Differential methods of scanning micro-calorimetry and UV spectrophotometry were used for understanding the interaction of natural anti-tumour antibiotic actinomycin D with cluster sites of native and fragmented DNA during thermal melting. At low (micro-molar) concentrations, the actinomycin molecules penetrate into unwound regions of DNA, but not into the double helix. Moreover, they stabilize the fragmented DNA and increase a total melting point. Actinomycin D interacts with fractions of native DNA even at very low concentrations (at the antibiotic/nucleotide ratio of 1:868) and stabilizes the most loose clusters. At high concentrations, it destabilizes the double helix.
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http://dx.doi.org/10.1093/jb/mvr019 | DOI Listing |
CRISPR J
January 2025
Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA.
Bacteria and archaea acquire resistance to genetic parasites by preferentially integrating short fragments of foreign DNA at one end of a Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR). "Leader" DNA upstream of CRISPR loci regulates transcription and foreign DNA integration into the CRISPR. Here, we analyze 37,477 CRISPRs from 39,277 bacterial and 556 archaeal genomes to identify conserved sequence motifs in CRISPR leaders.
View Article and Find Full Text PDFVet Med Sci
January 2025
Department of Medical Biology, Faculty of Medicine, Dicle University, Diyarbakir, Turkey.
Background: Chemotherapy drugs may lead to hepatic injury, which is considered one of the limitations of these drugs.
Objectives: The aim of this study was to evaluate the effect of quercetin (QUE) on M1/M2 macrophage polarization and hepatoprotective effect in cyclophosphamide (CTX)-induced liver toxicity.
Methods: Twenty-four mice were divided into four groups (Control, QUE, CTX, CTX + QUE).
Yi Chuan
January 2025
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430078, China.
It has been more than 40 years since the beginning of exploring the genetic composition of ancient organisms from the perspective of ancient DNA. In the recent 20 years, with the development and application of high-throughput sequencing technology platforms and the improved efficiency of retrieving highly fragmented DNA molecules, ancient DNA research moved forward to a brand-new era of deep-time paleogenomics. It not only solved many controversial phylogenetic problems, enriched the migration and evolution details of various organisms including humans, but also launched exploration of the molecular responses to climate changes in terms of "whole genomic-big data-multi-species" level.
View Article and Find Full Text PDFCurr Med Chem
January 2025
School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, China.
Branched-chain amino acids (BCAAs) are essential amino acids for humans and play an indispensable role in many physiological and pathological processes. Branched-chain amino acid aminotransferase (BCAT) is a key enzyme that catalyzes the metabolism of BCAAs. BCAT is upregulated in many cancers and implicated in the development and progress of some other diseases, such as metabolic and neurological diseases; and therefore, targeting BCAT might be a potential therapeutic approach for these diseases.
View Article and Find Full Text PDFReprod Sci
January 2025
Department of Biology, Faculty of Science, University of Qom, Qom, 3716146611, Iran.
Fluoxetine is used in the management of depression, anxiety and other mood disorders by increasing serotonin levels in the brain and can cause sexual side effects by changing the homeostasis of sex hormones and increasing oxidative stress. Since many men who take fluoxetine are of reproductive age and sperm are exposed to fluoxetine for a considerable time, this study aimed to examine the in vitro effects of fluoxetine on human sperm biochemical markers and sperm parameters. Semen samples from 30 fertile men were divided into three groups: a positive control group, a negative control group and a fluoxetine-treated group.
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