Sandbox 55: Difference between revisions
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==HMG-CoA Reductase== | ==HMG-CoA Reductase== | ||
<applet load='1hwk' size='400' frame='true' align='right' caption='HMG-CoA Reductase in complex with Lipitor' /> | <applet load='1hwk' size='400' frame='true' align='right' caption='HMG-CoA Reductase in complex with Lipitor' /> | ||
HMG-CoA is an endoplasmic reticulum transmembrane glycoprotein. It is an NADPH-dependent enzyme. | |||
===Mechanism of Action=== | ===Mechanism of Action=== | ||
[[Image:Statin_mechanism.gif]] | [[Image:Statin_mechanism.gif]] | ||
In the normal catalytic mechanism of converting HMG-CoA to mevalonate, the carboxyl group of hydroxymethylglutarate that is in ester linkage to the thiol of coenzyme A is reduced twice via NADPH to an aldehyde and then to an alcohol. | |||
[[Image:HMGCR_mechanism.gif]] | |||
HMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonate in the cholesterol biosynthesis pathway. Atorvastatin selectively and competitively inhibits HMG-CoA reductase. The inhibition subsequently increases the expression of LDL receptors on hepatocytes, which increases LDL uptake by hepatocytes, therefore decreasing the LDL-cholesterol concentration in the blood. Atorvastatin also increases levels of HDL-cholesterol.<ref>LDL-C, Decreasing. "DrugBank: Atorvastatin (DB01076)." DrugBank: Welcome. Web. 09 Mar. 2011. <http://www.drugbank.ca/drugs/DB01076>.</ref> | HMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonate in the cholesterol biosynthesis pathway. Atorvastatin selectively and competitively inhibits HMG-CoA reductase. The inhibition subsequently increases the expression of LDL receptors on hepatocytes, which increases LDL uptake by hepatocytes, therefore decreasing the LDL-cholesterol concentration in the blood. Atorvastatin also increases levels of HDL-cholesterol.<ref>LDL-C, Decreasing. "DrugBank: Atorvastatin (DB01076)." DrugBank: Welcome. Web. 09 Mar. 2011. <http://www.drugbank.ca/drugs/DB01076>.</ref> | ||
