RAS-related Proteins

RAS proteins are small GTPases that exhibit high‐affinity binding to either GDP or GTP and hydrolyze bound GTP to GDP. When bound to GTP, RAS is switched “on” and activates intracellular signaling pathways, promoting cell proliferation and angiogenesis. Mutated RAS is constitutively activated and turned “on” thereby enhancing downstream signaling and leading to tumorigenesis. The development of many cancers depends on sustained expression and signaling of KRAS, which makes KRAS a high-priority therapeutic target.

WuXi Biology offers assay services for RAS drug discovery, including wildtype and mutant RAS protein purification, crystal structural analysis of apo or RAS-ligand complexes, affinity detection of small molecule compounds binding to RAS mutants, KRAS upstream and downstream protein interaction, pathway activation, and cell proliferation. View our contribution to the publication “Structure-Based Design and Synthesis of Potent and Selective KRAS G12D Inhibitors” by clicking HERE.

  • Available proteins include KRAS, HRAS, and NRAS with various tags.
  • Available mutant KRAS proteins include G12C, G12D, G12R, G12V, G12A, G12S, G13D, and Q61H
  • Available mutant NRAS proteins include Q61R, Q61K, and Q61H,
  • RAS proteins in either  GDP- or GCP-bound (GMPPCP) format
RAS-related proteins, KRAS, HRAS, NRAS, G12C, G12D, GDP, GTP

X-ray Structure Determination of KRAS with Small Molecules

The information of the binding sites between KRAS and small molecules can provide the most direct basis for the optimization of lead compounds and subsequent mechanism elucidation. WuXi Biology has optimized the crystallization conditions of KRAS protein and the co-crystallization success rate is >75% and structure resolution is < 1.8Å.

Biophysical KRAS Assays

Surface Plasmon Resonance Direct RAS Binding Assay

SPR, RAS binding assay, surface plasmon resonance, G12D

Thermal Shift Direct Binding Assay

Thermal shift direct binding assay, biophysical KRAS assay

Biochemical KRAS Assays


cRAF binding assay can be used for the identification of disruptors of interaction between RAS and cRAF, as well as detection of the nucleotide exchange reaction. KRAS and cRAF interaction assay is used for compound screening in AlphaLISA format. The assay is available for wildtype and various KRAS mutants.

RAS, PPI interaction assay


KRAS and SOS1 interaction assay is used for the identification of SOS1-KRAS disruptors using the HTRF assay format.

The assay is available for wildtype and various KRAS mutants.

SOS1, KRAS, HTRF, interaction PPI assay

Cell-based KRAS Assays

– High throughput cellular assay for the determination of levels of phosphorylated ERK protein.

Phosphorylation of ERK is an important marker of KRAS activation in cells. WuXi Biology has established a cell-based detection method for pERK using the Licor fluorescence technique. Reference inhibitor of the KRSAS mutants effectively reduced pERK level in cells.

cell-based phosphorylation assay, ERK protein, high throughput cellular assay
– 2D/3D cell proliferation assay

Cell proliferation assay in sensitive cell lines of each KRAS inhibitor target group with 2D/3D assay format is available.

cell proliferation assay, 2d/3d KRAS

pERK HTRF assay is used for the determination of KRAS inhibitors by assessing the inhibition of ERK phosphorylation (pERK) in cell lines.

pERK, HTRF, KRAS phosphorylation