid substrate gains a hydroxyl group at C16 and water and H+ are released. This electron-transfer requirement is a defining feature of cytochrome P450 monooxygenation and distinguishes the activity from simple hydrolytic or dehydrogenation reactions.
Oxygen activation and hydroxylation chemistry
In simple terms: Oxygen is split, and one oxygen atom is inserted into testosterone.
After substrate binding and electron delivery, the P450 heme activates molecular oxygen so that one oxygen atom is inserted into testosterone at the 16-alpha position, generating 16alpha,17beta-dihydroxyandrost-4-en-3-one. The second oxygen atom is reduced to water, and a proton is released as part of the balanced reaction given in the QuickGO definition. The stereochemical outcome is tightly controlled, as shown by the stereospecific characterization of the purified mouse enzyme.
Regulation by induction and genetic background
In simple terms: The amount of active enzyme can go up or down depending on drugs and mouse strain.
Testosterone 16-alpha-hydroxylase activity in mouse liver is inducible by phenobarbital, which increases the level of the responsible P450 protein. The activity is also female-predominant and can be repressed in the strain 129/J background, demonstrating that expression is not constitutive but is modulated by hormonal and genetic factors. These observations indicate that the catalytic capacity for 16-alpha-hydroxylation is controlled at the level of enzyme expression as well as intrinsic catalytic specificity.
Overlap with related 16-alpha-hydroxylase activities
In simple terms: Similar enzymes can perform the same chemistry on other steroids.
The 16-alpha-hydroxylase chemistry described by GO:0008390 is related to activities that act on progesterone and estrogens, including human cytochrome P450 17 alpha-hydroxylase acting as a progesterone 16 alpha-hydroxylase. Estrogen 16 alpha-hydroxylase activity has been detected in human fetal tissues and in women with breast and endometrial cancer. This overlap means that annotation of GO:0008390 should be interpreted alongside related steroid 16-alpha-hydroxylation reactions when assigning function to specific P450 genes.
Key Genes Involved in GO:0008390 testosterone 16-alpha-hydroxylase activity
The genes and proteins most directly associated with testosterone 16-alpha-hydroxylase activity are cytochrome P450 enzymes and their electron-transfer partners, with additional relevance from related steroid 16-alpha-hydroxylases.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CYP2B10 | Cytochrome P450 synonym associated with GO:0008390 | Mouse P450 involved in phenobarbital-inducible steroid hydroxylation |
| CYP2B9 | Cytochrome P450 synonym associated with GO:0008390 | Related mouse P450 with steroid hydroxylase activity |
| CYP2D10 | Cytochrome P450 synonym associated with GO:0008390 | P450 family member annotated to testosterone 16-alpha-hydroxylase activity |
| CYP2D11 | Cytochrome P450 synonym associated with GO:0008390 | P450 family member annotated to testosterone 16-alpha-hydroxylase activity |
| CYP2D9 | Cytochrome P450 synonym associated with GO:0008390 | P450 family member annotated to testosterone 16-alpha-hydroxylase activity |
| P450(16)alpha | Purified mouse liver testosterone 16-alpha-hydroxylase | Biochemical reference enzyme for regio- and stereospecificity |
| I-P-450(16)alpha | Phenobarbital-inducible mouse testosterone 16-alpha-hydroxylase | Model for induction studies |
| NADPH--hemoprotein reductase | Electron donor for the P450 reaction | Required reactant in the GO definition |
| CYP17A1 | Human P450 with progesterone 16 alpha-hydroxylase activity | Links 16-alpha-hydroxylation to human steroidogenesis |
| CYP2C9 | Human P450 with hydroxylation activity | Context for P450 genotype-phenotype studies |
| CYP2C19 | Human P450 with hydroxylation activity | Context for P450 genotype-phenotype studies |
| Estrogen 16 alpha-hydroxylase | Activity acting on estrogens | Relevant to breast and endometrial cancer research |
| Fetal tissue 16 alpha-hydroxylase | Activity detected in human fetal tissues | Developmental steroid metabolism context |
| Testosterone | Substrate of GO:0008390 | Central steroid substrate for the reaction |
| 16alpha,17beta-dihydroxyandrost-4-en-3-one | Product of GO:0008390 | Metabolite marker for 16-alpha-hydroxylation |
| Phenobarbital | Inducer of mouse testosterone 16-alpha-hydroxylase | Experimental tool for induction studies |
| Strain 129/J background | Genetic context that represses the activity | Model for strain-dependent regulation |
How Is testosterone 16-alpha-hydroxylase activity Regulated?
