Measurement of the binding force between RAS protein and a pathologic BRAF mutant using optical tweezers

Abstract

Activating mutants in rat sarcoma (RAS) and B-rapid accelerated fibrosarcoma (BRAF) are found in at least a third of cases of human tumors and melanoma; hence, numerous therapeutic treatments target this pathway. In this letter, we study the adhesion force of RAS-coated beads with BRAF-coated beads, BRAF (A246P) mutant-coated beads, and GST-coated beads using optical tweezers. One full and two fractional RAS-BRAF specific binding modes are identified using the rupture force distribution. The koff (0) of the full binding mode in RAS-BRAF is 3.71×10-4/s and 1.16×10-4s-1 in RAS-BRAF (A246P), whereas the xb is around 3 \times 10-10 m in both groups.