Parallel screening of low molecular weight fragment libraries: do differences in methodology affect hit...

Area of Science:

• Biochemistry
• Structural Biology
• Drug Discovery

Background:

• Fragment screening is a key strategy for identifying novel drug leads.
• HIV-1 integrase (IN) is a critical target for antiviral therapies.
• Independent fragment screening campaigns were conducted on the HIV-1 IN core domain.

Purpose of the Study:

• To compare two different fragment screening methodologies for HIV-1 IN.
• To evaluate the effectiveness of STD-NMR and SPR in identifying fragment hits.
• To analyze factors influencing fragment-based lead discovery outcomes.

Main Methods:

• Two independent fragment screening campaigns were performed on HIV-1 IN.
• Screening methods included saturation transfer difference nuclear magnetic resonance spectroscopy (STD-NMR) and surface plasmon resonance (SPR).
• All initial fragment hits were validated using X-ray crystallography.

Main Results:

• The STD-NMR/X-ray approach identified 15 IN/fragment complexes.
• The SPR/X-ray approach identified 6 IN/fragment complexes.
• Despite different initial hits, both methods revealed viable binding sites on IN.

Conclusions:

• Both STD-NMR and SPR, when coupled with crystallography, are effective for fragment-based lead discovery against HIV-1 IN.
• The choice of screening conditions and hit classification criteria significantly impacts the identified fragments.
• Complementary data from different screening approaches can enhance fragment-based drug discovery efforts.