{"title":"Nanoscale intracellular ultrastructures affected by osmotic pressure using small-angle X-ray scattering","authors":"Masaru Nakada , Junko Kanda , Hironobu Uchiyama , Kazuaki Matsumura","doi":"10.1016/j.bpc.2024.107287","DOIUrl":null,"url":null,"abstract":"<div><p>Although intracellular ultrastructures have typically been studied using microscopic techniques, it is difficult to observe ultrastructures at the submicron scale of living cells due to spatial resolution (fluorescence microscopy) or high vacuum environment (electron microscopy). We investigate the nanometer scale intracellular ultrastructures of living CHO cells in various osmolality using small-angle X-ray scattering (SAXS), and especially the structures of ribosomes, DNA double helix, and plasma membranes <em>in-cell</em> environment are observed. Ribosomes expand and contract in response to osmotic pressure, and the inter-ribosomal correlation occurs under isotonic and hyperosmolality. The DNA double helix is not dependent on the osmotic pressure. Under high osmotic pressure, the plasma membrane folds into form a multilamellar structure with a periodic length of about 6 nm. We also study the ultrastructural changes caused by formaldehyde fixation, freezing and heating.</p></div>","PeriodicalId":8979,"journal":{"name":"Biophysical chemistry","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biophysical chemistry","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0301462224001169","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Although intracellular ultrastructures have typically been studied using microscopic techniques, it is difficult to observe ultrastructures at the submicron scale of living cells due to spatial resolution (fluorescence microscopy) or high vacuum environment (electron microscopy). We investigate the nanometer scale intracellular ultrastructures of living CHO cells in various osmolality using small-angle X-ray scattering (SAXS), and especially the structures of ribosomes, DNA double helix, and plasma membranes in-cell environment are observed. Ribosomes expand and contract in response to osmotic pressure, and the inter-ribosomal correlation occurs under isotonic and hyperosmolality. The DNA double helix is not dependent on the osmotic pressure. Under high osmotic pressure, the plasma membrane folds into form a multilamellar structure with a periodic length of about 6 nm. We also study the ultrastructural changes caused by formaldehyde fixation, freezing and heating.
尽管细胞内超微结构通常采用显微镜技术进行研究,但由于空间分辨率(荧光显微镜)或高真空环境(电子显微镜)的限制,很难观察到活细胞亚微米尺度的超微结构。我们利用小角 X 射线散射(SAXS)研究了活体 CHO 细胞在不同渗透压下的纳米尺度胞内超微结构,尤其是观察了细胞环境中核糖体、DNA 双螺旋和质膜的结构。核糖体随渗透压的变化而膨胀和收缩,在等渗和高渗条件下,核糖体之间发生关联。DNA 双螺旋不依赖于渗透压。在高渗透压下,质膜折叠成周期性长度约为 6 纳米的多层膜结构。我们还研究了甲醛固定、冷冻和加热引起的超微结构变化。
期刊介绍:
Biophysical Chemistry publishes original work and reviews in the areas of chemistry and physics directly impacting biological phenomena. Quantitative analysis of the properties of biological macromolecules, biologically active molecules, macromolecular assemblies and cell components in terms of kinetics, thermodynamics, spatio-temporal organization, NMR and X-ray structural biology, as well as single-molecule detection represent a major focus of the journal. Theoretical and computational treatments of biomacromolecular systems, macromolecular interactions, regulatory control and systems biology are also of interest to the journal.