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Summary: Due to the enhanced labeling capability of maleimide-based fluorescent probes, lysine-cysteine-lysine (KCK) tags are frequently added to proteins for visualization. In this study, we employed an in vitro single-molecule DNA flow-stretching assay as a sensitive way to assess the impact of the KCK tag on the property of DNA-binding proteins. Using Bacillus subtilis ParB as an example, we show that, although no noticeable changes were detected by in vivo fluorescence imaging and chromatin immunoprecipitation (ChIP) assays, the KCK tag substantially altered ParB’s DNA compaction rates and its response to nucleotide binding and to the presence of the specific sequence (parS) on the DNA. While it is typically assumed that short peptide tags minimally perturb protein function, our results urge researchers to carefully validate the use of tags for protein labeling. Our comprehensive analysis can be expanded and used as a guide to assess the impacts of other tags on DNA-binding proteins in single-molecule assays. Motivation: Single-molecule fluorescence microscopy has been extensively used in modern biology to define the molecular action of proteins. Appending short peptide tags is a common strategy to enhance fluorescence labeling. Here, we evaluate the impact of a commonly used tag, the lysine-cysteine-lysine (KCK) tag, on protein behavior in single-molecule DNA flow-stretching assay, which is a sensitive and versatile method to understand the action of DNA-binding proteins. Our motivation is to provide researchers with an experimental framework to validate fluorescently labeled DNA-binding proteins in single-molecule methods.

O texto se propõe a discutir os desafios e possibilidades de atuação de cinco mulheres regentes que atuam em bandas de música no contexto de Santa Catarina. A pesquisa seguiu os princípios da abordagem qualitativa, com recolha de dados mediante a utilização de questionário de sondagem inicial e entrevista semiestruturada. Foram selecionadas quatro regentes que atuam em bandas de música vinculadas ao Programa de Bandas e Fanfarras e uma regente de banda de música que atua em contexto não educacional. Foi possível observar que ainda existe no estado de Santa Catarina uma baixa representação de mulheres atuando como regentes em bandas de música. As participantes da pesquisa reconhecem que a presença de mulheres como instrumentistas nesses agrupamentos pode contribuir para ampliar o número de mulheres regendo nesse contexto. Para tanto, mencionam a importância da formação de uma rede de apoio entre mulheres, o apoio familiar, a necessidade de cursos de formação continuada e, principalmente, a necessidade de fóruns e debates sobre regência em bandas de música direcionados às mulheres, de modo a ajudar a construir estratégias de superação de dificuldades e do preconceito que ainda se apresenta quando é uma mulher que está à frente de uma banda de música.

The effects of hydroethanolic extract of Yacon leaves (HEYL) on antioxidant, glycemic, and inflammatory biomarkers were tested in diabetic rats. Outcome parameters included glucose, insulin, interleukin-6 (IL-6), and hydrophilic antioxidant capacity (HAC) in serum and IL-6, HAC, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in soleus. The rats (10/group) were divided as follows: C, controls; C + Y, HEYL treated; DM, diabetic controls; and DM + Y, diabetic rats treated with HEYL. Diabetes mellitus was induced by administration of streptozotocin. C + Y and DM + Y groups received 100 mg/kg HEYL daily via gavage for 30 d. Hyperglycemia was improved in the DM + Y versus DM group. Insulin was reduced in DM versus C group. DM rats had higher IL-6 and MDA and lower HAC in the soleus muscle. HEYL treatment decreased IL-6 and MDA and increased HAC in DM rats. DM + Y rats had the highest CAT activity versus the other groups; GPx was higher in C + Y and DM + Y versus their respective controls. The apparent benefit of HEYL may be mediated via improving glucoregulation and ameliorating oxidative stress and inflammation, particularly in diabetic rats.