Sandbox 45673: Difference between revisions

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Typically 5α-redcutase  turns testosterone into Dihydrotestosterone(DHT), but the enzyme will accept  Finasteride as an alternate substrate; turning it into dihydrofinasteride through an enzyme bound, NADP-dihydrofinasteride adduct. Finasteride is similar in structure to testosterone and 5alpha-reductase has almost the same affinity for both molecules. However, Finasteride , having a high affinity for 5α-reductase, covalently  binds to the enzyme as a Michael acceptor, through a functionally irreversible reaction. However, the NADP-dihydrofinasteride complex breaks down with a half life of about 1 month at 37˚C., which is why patients must continue taking the drug.<ref name="five"> Bull, Herbert G.*Garcia-Calvo,Margarita Andersson,Stefan†, Baginsky, Walter F.,Chan,H. Karen,Ellsworth,‡ Dina E., Miller,§ Randall R., Stearns,Ralph A.,Bakshi,Raman K.,Rasmusson, Gary H.,Tolman,Richard L., Myers,Robert W.,Kozarich,John W.,Harris,Georgianna S. (1995, August 6) Mechanism-Based Inhibition of Human Steroid 5R-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor. http://pubs.acs.org/doi/pdf/10.1021/ja953069t</ref>
Typically 5α-redcutase  turns testosterone into Dihydrotestosterone(DHT), but the enzyme will accept  Finasteride as an alternate substrate; turning it into dihydrofinasteride through an enzyme bound, NADP-dihydrofinasteride adduct. Finasteride is similar in structure to testosterone and 5alpha-reductase has almost the same affinity for both molecules. However, Finasteride , having a high affinity for 5α-reductase, covalently  binds to the enzyme as a Michael acceptor, through a functionally irreversible reaction. However, the NADP-dihydrofinasteride complex breaks down with a half life of about 1 month at 37˚C., which is why patients must continue taking the drug.<ref name="five"> Bull, Herbert G.*Garcia-Calvo,Margarita Andersson,Stefan†, Baginsky, Walter F.,Chan,H. Karen,Ellsworth,‡ Dina E., Miller,§ Randall R., Stearns,Ralph A.,Bakshi,Raman K.,Rasmusson, Gary H.,Tolman,Richard L., Myers,Robert W.,Kozarich,John W.,Harris,Georgianna S. (1995, August 6) Mechanism-Based Inhibition of Human Steroid 5R-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor. http://pubs.acs.org/doi/pdf/10.1021/ja953069t</ref>


[[Image: Biochem group project.PNG|thumb|left|'''Fig. 1'''. Structure of OM99-2.]]
[[Image: Biochem group project.PNG|thumb|left|'''Fig. 1'''. Proposed mechanism of inhibition by Bull et. al. Image shows how the inhibition of 5alpha-reductase is achieved  as Finasteride is used as a substrate to create an enolate intermediate, similar to the one made  during the reduction of testosterone. However, the complex created does not allow for the proton transfer needed to complete the reduction of NADP-Dihydrofinasteride  to Finasteride, because of the change in the carbanion position<ref name="five">Bull, Herbert G.*Garcia-Calvo,Margarita Andersson,Stefan†, Baginsky, Walter F.,Chan,H. Karen,Ellsworth,‡ Dina E., Miller,§ Randall R., Stearns,Ralph A.,Bakshi,Raman K.,Rasmusson, Gary H.,Tolman,Richard L., Myers,Robert W.,Kozarich,John W.,Harris,Georgianna S. (1995, August 6) Mechanism-Based Inhibition of Human Steroid 5R-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor. http://pubs.acs.org/doi/pdf/10.1021/ja953069t</ref></font>
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Revision as of 02:21, 6 December 2016

N-(1,1-dimethylethyl)-3-oxo-(5α,17β)-4-azaandrost-1-ene-17-carboxamide

N-(1,1-dimethylethyl)-3-oxo- (5α,17β)-4-azaandrost-1-ene-17-carboxamide bound to 5α-reductase (PDB code 3g1r)

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References

Allen, Helen. (2015, March). "Finasteride for prostate gland enlargement. Information. Patient.

Bull, Herbert G.*Garcia-Calvo,Margarita Andersson,Stefan†, Baginsky, Walter F.,Chan,H. Karen,Ellsworth,‡ Dina E., Miller,§ Randall R., Stearns,Ralph A.,Bakshi,Raman K.,Rasmusson, Gary H.,Tolman,Richard L., Myers,Robert W.,Kozarich,John W.,Harris,Georgianna S. (1995, August 6) Mechanism-Based Inhibition of Human Steroid 5R-Reductase by Finasteride: Enzyme-Catalyzed Formation of NADP-Dihydrofinasteride, a Potent Bisubstrate Analog Inhibitor. https://pubs.acs.org/doi/pdf/10.1021/ja953069t

Leyden, J., Dunlap, F., & Miller, B., et el. (1999, June). Finasteride in the treatment of men with frontal male pattern hair loss.

Olsen, E. A., Hordinsky, M., & Whiting, D., et al. (2006, December). The importance of dual 5α-reductase inhibition in the treatment of male pattern hair loss: Results of a randomized placebo-controlled study of dutasteride versus finasteride.

Schieck, Cynthia L.(1998, August) "Finasteride (Propecia ®)". https://www.chm.bris.ac.uk/motm/finasteride/Finasteride%20(Propecia)%20-%20Feature%20Molecule.htm