ABSTRACT
TLE1 is an oncogenic transcriptional co-repressor that exerts its repressive effects through binding of transcription factors. Inhibition of this protein-protein interaction represents a putative cancer target, but no small-molecule inhibitors have been published for this challenging interface. Herein, the structure-enabled design and synthesis of a constrained peptide inhibitor of TLE1 is reported. The design features the introduction of a four-carbon-atom linker into the peptide epitope found in many TLE1 binding partners. A concise synthetic route to a proof-of-concept peptide, cycFWRPW, has been developed. Biophysical testing by isothermal titration calorimetry and thermal shift assays showed that, although the constrained peptide bound potently, it had an approximately five-fold higher Kd than that of the unconstrained peptide. The co-crystal structure suggested that the reduced affinity was likely to be due to a small shift of one side chain, relative to the otherwise well-conserved conformation of the acyclic peptide. This work describes a constrained peptide inhibitor that may serve as the basis for improved inhibitors.
Subject(s)
Oligopeptides/chemical synthesis , Peptides, Cyclic/chemical synthesis , Repressor Proteins/antagonists & inhibitors , Amino Acid Sequence , Binding Sites , Co-Repressor Proteins , Humans , Magnetic Resonance Spectroscopy/methods , Mass Spectrometry/methods , Oligopeptides/chemistry , Peptides, Cyclic/chemistry , Protein Binding , Protein Conformation , Repressor Proteins/chemistry , ThermodynamicsABSTRACT
The bromodomain containing proteins BAZ2A/B play essential roles in chromatin remodeling and regulation of noncoding RNAs. We present the structure based discovery of a potent, selective, and cell active inhibitor 13 (BAZ2-ICR) of the BAZ2A/B bromodomains through rapid optimization of a weakly potent starting point. A key feature of the presented inhibitors is an intramolecular aromatic stacking interaction that efficiently occupies the shallow bromodomain pockets. 13 represents an excellent chemical probe for functional studies of the BAZ2 bromodomains in vitro and in vivo.
Subject(s)
Chromosomal Proteins, Non-Histone/antagonists & inhibitors , Drug Design , Microsomes/drug effects , Molecular Probes/chemistry , Molecular Probes/pharmacology , Triazoles/chemistry , Triazoles/pharmacology , Animals , Mice , Models, Molecular , Molecular Structure , Structure-Activity RelationshipABSTRACT
BACKGROUND: The Council for Remote Area Nurses of Australia deliver the MEC course which is the only short-course on maternity emergencies offered to non-midwifery qualified remote area nurses and Aboriginal Health Workers. The aim of the course is to improve the maternity emergency skills and knowledge of health service providers who do not have midwifery qualifications. There has been no long-term evaluation of the course since its inception. RESEARCH OBJECTIVE: To review the longer-term effectiveness of the maternity emergency care (MEC) course which was developed in consultation with the Australian College of Midwives (ACM) and rural and remote practitioners in 2003. PARTICIPANTS AND METHODS: Fifty-seven clinicians who completed the MEC course since 2003 responded to a survey. Seven remote area health managers and two course facilitators were interviewed. RESULTS: This study provides an evaluation of the experiences of non-midwives who manage maternity emergencies in the rural and remote setting; their perception of the skills, knowledge and confidence acquired through participation in the MEC program. CONCLUSIONS: The MEC course is valued by both remote health managers and practitioners. The learning activities, skills and knowledge gained are reported to be very beneficial and used by remote health practitioners.