Testosterone 16-alpha-hydroxylase activity is regulated at the level of enzyme expression and by genetic background. In mouse liver, the activity is induced by phenobarbital, which increases the amount of the responsible P450 protein. The activity is female-predominant and is repressed in the strain 129/J background, showing that hormonal and strain-specific factors modulate expression. Because the reaction requires reduced NADPH--hemoprotein reductase, the availability of this electron-transfer partner also constrains catalytic flux. Related human P450 enzymes such as CYP2C9 and CYP2C19 show genotype-dependent hydroxylation activities, illustrating that P450-mediated steroid and drug hydroxylation can vary with inherited polymorphisms.
testosterone 16-alpha-hydroxylase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Estrogen 16 alpha-hydroxylase | Breast cancer risk biomarker | Cell-based steroid hydroxylase assay with estrogen substrates |
| Estrogen 16 alpha-hydroxylase | Breast and endometrial cancer | Patient-derived steroid metabolite profiling |
| CYP17A1 | Human steroidogenesis and progesterone 16 alpha-hydroxylation | Recombinant P450 expression in mammalian cells |
| CYP2C9 / CYP2C19 | Pharmacogenetic variation in hydroxylation | Genotype-stratified enzyme activity assays |
| Fetal tissue 16 alpha-hydroxylase | Developmental steroid metabolism | Human fetal tissue-derived microsomal assays |
Breast cancer risk and estrogen 16-alpha-hydroxylation
Elevated estrogen 16 alpha-hydroxylase activity has been discussed as a potential genotoxic or nongenotoxic biomarker in human breast cancer risk. Increased estrogen-16 alpha-hydroxylase activity has been reported in women with breast and endometrial cancer, suggesting that altered 16-alpha-hydroxylation of estrogens may accompany hormone-dependent tumor biology. Although these studies focus on estrogen substrates rather than testosterone, they establish the clinical context in which 16-alpha-hydroxylase chemistry is evaluated as a biomarker.
Endometrial cancer and steroid hormone metabolism
Women with breast and endometrial cancer have shown increased estrogen-16 alpha-hydroxylase activity, linking this enzymatic chemistry to hormone-responsive gynecologic malignancies. Because the same 16-alpha-hydroxylase concept applies to testosterone through GO:0008390, altered androgen hydroxylation may also be relevant to endocrine tumor research. These observations support the use of steroid hydroxylase activity measurements in studies of hormone-dependent cancer.
Human steroidogenesis and P450 17 alpha-hydroxylase
Human cytochrome P450 17 alpha-hydroxylase can catalyze progesterone 16 alpha-hydroxylase activity, demonstrating that human P450 enzymes participate in 16-alpha-hydroxylation chemistry. Estrogen 16 alpha-hydroxylase activity has been detected in human fetal tissues, indicating that this activity is present during development. Together, these findings connect GO:0008390-related chemistry to human endocrine physiology and developmental steroid metabolism.
Pharmacogenetic variation in P450 hydroxylation
Genotypes of CYP2C9 and CYP2C19 have been related to tolbutamide methyl hydroxylation and S-mephenytoin 4'-hydroxylation activities in Japanese and Caucasian populations. This pharmacogenetic context is relevant because P450 enzymes that perform 16-alpha-hydroxylation belong to the same superfamily and can show substrate overlap and population-specific activity differences. Such variation should be considered when interpreting steroid hydroxylase phenotypes in different cohorts.
From testosterone 16-alpha-hydroxylase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a candidate P450 gene carry testosterone 16-alpha-hydroxylase activity? | CRISPR knockout of the candidate gene followed by steroid hydroxylase assay |
| Which residue controls 16-alpha regio- and stereospecificity? | Point-mutation knock-in of the P450 active site |
| Can a human P450 substitute for the mouse enzyme in steroid hydroxylation? | Knock-in of human P450 cDNA into a mouse P450 locus |
| Where is the enzyme expressed in liver tissue? | Tagged knock-in with an epitope or fluorescent tag |
| Does overexpression change testosterone metabolite flux? | Overexpression of the P450 in a steroidogenic cell line |
| Is the activity inducible by phenobarbital? | Wild-type versus knockout mouse liver microsomes treated with phenobarbital |
How to Study the testosterone 16-alpha-hydroxylase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Microsomal steroid hydroxylase assay | Conversion of testosterone to 16alpha,17beta-dihydroxyandrost-4-en-3-one | Functional annotation of P450 enzymes |
| Recombinant P450 expression assay | Activity of a single P450 enzyme with testosterone | Assigning GO:0008390 to a candidate gene |
| Immunochemical detection | Protein level of the responsible P450 | Confirming induction and expression patterns |
| RNA-seq | Transcript levels of P450 genes | Linking expression to activity changes |
| Genotyping of P450 polymorphisms | Inherited variants in CYP2C9 and CYP2C19 | Pharmacogenetic correlation with hydroxylation activity |
| Steroid metabolite profiling | Downstream steroid products in biological samples | Biomarker studies in cancer cohorts |
| Fetal tissue enzyme assay | 16-alpha-hydroxylase activity in human fetal samples | Developmental steroid metabolism research |
| Progesterone 16-alpha-hydroxylase assay | Overlapping 16-alpha-hydroxylase activity | Distinguishing related P450 activities |
Enzyme activity assays with steroid substrates
The most direct way to study GO:0008390 is to incubate testosterone with a microsomal or recombinant P450 preparation in the presence of an NADPH-regenerating system and then quantify the formation of 16alpha,17beta-dihydroxyandrost-4-en-3-one. Purification and characterization of the mouse liver enzyme established the regio- and stereospecificity of this assay, making it the reference method for the activity. Related assays using progesterone or estrogen substrates can distinguish overlapping 16-alpha-hydroxylase activities.
