RESUMO
Small heat shock proteins (sHsps) are molecular chaperones employed to interact with a diverse range of substrates as the first line of defense against cellular protein aggregation. The N-terminal region (NTR) is implicated in defining features of sHsps; notably in their ability to form dynamic and polydisperse oligomers, and chaperone activity. The physiological relevance of oligomerization and chemical-scale mode(s) of chaperone function remain undefined. We present novel chemical tools to investigate chaperone activity and substrate specificity of human HspB1 (B1NTR), through isolation of B1NTR and development of peptide-conjugated gold nanoparticles (AuNPs). We demonstrate that B1NTR exhibits chaperone capacity for some substrates, determined by anti-aggregation assays and size-exclusion chromatography. The importance of protein dynamics and multivalency on chaperone capacity was investigated using B1NTR-conjugated AuNPs, which exhibit concentration-dependent chaperone activity for some substrates. Our results implicate sHsp NTRs in chaperone activity, and demonstrate the therapeutic potential of sHsp-AuNPs in rescuing aberrant protein aggregation.
Assuntos
Proteínas de Choque Térmico Pequenas/química , Proteínas de Choque Térmico/química , Nanopartículas Metálicas/química , Chaperonas Moleculares/química , Sequência de Aminoácidos/genética , Ouro/química , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico Pequenas/genética , Humanos , Modelos Moleculares , Chaperonas Moleculares/genética , Agregados Proteicos/genética , Ligação Proteica/genética , Dobramento de Proteína , Multimerização Proteica/genética , Especificidade por SubstratoRESUMO
Objective: To assess depression, anxiety, and burnout among health care workers using well-established validated scales and to examine associations of these mental health outcomes with personal protective equipment (PPE) and high-risk patient contact.Methods: This prospective survey was conducted between August and October 2020 among 970 essential health care workers from 2 health systems in central Texas. The survey captured basic demographic, occupational, and baseline health information including history of mental health disorders. Depression, anxiety, and burnout were assessed with the 8-item Patient Health Questionnaire, 7-item Generalized Anxiety Disorder Scale, and 23-item Burnout Assessment Tool. Questions about clinical contact with patients with suspected or known COVID-19 were also incorporated.Results: Approximately 24% of respondents had moderate or severe anxiety, 14% had moderate or severe depression, and 7% were at high risk for burnout. Statistically significant associations were found between perceived PPE adequacy and the 3 mental health outcomes, while accounting for age, gender, and education. Hours of contact with COVID-19 patients during aerosolizing procedures was positively correlated with measures of anxiety, burnout, and depression after adjustment for age, gender, and occupational role. Perception of PPE adequacy was inversely correlated with measures of depression, anxiety, and burnout among essential members of 2 health care systems, whose roles precluded working remotely during the pandemic.Conclusion: This study highlights the correlations of perceptions of PPE adequacy and contact hours with COVID-19 patients undergoing aerosolizing procedures and employee mental well-being. Future work confirming the findings can help identify ways that systems can support their employees through similarly stressful and demanding events.