RESUMO
INTRODUCTION: This study aims to assess the quality and reliability of the disease information available on YouTube (www.youtube.com) about "heart attacks" or myocardial infarctions, using a Global Quality Score (GQS) for quality, a DISCERN score for reliability, and a Video Power Index (VPI) for popularity. METHODOLOGY: In this cross-sectional observational study, the YouTube videos were analyzed in terms of the type of uploader, content, and other factors. The GQS, DISCERN score, and Video Power Index (VPI) were utilized to assess the quality, reliability, and popularity of the information, respectively. RESULTS: The majority of the videos (78.44%) were uploaded over a year ago. Only 33.34% and 7.84% were uploaded by doctors and healthcare organizations, respectively. Around 72.55% of the videos contained information about symptoms, 66.67% discussed the causes, 52.94% covered treatment, and 47.06% focused on prevention. Additionally, 41.18% provided details on investigations, while only 19.61% touched upon mortality. Patient-created videos accounted for 19.61% of the content, and 15.69% of the videos included promotional material. CONCLUSION: The main outcome of our study indicates that the YouTube videos examined regarding myocardial infarctions exhibit high-quality content, as supported by a higher average GQS score. The consistent quality of information discovered in our study suggests that YouTube can serve as an additional platform for sharing knowledge and educating individuals about this important health condition. By raising awareness and delivering accurate information, these videos can help in early detection, prevention, and better outcomes for individuals who are at risk of experiencing a myocardial infarction.
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The PE and PPE protein family are unique to mycobacteria. Though the complete genome sequences for over 500 M. tuberculosis strains and mycobacterial species are available, few PE and PPE proteins have been structurally and functionally characterized. We have therefore used bioinformatics tools to characterize the structure and function of these proteins. We selected representative members of the PE and PPE protein family by phylogeny analysis and using structure-based sequence annotation identified ten well-characterized protein domains of known function. Some of these domains were observed to be common to all mycobacterial species and some were species specific.
Assuntos
Proteínas de Bactérias/genética , Genoma Bacteriano , Mycobacterium tuberculosis/genética , Mycobacterium/genética , Fatores de Virulência/genética , Motivos de Aminoácidos , Proteínas de Bactérias/química , Biologia Computacional , Modelos Moleculares , Dados de Sequência Molecular , Família Multigênica , Mycobacterium/classificação , Mycobacterium tuberculosis/classificação , Filogenia , Estrutura Terciária de Proteína , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Fatores de Virulência/químicaRESUMO
The PE and PPE multigene families, first discovered during the sequencing of M. tuberculosis H37Rv genome are responsible for antigenic variation and have been shown to induce increased humoral and cell mediated immune response in the host. Using the bioinformatics tools, we had earlier reported that the 225 amino acid residue PE-PPE domain (Pfam: PF08237) common to some PE and PPE proteins has a "serine α/ß hydrolase" fold and conserved Ser, Asp and His catalytic triad characteristic of lipase, esterase and cutinase activities. In order to prove experimentally that PE-PPE domain is indeed a serine hydrolase, we have cloned the full-length Rv1430 and its PE-PPE domain into pET-28a vector, expressed the proteins in E. coli and purified to homogeneity. The activity assays of both purified proteins were carried out using p-nitrophenyl esters of aliphatic carboxylic acids with varying chain length (C2-C16) to study the substrate specificity. To characterize the active site of the PE-PPE domain, we mutated the Ser199 to Ala. The activity of the protein in the presence of serine protease inhibitor- PMSF and the mutant protein were measured. Our results reveal that Rv1430 and its PE-PPE domain possess esterase activity and hydrolyse short to medium chain fatty acid esters with the highest specific activity for pNPC6 at 37°C, 38°C and pH 7.0, 8.0. The details of this work and the observed results are reported in this manuscript.
Assuntos
Proteínas de Bactérias/genética , Esterases/genética , Família Multigênica/genética , Mycobacterium tuberculosis/enzimologia , Serina Endopeptidases/genética , Western Blotting , Domínio Catalítico/genética , Dicroísmo Circular , Clonagem Molecular , Biologia Computacional , Primers do DNA/genética , Escherichia coli , Concentração de Íons de Hidrogênio , Mycobacterium tuberculosis/genética , TemperaturaRESUMO
The PE and PPE proteins first reported in the genome sequence of Mycobacterium tuberculosis strain H37Rv are now identified in all mycobacterial species. The PE-PPE domain (Pfam ID: PF08237) is a 225 amino acid residue conserved region located towards the C-terminus of some PE and PPE proteins and hypothetical proteins. Our in-silico sequence analysis revealed that this domain is present in all Mycobacteria, some Rhodococcus and Nocardia farcinica genomes. This domain comprises a pentapeptide sequence motif GxSxG/S at the N-terminus and conserved amino acid residues Ser, Asp and His that constitute a catalytic triad characteristic of lipase, esterase and cutinase activity. The fold prediction and comparative modeling of the 3-D structure of the PE-PPE domain revealed a "serine α/ß hydrolase" structure with a central ß-sheet flanked by α-helices on either side. The structure comprises a lid insertion with a closed structure conformation and has a solvent inaccessible active site. The oxyanion hole that stabilizes the negative charge on the tetrahedral intermediate has been identified. Our findings add to the growing list of serine hydrolases in mycobacterium, which are essential for the maintenance of their impermeable cell wall and virulence. These results provide the directions for the design of experiments to establish the function of PE and PPE proteins.