G-quadruplex structure of an anti-proliferative DNA sequence

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• AGRO100 (AS1411) is a G-rich oligonucleotide with established anti-cancer properties.
• The precise G-quadruplex structure of AGRO100 has been elusive due to conformational heterogeneity.

Purpose of the Study:

• To identify and characterize a G-rich DNA sequence forming a single, stable G-quadruplex conformation.
• To elucidate the solution structure of this novel G-quadruplex and its relationship to anti-proliferative activity.

Main Methods:

• Derivation of the AT11 DNA sequence from AGRO100.
• Determination of the solution structure of the AT11 G-quadruplex using biophysical techniques.
• Assessment of anti-proliferative activity of AT11.

Main Results:

• The AT11 sequence forms a single major G-quadruplex conformation.
• The solution structure reveals a four-layer G-quadruplex with two propeller-type parallel-stranded subunits.
• AT11 demonstrates anti-proliferative activity comparable to AGRO100.

Conclusions:

• The determined structure of AT11 provides insights into G-quadruplex folding principles.
• Understanding this structure facilitates the rational design and optimization of anti-cancer oligonucleotides.