Orlistat response to missense mutations in lipoprotein lipase

Area of Science:

• Biochemistry
• Pharmacology
• Molecular Biology

Background:

• Human lipoprotein lipase (LPL) is a key target for obesity treatment.
• Orlistat, an LPL inhibitor, is used for obesity-related conditions like diabetes and cardiovascular diseases.
• Missense mutations in LPL can affect orlistat efficacy, limiting its clinical use.

Purpose of the Study:

• To investigate the impact of 16 disorder-associated missense mutations in the LPL catalytic domain on orlistat binding and inhibition.
• To understand how these mutations influence orlistat response in the context of obesity therapy.

Main Methods:

• Molecular dynamics simulations were employed to analyze the binding of orlistat to mutated LPL.
• Enzyme inhibition assays were conducted to assess the functional consequences of these mutations.
• Structural and energetic analyses were performed to elucidate the mechanisms of altered drug response.

Main Results:

• Most LPL mutations had a minor effect on orlistat binding.
• Three mutations (Trp86Arg, Ile194Thr, Glu242Lys) significantly reduced orlistat binding affinity (unfavorable).
• Two mutations (His136Arg, Gly188Glu) enhanced orlistat binding affinity (favorable).

Conclusions:

• Specific LPL mutations can considerably alter orlistat's binding affinity and inhibitory activity.
• These mutations induce orlistat resistance or sensitization through direct interaction changes or allosteric effects.
• Understanding these mutation-drug interactions is crucial for optimizing orlistat therapy in obesity treatment.