ABSTRACT
BACKGROUND: An interprofessional clinical education model operating student-led, faculty-guided clinics partnered with rural Midwest American communities lacking health care access. PURPOSE: To evaluate how an internship, guided by the Theory of Cultural Humility, during the COVID-19 pandemic supported development of cultural humility in interprofessional health profession students. APPROACH: Nursing, exercise science, public health, and social work participants completed an internship during early phases of the COVID-19 pandemic, despite many experiences being suspended. Quantitative evaluation using pre-/postadministration of Foronda's Cultural Humility Scale was completed across 3 periods measuring change in cultural humility. RESULTS: Total scores of Foronda's Cultural Humility Scale increased for all 3 periods (n = 11, n = 74, and n = 44), demonstrated by aggregate data and statistical analysis. The largest change occurred in the first period. CONCLUSIONS: Engaging interprofessional students in experiential learning during real-life, real-time public health events creates reflection of complex practice issues while developing cultural humility.
ABSTRACT
SARS-CoV-2, a human coronavirus, is the causative agent of the COVID-19 pandemic. Its genome is translated into two large polyproteins subsequently cleaved by viral papain-like protease and main protease (Mpro). Polyprotein processing is essential yet incompletely understood. We studied Mpro-mediated processing of the nsp7-11 polyprotein, whose mature products include cofactors of the viral replicase, and identified the order of cleavages. Integrative modeling based on mass spectrometry (including hydrogen-deuterium exchange and cross-linking) and x-ray scattering yielded a nsp7-11 structural ensemble, demonstrating shared secondary structural elements with individual nsps. The pattern of cross-links and HDX footprint of the C145A Mpro and nsp7-11 complex demonstrate preferential binding of the enzyme active site to the polyprotein junction sites and additional transient contacts to help orient the enzyme on its substrate for cleavage. Last, proteolysis assays were used to characterize the effect of inhibitors/binders on Mpro processing/inhibition using the nsp7-11 polyprotein as substrate.
ABSTRACT
Rupintrivir targets the 3C cysteine proteases of the picornaviridae family, which includes rhinoviruses and enteroviruses that cause a range of human diseases. Despite being a pan-3C protease inhibitor, rupintrivir activity is extremely weak against the homologous 3C-like protease of SARS-CoV-2. In this study, the crystal structures of rupintrivir were determined bound to enterovirus 68 (EV68) 3C protease and the 3C-like main protease (Mpro) from SARS-CoV-2. While the EV68 3C protease-rupintrivir structure was similar to previously determined complexes with other picornavirus 3C proteases, rupintrivir bound in a unique conformation to the active site of SARS-CoV-2 Mpro splitting the catalytic cysteine and histidine residues. This bifurcation of the catalytic dyad may provide a novel approach for inhibiting cysteine proteases.
Subject(s)
Antiviral Agents/metabolism , Coronavirus 3C Proteases/metabolism , Cysteine Proteinase Inhibitors/metabolism , Isoxazoles/metabolism , Phenylalanine/analogs & derivatives , Pyrrolidinones/metabolism , SARS-CoV-2/enzymology , Valine/analogs & derivatives , Antiviral Agents/chemistry , Catalytic Domain , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus 3C Proteases/chemistry , Crystallography, X-Ray , Cysteine Proteinase Inhibitors/chemistry , Enterovirus D, Human/enzymology , Hydrogen Bonding , Isoxazoles/chemistry , Phenylalanine/chemistry , Phenylalanine/metabolism , Protein Binding , Pyrrolidinones/chemistry , Static Electricity , Valine/chemistry , Valine/metabolismABSTRACT
Coronavirus (CoV) nonstructural proteins (nsps) assemble to form the replication-transcription complex (RTC) responsible for viral RNA synthesis. nsp7 and nsp8 are important cofactors of the RTC, as they interact and regulate the activity of RNA-dependent RNA polymerase and other nsps. To date, no structure of the full-length SARS-CoV-2 nsp7:nsp8 complex has been published. The current understanding of this complex is based on structures from truncated constructs, with missing electron densities, or from related CoV species where SARS-CoV-2 nsp7 and nsp8 share upward of 90% sequence identity. Despite available structures solved using crystallography and cryo-EM representing detailed static snapshots of the nsp7:nsp8 complex, it is evident that the complex has a high degree of structural plasticity. However, relatively little is known about the conformational dynamics of the individual proteins and how they complex to interact with other nsps. Here, the solution-based structural proteomic techniques, hydrogen-deuterium exchange mass spectrometry (HDX-MS) and cross-linking mass spectrometry (XL-MS), illuminate the dynamics of SARS-CoV-2 full-length nsp7 and nsp8 proteins and the nsp7:nsp8 protein complex. Results presented from the two techniques are complementary and validate the interaction surfaces identified from the published three-dimensional heterotetrameric crystal structure of the SARS-CoV-2 truncated nsp7:nsp8 complex. Furthermore, mapping of XL-MS data onto higher-order complexes suggests that SARS-CoV-2 nsp7 and nsp8 do not assemble into a hexadecameric structure as implied by the SARS-CoV full-length nsp7:nsp8 crystal structure. Instead, our results suggest that the nsp7:nsp8 heterotetramer can dissociate into a stable dimeric unit that might bind to nsp12 in the RTC without significantly altering nsp7-nsp8 interactions.