Characterization of potassium binding with human telomeres

Area of Science:

• Biochemistry
• Structural Biology
• Medicinal Chemistry

Background:

• Human telomeres consist of G-rich repeats forming G-quadruplex structures.
• Telomeric G-quadruplex stabilization is a key strategy for inhibiting cancer-promoting telomerase activity.
• The precise mechanism of metal ion binding to human telomeric G-quadruplexes is not fully understood.

Purpose of the Study:

• To elucidate the atomic-level interactions between potassium ions (K+) and human telomeric G-quadruplex structures.
• To understand the role of water molecules in the binding process and stabilization of the complex.
• To provide insights for the rational design of drugs targeting telomeric G-quadruplexes.

Main Methods:

• Computational modeling and simulation of K+ binding to human telomeric G-quadruplex.
• Analysis of electrostatic interactions and steric effects during ion translocation.
• Investigation of water molecule dynamics and their role in complex stabilization.

Main Results:

• K+ ions traverse into the center of G-tetrad layers via a pathway formed by loop bases.
• Electrostatic interactions mediate the binding of K+ to G-tetrad bases.
• Water molecules hinder initial K+ entry but stabilize the final G-quadruplex-K+ complex.
• The binding leads to stabilization of the in-plane or sandwiched conformation of the telomeric G-quadruplex-K+ complex.

Conclusions:

• Potassium ion binding to human telomeric G-quadruplexes involves specific pathways and interactions.
• Water molecules play a dual role in regulating K+ binding and stabilizing the complex.
• Understanding these atomic interactions is crucial for developing novel anticancer therapeutics targeting telomeres.