Expression analysis by RNA and protein methods
Because the activity is regulated at the level of enzyme expression, RNA-seq and immunochemical detection of the responsible P450 protein are useful companion methods. The female-predominant expression pattern and repression in strain 129/J were demonstrated using biochemical and immunochemical characterization, which can be adapted to modern transcriptomic and proteomic workflows. Comparing transcript and activity levels helps determine whether changes in 16-alpha-hydroxylation are driven by expression or by intrinsic catalytic differences.
Genetic and pharmacogenetic association studies
Genotyping P450 enzymes such as CYP2C9 and CYP2C19 and correlating genotypes with hydroxylation activities provides a framework for studying inherited variation in P450-mediated metabolism. This approach can be extended to candidate genes annotated to GO:0008390 to test whether polymorphisms affect testosterone 16-alpha-hydroxylation. Population-specific differences observed in Japanese and Caucasian cohorts highlight the importance of ancestry-matched controls in such studies.
Biomarker studies in human cohorts
Estrogen 16 alpha-hydroxylase activity has been measured in human fetal tissues and in women with breast and endometrial cancer, illustrating how 16-alpha-hydroxylase chemistry can be evaluated as a biomarker. Elevated estrogen 16 alpha-hydroxylase activity has been discussed as a potential genotoxic or nongenotoxic biomarker in breast cancer risk, providing a template for cohort-based studies. These approaches can be adapted to testosterone 16-alpha-hydroxylase activity when appropriate steroid substrates and clinical samples are available.
How CRISPR Can Be Used to Study GO:0008390 testosterone 16-alpha-hydroxylase activity
Knockout
CRISPR knockout of a candidate P450 gene is used to test whether loss of the gene reduces testosterone 16-alpha-hydroxylase activity in liver-derived or steroidogenic cells. Because the mouse enzyme is inducible and female-predominant, knockout models should be compared with wild-type controls under matched hormonal and induction conditions. A reduction in 16alpha,17beta-dihydroxyandrost-4-en-3-one formation in knockout cells provides causal evidence that the gene contributes to GO:0008390.
Point Mutation
Point-mutation knock-in can be used to alter active-site residues of the P450 enzyme and test their contribution to regio- and stereospecificity. Because the purified mouse enzyme shows strict stereospecificity, targeted mutations that change the product ratio can reveal which residues control 16-alpha hydroxylation. Such models are valuable for distinguishing GO:0008390 from related steroid hydroxylase activities.
Knock-in
Knock-in of a human P450 cDNA into a mouse P450 locus can test whether a human enzyme can substitute for the mouse activity in vivo. This approach is useful when comparing human progesterone 16 alpha-hydroxylase activity with rodent testosterone 16-alpha-hydroxylase activity. Knock-in models also allow expression of tagged enzymes for localization and interaction studies.
Overexpression
Overexpression of a candidate P450 in a steroidogenic or hepatic cell line can increase flux through the 16-alpha-hydroxylation pathway and make product detection easier. Overexpression models are particularly useful when endogenous activity is low or when testing whether a P450 can use testosterone as a substrate. Combining overexpression with metabolite profiling can reveal downstream effects on steroid hormone balance.
How EDITGENE Supports testosterone 16-alpha-hydroxylase activity Research
Researchers studying testosterone 16-alpha-hydroxylase activity-related genes often need to determine whether a candidate gene is causally involved in the 16-alpha-hydroxylation of testosterone or whether its annotation reflects a related but distinct steroid hydroxylase activity. This requires precise genetic models that can remove, modify, or add P450 function in a controlled cellular background.
Contact EDITGENE today to design your custom CRISPR model for testosterone 16-alpha-hydroxylase activity research.
Frequently Asked Questions About testosterone 16-alpha-hydroxylase activity
What is testosterone 16-alpha-hydroxylase activity?
It is the cytochrome P450-dependent enzyme activity defined by GO:0008390 that converts testosterone to 16alpha,17beta-dihydroxyandrost-4-en-3-one using O2 and reduced NADPH--hemoprotein reductase.
