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Abstract Background and Objective: Increased antibiotic resistant strains and inadequacy of current vaccines against pneumococcal infections necessitate the study of novel protein antigens. It seems that minor autolysin of Streptococcus pneumoniae may have antigenicity. Thus, we aimed at cloning its gene for the first time. Material and Methods: After DNA extraction of Streptococcus pneumoniae (ATCC 49619), Specific primers were designed for amplifying minor autolysin gene fragment, using PCR. The purified gene fragment was inserted into pET21a vector and was transformed into bacterial competent cells by heat shock technique. The presence of gene and absence of mutation in the recombinant vector were checked out with sequencing and enzymatic digestion methods. The gene sequence was finally analyzed by bioinformatic tools. Results: The gene of minor autolysin was cloned successfully and the result of enzymatic digestion was the indication of complete isolation of this gen from plasmid. . Bioinformatics studies revealed that the mature protein was lacking signal peptide and the gene encoded 318 amino acids with a molecular weight of 36.4 kDa. Conclusion: The presentation and characterization of novel antigens such as minor autolysin could help us with finding new approaches for preventing and controlling pneumococcal infection. Keywords: Streptococcus Pneumoniae, Minor Autolysin, Cloning

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Introduction: DNA Glycation damages DNA by inducing breaks of strands, mutations, and finally changes in gene expression, which is assumed as a main factor in pathogenesis of diabetes and its complications. Therefore, antiglycation agents have been focused recently for preventing and alleviating diabetes complications. According to the reported antidiabetic effects of Artemisia sieberi (A. sieberi) leaves extract, this study was aimed to determine the effect of ethanoic extract of A. sieberi on glucose-mediated DNA glycation for the first time.

Methods: DNA incubated with glucose in the presence or absence of A. sieberi for 4 weeks. The inhibitory or fascilitatory effects of A. sieberi on DNA structural changes were studied by various techniques. These techniques were included UV–Vis, fluorescence spectroscopy, circular dichroism (CD) and agarose gel electrophoresis.
Results: The findings of UV–Vis and fluorescence spectroscopy showed that A. sieberi decreased the DNA-AGE (advanced glycation end products) formation. Based on the CD and agarose gel electrophoresis results, the structural changes of glycated DNA was decreased in the presence of A. sieberi.