Design and Synthesis of BRCA1 (856-871) Analogous and their Interactions with RAD51 (158-180)

Breast cancer susceptibility gene 1 (BRCA1) is an important tumor suppressor gene in the human which associated with a variety of tumor suppressor genes to inhibit the growth of malignant tumors. Breast cancer is closely related to BRCA1 mutations in humans. Four BRCA1 (856-871) mutants were screened that can interact well with RAD51 (158-180) using computer to simulate mutations at Y 856, R 866 and Q 867. These mutants were synthesized by using Fmoc solid-phase synthesis, and purified by liquid chromatography. According to the results of fluorescence spectroscopy, R866W has the strongest binding ability for the above peptides and RAD51 (158-180). Based on the circular dichroism spectrum results, the sequence of the interaction ability of the above peptides on the secondary structure of RAD51 (158-180) is Y856P, Q867C > Y856P, R866W ≈ R866W > Y856P > BRCA1. All the spectral results show that R866W have the strongest interaction ability with RAD51(158-180).