What is the GO ID for testosterone 16-alpha-hydroxylase activity?
The Gene Ontology ID is GO:0008390, a molecular_function term.
What reaction does GO:0008390 catalyze?
It catalyzes O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 16alpha,17beta-dihydroxyandrost-4-en-3-one + H+ + H2O + oxidized [NADPH--hemoprotein reductase].
What genes are involved in testosterone 16-alpha-hydroxylase activity?
Synonyms for the term include cytochrome P450 CYP2B10, CYP2B9, CYP2D10, CYP2D11 and CYP2D9, and the purified mouse enzyme is known as P450(16)alpha.
Is testosterone 16-alpha-hydroxylase activity inducible?
Yes, the mouse liver activity is induced by phenobarbital, which increases the responsible P450 protein.
Is testosterone 16-alpha-hydroxylase activity female-predominant?
Yes, the mouse liver activity shows female-predominant expression and is repressed in the strain 129/J background.
How is testosterone 16-alpha-hydroxylase activity measured?
It is typically measured by incubating testosterone with microsomes or recombinant P450 in the presence of an NADPH-regenerating system and quantifying the 16-alpha-hydroxylated product.
Does human cytochrome P450 have 16-alpha-hydroxylase activity?
Human cytochrome P450 17 alpha-hydroxylase can catalyze progesterone 16 alpha-hydroxylase activity, and estrogen 16 alpha-hydroxylase activity has been detected in human fetal tissues.
Is 16-alpha-hydroxylase activity linked to cancer?
Elevated estrogen 16 alpha-hydroxylase activity has been discussed as a biomarker in breast cancer risk and is increased in women with breast and endometrial cancer.
How can CRISPR help study testosterone 16-alpha-hydroxylase activity?
CRISPR knockout, point mutation, knock-in and overexpression models can test whether a candidate P450 gene is required for or sufficient to produce 16-alpha-hydroxylation of testosterone.
Conclusion
GO:0008390, testosterone 16-alpha-hydroxylase activity, defines a specific cytochrome P450 monooxygenation reaction that converts testosterone to 16alpha,17beta-dihydroxyandrost-4-en-3-one using O2 and reduced NADPH--hemoprotein reductase. The activity is best characterized in mouse liver, where it is phenobarbital-inducible, female-predominant, and repressed in strain 129/J, and it overlaps with related progesterone and estrogen 16-alpha-hydroxylase activities in humans. These features make it a valuable model for studying P450 regio- and stereospecificity and for interpreting steroid hormone metabolism in endocrine and cancer research. For researchers, precise genetic models are essential to assign GO:0008390 to the correct P450 gene and to distinguish it from related hydroxylase activities. CRISPR-based knockout, point-mutation, knock-in and overexpression approaches provide the causal evidence needed to connect genotype to steroid hydroxylation phenotype.
References
- 1. Swart P et al.. 1993. Progesterone 16 alpha-hydroxylase activity is catalyzed by human cytochrome P450 17 alpha-hydroxylase.. J Clin Endocrinol Metab 77(1):98-102 PMID: 8325965
- 2. Nebert DW. 1993. Elevated estrogen 16 alpha-hydroxylase activity: is this a genotoxic or nongenotoxic biomarker in human breast cancer risk?. J Natl Cancer Inst 85(23):1888-91 PMID: 8230275
- 3. Milewich L et al.. 1986. Estrogen 16 alpha-hydroxylase activity in human fetal tissues.. J Clin Endocrinol Metab 63(2):404-6 PMID: 3722330
- 4. Devore K et al.. 1985. Characterization of testosterone 16 alpha-hydroxylase (I-P-450(16) alpha) induced by phenobarbital in mice.. Biochemistry 24(20):5632-7 PMID: 4074718
- 5. Harada N et al.. 1984. Mouse liver testosterone 16 alpha-hydroxylase (cytochrome P-450(16) alpha). Purification, regioselectivity, stereospecificity, and immunochemical characterization.. J Biol Chem 259(19):12285-90 PMID: 6434540
- 6. Fishman J et al.. 1984. Increased estrogen-16 alpha-hydroxylase activity in women with breast and endometrial cancer.. J Steroid Biochem 20(4B):1077-81 PMID: 6727352
- 7. Noshiro M et al.. 1986. Female-predominant expression of testosterone 16 alpha-hydroxylase ("I"-P-450(16)alpha) and its repression in strain 129/J.. Arch Biochem Biophys 244(2):857-64 PMID: 3753840
- 8. Inoue K et al.. 1997. Relationship between CYP2C9 and 2C19 genotypes and tolbutamide methyl hydroxylation and S-mephenytoin 4'-hydroxylation activities in livers of Japanese and Caucasian populations.. Pharmacogenetics 7(2):103-13 PMID: 9170147
