Details

Autor(en) / Beteiligte

• Shuman, Cynthia F.
• Markgren, Per-Olof
• Hämäläinen, Markku
• Danielson, U.Helena

Titel

Elucidation of HIV-1 protease resistance by characterization of interaction kinetics between inhibitors and enzyme variants

Ist Teil von

• Antiviral research, 2003-05, Vol.58 (3), p.235-242

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2003

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• The kinetics of the interaction between drug-resistant variants of HIV-1 protease (G48V, V82A, L90M, I84V/L90M, and G48V/V82A/I84V/L90M) and clinically used inhibitors (amprenavir, indinavir, nelfinavir, ritonavir, and saquinavir) were determined using biosensor technology. The enzyme variants were immobilized on a biosensor chip and the association and dissociation rate constants ( k on and k off) and affinities ( K D) for interactions with inhibitors were determined. A unique interaction kinetic profile was observed for each variant/inhibitor combination. Substitution of single amino acids in the protease primarily resulted in reduced affinity through increased k off for the inhibitors. For inhibitors characterized by fast association rates to wild-type protease (ritonavir, amprenavir, and indinavir), additional substitutions resulted in a further reduction of affinity by a combination of decreased k on and increased k off. For inhibitors characterized by slow dissociation rates to wild-type enzyme (saquinavir and nelfinavir), the decrease of affinity conferred by additional mutations was attributed to increased k off values. Development of resistance thus appears to be associated with a change of the distinctive kinetic parameter contributing to high affinity. Further inhibitor design should focus on improving the “weak point” of the lead compound, that being either k on or k off.