Product Description

KRAS[G12D] is one of the most common activating mutations of KRAS, causing defective GTP hydrolysis and constitutive KRAS activation. SOS1, a guanine nucleotide exchange factor (GEF), catalyzes the conversion of KRAS from GDP‑bound to GTP‑bound state, activating downstream proliferation and survival signals. The KRAS[G12D]/SOS1 interaction sustains oncogenic signaling in tumor cells and is prevalent in pancreatic, colorectal, and lung cancers. Small‑molecule inhibitors targeting this interaction (e.g., BI‑3406) effectively suppress mutant‑driven tumor growth, underscoring its therapeutic value in cancer.

Screeningbio’s TR-FRET GDP‑loaded KRAS[G12D]/SOS1 Binding Assay Kit can be used to measure the interaction between KRAS[G12D] (loaded with GDP) and SOS1 protein. This kit, developed using TR‑FRET technology, is suitable for high‑throughput screening of small‑molecule inhibitors, peptides, or antibody blockers, and is characterized by simplicity, rapidity, and high accuracy.

The basic principle of this method is as illustrated in the figure below: an anti‑Tag 2 antibody conjugated to Solar Eu*1 specifically recognizes SOS1 protein bearing Tag 2, while an anti‑Tag 1 antibody conjugated to LA*2 recognizes KRAS[G12D] protein bearing Tag 1. When SOS1 binds to KRAS[G12D], the tag antibodies conjugated to Solar Eu and LA, respectively, are brought into close proximity. Upon excitation by an external light source, fluorescence resonance energy transfer occurs between the donor and acceptor. The interaction level between KRAS[G12D] and SOS1 protein can be determined by measuring the signal intensity at a specific wavelength (665 nm). Consequently, compounds, peptides, or antibodies that block the KRAS[G12D]/SOS1 interaction will result in a decrease in the TR‑FRET signal.