DNA compaction by alkyltrimethylammonium surfactants at hydrophobized silica surfaces and the effect of the counterion, as well as the hydrocarbon chain length, was investigated by in situ null-ellipsometry. In addition, DNA compaction in the presence of a gemini surfactant, hexyl-alpha,omega-bis(dodecyldimethylammonium bromide), was studied. The type of cationic amphiphile used was found not to have a pronounced effect on the mixed DNA-cationic surfactant adsorbed layer thickness, although the surface concentration excess for the mixed layers seemed to follow the same trend as that for DNA-free surfactant layers. Interestingly, it was also found that the stability of the mixed adsorbed layer largely depends on the cationic surfactant used.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/la0501740 | DOI Listing |
Int J Mol Sci
December 2024
Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA.
In eukaryotic nuclei, DNA is wrapped around an octamer of core histones to form nucleosomes. H1 binds to the linker DNA of nucleosome to form the chromatosome, the next structural unit of chromatin. Structural features on individual chromatosomes contribute to chromatin structure, but not fully characterized.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, Cixi Biomedical Research Institute, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou 325035, China.
Accurate identification of cancer cells under complex physiological environments holds great promise for noninvasive diagnosis and personalized medicine. Herein, we developed dual-aptamer-based DNA logic-gated series lamp probes (Apt-SLP) by coupling a DNA cell-classifier (DCC) with a self-powered signal-amplifier (SSA), enabling rapid and sensitive identification of cancer cells in a blood sample. DCC is endowed with two extended-aptamer based modules for recognizing the two cascade cell membrane receptors and serves as a DNA logic gate to pinpoint a particular and narrow subpopulation of cells from a larger population of similar cells.
View Article and Find Full Text PDFJ Cell Biol
March 2025
Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL) , Heidelberg, Germany.
How cells establish the interphase genome organization after mitosis is incompletely understood. Using quantitative and super-resolution microscopy, we show that the transition from a Condensin to a Cohesin-based genome organization occurs dynamically over 2 h. While a significant fraction of Condensins remains chromatin-bound until early G1, Cohesin-STAG1 and its boundary factor CTCF are rapidly imported into daughter nuclei in telophase, immediately bind chromosomes as individual complexes, and are sufficient to build the first interphase TAD structures.
View Article and Find Full Text PDFJ Chem Phys
January 2025
School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
Eukaryotic DNA is packaged in the cell nucleus into chromatin, composed of arrays of DNA-histone protein octamer complexes, the nucleosomes. Over the past decade, it has become clear that chromatin structure in vivo is not a hierarchy of well-organized folded nucleosome fibers but displays considerable conformational variability and heterogeneity. In vitro and in vivo studies, as well as computational modeling, have revealed that attractive nucleosome-nucleosome interaction with an essential role of nucleosome stacking defines chromatin compaction.
View Article and Find Full Text PDFNat Commun
January 2025
Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, 78712, USA.
Type II CRISPR endonucleases are widely used programmable genome editing tools. Recently, CRISPR-Cas systems with highly compact nucleases have been discovered, including Cas9d (a type II-D nuclease). Here, we report the cryo-EM structures of a Cas9d nuclease (747 amino acids in length) in multiple functional states, revealing a stepwise process of DNA targeting involving a conformational switch in a REC2 domain insertion.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!