Fragment-based Design Of BRD4 Inhibitors

Bromodomain(BRDs)is a functional domain of bromine protein containing about 110 amino acids.It can specifically recognize the conserved protein domain of acetyllysine,participate in the transmission of histone acetylation signal,and then regulate gene transcription.Many human diseases are closely related to BET protein.Bromine domain recognition protein 4(BRD4)regulates transcriptional extension through positive transcriptional elongation factors,which is the key mediator of transcriptional extension.Combining with transcriptional initiation sites,BRD4 affects mitosis,and its expression disorder is associated with many cancers.Targeted drugs targeting this protein compete with the recognition sequence of acetyllysine to induce apoptosis and slow proliferation of cancer cells in order to achieve the goal of anti-cancer.Therefore,the study of BRD4 protein inhibitors has become a hot topic in the field of biochemistry in recent years.However,only a small number of related inhibitors have been reported,and the structure type is relatively single.Fragment-based drug design(FBDD)is a new drug discovery method that combines random screening with structure-based drug design.Fragment-based drug design has been applied in many laboratories and has produced drugs for clinical trials.Biofilm interferometry(BLI)is the fastest growing label-free detection technology in the world.It can monitor the binding process of the whole molecule in real time,and calculate the affinity(KD),binding rate(ka),dissociation rate(kd)and other important data.It can provide real-time,non-labeled information of intermolecular interaction and content detection.Five small molecules with high binding activity were screened by biolayer interference as the initial compounds for protein eutectic using the idea of "fragment-based drug design".In this experiment,the crystallization conditions of protein-compound complex crystals with resolution better than 1.2 A were screened.X-ray diffraction is the most effective and accurate method to study molecular structure.By means of co-crystallization,target proteins can be quickly identified and combined with active fragments.The three-dimensional structure of target proteins can be quickly determined and resolved by X-ray diffraction crystal technology,and the binding site information is clear.In this experiment,high-resolution crystal structure was obtained by X-ray diffraction,and the binding characteristics of compounds and proteins were studied.On this basis,compounds were designed and modified,and the binding rules of compounds were systematically studied.Finally,high-activity and high-specificity inhibitors with new structures were designed,which provided theoretical guidance for the design of targeted drugs for this protein.