KRAS G12C Protein, Human, Recombinant, Biotinylated, GDP-Loaded

N-terminal AviTag™, N-terminal 8XHis

High-purity KRAS G12C protein supplied in a defined GDP-loaded conformation for controlled biochemical workflows, including SPR, BLI, ELISA, pull-down, AlphaScreen, MST, nucleotide exchange assays, SOS1-mediated exchange assays, and oncology drug discovery applications.

Available Sizes

0.05 mg
$ 500.00
0.1 mg
$ 750.00
1.0 mg
$ 5,500.00

Ships with Certificate of Analysis (CoA)

Product Overview

KRAS G12C is the target of the first approved direct KRAS inhibitor (sotorasib/AMG-510, FDA 2021) and adagrasib/MRTX849. Both drugs covalently modify Cys12, the unique cysteine introduced by the G12C substitution, and lock KRAS in the inactive GDP-bound state. Understanding the mechanism of covalent engagement, screening next-generation G12C inhibitors, and developing resistance mutation panels all require KRAS G12C protein in the GDP conformation with the Cys12 accessible.

This product provides recombinant human KRAS G12C (isoform KRAS4B, aa 1–185), site-specifically biotinylated at the N-terminal AviTag™ and pre-loaded with GDP. The free Cys12 is maintained in reduced form by the 2-mercaptoethanol in the storage buffer. Researchers screening covalent G12C inhibitors should be aware that covalent modification at Cys12 by test compounds will irreversibly occupy the binding site — see technical note below.

Key Features

  • KRAS G12C clinically relevant mutation
  • Supplied pre-loaded with GDP
  • N-terminal AviTag™, N-terminal 8XHis tagged construct
  • Site-specifically biotinylated at the N-terminus
  • High purity recombinant protein
  • Optimized for binding assays
  • Research Use Only (RUO)

Applications

  • SPR
  • BLI
  • ELISA
  • Pull-down
  • AlphaScreen
  • MST
  • Nucleotide exchange assays
  • SOS1-mediated exchange assays
  • Protein–protein interaction studies
  • Drug discovery workflows

Technical Notes

Covalent inhibitor handling

KRAS G12C covalent inhibitors (acrylamides, vinyl sulfonamides) irreversibly modify Cys12. Once modified, the protein cannot be returned to the unmodified state. Plan your assay accordingly: pre-titrate inhibitor concentration to achieve defined fractional occupancy, or use mass spectrometry to confirm modification stoichiometry. DMSO stock solutions of covalent inhibitors should be freshly diluted into assay buffer immediately before use.

Reducing agent compatibility

The storage buffer contains 1 mM 2-mercaptoethanol (2-ME) to maintain Cys12 in the reduced (reactive) state. 2-ME is compatible with most downstream assay formats at this concentration. If your assay is sensitive to thiol-based reducing agents, substitute with 0.5 mM TCEP; do not use DTT above 1 mM (can compete with covalent inhibitors for Cys12). Dilute the protein into your assay buffer immediately before use to minimize thiol oxidation.

GppNHp-loaded G12C available

For applications requiring active conformation KRAS G12C (GTP-locked), see KRAS G12C Protein, Biotinylated, GppNHp-Loaded. Note that GppNHp-loaded G12C has Cys12 occupied by the conformational change in switch II, which may reduce accessibility to some covalent inhibitors — use GDP-loaded for covalent mechanism studies.

Biological Context & Applications

Cancer Indications

Non-small cell lung cancer (NSCLC), colorectal cancer, pancreatic cancer, lung adenocarcinoma, bladder cancer (subset), head and neck cancer (subset)

Binding Partners

RAF1, BRAF, PI3K, RalGDS, SOS1

Application Notes

Standard for KRAS inhibitor screening and biochemical assays

Protein Specifications

Gene KRAS
Mutation G12C
Nucleotide State GDP-Loaded
Organism Human
Tag N-terminal AviTag™, N-terminal 8XHis
Expression System E. coli
Purity >90% by Coomassie staining
Endotoxin <1 EU/mg
Biotinylated Yes
Oncogenic Status Oncogenic
Assay Compatibility SPR, BLI, ELISA, Pull-down, AlphaScreen, MST, Nucleotide exchange assays, SOS1-mediated exchange assays
UniProt ID P01116-2
Amino Acid Range 1-185
Buffer 20 mM HEPES, pH 7.5, 100 mM NaCl, 1 mM MgCl2, 1 mM 2-mercapthoethanol, 10% glycerol
Storage -80 °C

Quality Control

  • Purity validated by SDS-PAGE
  • Identity confirmed by mass spectrometry
  • Assay compatibility verified
  • A Certificate of Analysis (CoA) is provided with every shipment

Ordering Information

Size Catalog No. Price Quote
0.05 mg KRAS12C-GDP-301-005 $ 500.00 Request Quote
0.1 mg KRAS12C-GDP-301-01 $ 750.00 Request Quote
1.0 mg KRAS12C-GDP-301-1 $ 5,500.00 Request Quote
Need larger quantities or custom formats? We offer bulk pricing and custom production.
Request Bulk Quote

Typical response time: 1 business day

Custom Services

Need a different format, mutation, or production scale? We offer custom RAS protein engineering tailored to your research.

Custom Mutations

Alternative KRAS variants, including rare and novel mutations.

Tag & Labeling Options

His-tag, AviTag™, biotinylation, fluorescent labeling, or tag-free formats.

Scale-Up Production

From research-scale to bulk manufacturing for screening and preclinical work.

Protein Complexes

Complex formation such as KRAS–RAF-RBD and other binding partners.

Nucleotide Loading

Pre-load KRAS proteins with defined nucleotides, including GppNHp (non-hydrolyzable GTP analog) or GDP, for consistent assay-ready performance.

Tell us your mutation, format, or assay requirements and we’ll provide a tailored quote.

Request Custom Quote Email Us

Fast turnaround • Dedicated scientific support • Confidential projects

Related Products

Other KRAS mutants and formats available.

Research Use Only. Not for diagnostic or therapeutic use.