Monobody Inhibitor Selective to the Phosphatase Domain of SHP2 and its Use as a Probe for Quantifying SHP2 Allosteric Regulation.

SHP2 is a phosphatase/adaptor protein that plays an important role in various signaling pathways. Its mutations are associated with cancers and developmental diseases. SHP2 contains a protein tyrosine phosphatase (PTP) and two SH2 domains. Selective inhibition of these domains has been challenging due to the multitude of homologous proteins in the proteome. Here, we developed a monobody, synthetic binding protein, that bound to and inhibited the SHP2 PTP domain. It was selective to SHP2 PTP over close homologs. A crystal structure of the monobody-PTP complex revealed that the monobody bound both highly conserved residues in the active site and less conserved residues in the periphery, rationalizing its high selectivity. Its epitope overlapped with the interface between the PTP and N-terminal SH2 domains that is formed in auto-inhibited SHP2. By using the monobody as a probe for the accessibility of the PTP active site, we developed a simple, nonenzymatic assay for the allosteric regulation of SHP2. The assay showed that, in the absence of an activating phospho-Tyr ligand, wild-type SHP2 and the "PTP-dead" C459E mutant were predominantly in the closed state in which the PTP active site is inaccessible, whereas the E76K and C459S mutants were in the open, active state. It also revealed that previously developed monobodies to the SH2 domains, ligands lacking a phospho-Tyr, weakly favored the open state. These results provide corroboration for a conformational equilibrium underlying allosteric regulation of SHP2, provide powerful tools for characterizing and controlling SHP2 functions, and inform drug discovery against SHP2.

Development of a health equity journal club to address health care disparities and improve cultural competence among emergency medicine practitioners.

Health care disparities have been magnified by the COVID-19 pandemic. Only recently has the medical community acknowledged implicit bias and systemic racism as a public health emergency. Graduate medical education has been slow to adopt curricula beyond lecture-based formats that specifically address social determinants of health (SDOH) and its impact on communities. Curricula addressing unconscious (implicit) biases and their influence on patient care has not been widely adopted. The emergency department (ED) has a unique role in addressing health care disparities. Approximately 69% of emergency medicine residency programs incorporate cultural competency training in their curricula. Most are primarily lecture-based without a longitudinal component, and gaps exist in content, quality, and expertise of the presenters. Lecture-based formats may not be best suited to manage the nuanced conversations necessary to dismantle biases and socialized beliefs that result in disparities for marginalized communities. Reporting little or no education in medical school related to SDOH, residents acknowledge that barriers to care exist, but have limited or no knowledge of what those barriers are or how mitigate them. To improve health equity, understanding and competence in caring for culturally and ethnically diverse populations, we developed a monthly, longitudinal, SDOH- and cultural competency-based "health equity journal club" (HEJC) for all levels of ED staff. Four educational domains were developed, and specific content within each domain was selected based on predetermined criteria. Content for each session was mapped to the ACGME program and core competency milestone requirements, ACGME Clinical Learning Environment (CLER) mandates, and The Joint Commission's institutional recommendations for culturally competent care. The HEJC series has been successful in reducing barriers to identifying biases in health care; translating literature to clinical care; generating initiatives and interdisciplinary research; and cultivating interest in community health, health advocacy, and public policy.