Binding thermodynamics of statins to HMG-CoA reductase

Teresa Carbonell, Ernesto Freire

Research output: Contribution to journalArticlepeer-review

Abstract

The statins are powerful inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMG-CoA reductase), the key enzyme in the cholesterol biosynthetic pathway, and are among the most widely prescribed drugs in the world. Despite their clinical importance, little is known about the binding thermodynamics of statins to HMG-CoA reductase. In this paper, we report the results of inhibition kinetics and microcalorimetric analysis of a representative type I statin (pravastatin) and four type II statins (fluvastatin, cerivastatin, atorvastatin, and rosuvastatin). Inhibition constants (Ki) range from 2 to 250 nM for the different statins. Isothermal titration calorimetry (ITC) experiments yield binding enthalpies (ΔHbinding) ranging between zero and -9.3 kcal/mol at 25 °C. There is a clear correlation between binding affinity and binding enthalpy: the most powerful statins bind with the strongest enthalpies. The proportion by which the binding enthalpy contributes to the binding affinity is not the same for all statins, indicating that the balance among hydrogen bonding, van der Waals, and hydrophobic interactions is not the same for all of them. At 25 °C, the dominant contribution to the binding affinity of fluvastatin, pravastatin, cerivastatin, and atorvastatin is the entropy change. Only for rosuvastatin does the enthalpy change contribute more than 50% of the total binding energy (76%). Since the enthalpic and entropic contributions to binding originate from different types of interactions, the thermodynamic dissection presented here provides a way to identify interactions that are critical for affinity and specificity.

Original languageEnglish (US)
Pages (from-to)11741-11748
Number of pages8
JournalBiochemistry
Volume44
Issue number35
DOIs
StatePublished - Sep 6 2005

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Binding thermodynamics of statins to HMG-CoA reductase'. Together they form a unique fingerprint.

Cite this