Enzymes最新文献_第5页

Overview of DNA damage and double-strand breaks. DNA损伤和双链断裂概述。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-10-07 DOI: 10.1016/bs.enz.2022.08.001

Fuyuhiko Tamanoi, Kenichi Yoshikawa

引用次数: 0

Damages of DNA in tritiated water. 氚化水中DNA的损伤。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-10-05 DOI: 10.1016/bs.enz.2022.08.009

Yuji Hatano, Hiroaki Nakamura, Susumu Fujiwara, Seiki Saito, Takahiro Kenmotsu

{"title":"Damages of DNA in tritiated water.","authors":"Yuji Hatano, Hiroaki Nakamura, Susumu Fujiwara, Seiki Saito, Takahiro Kenmotsu","doi":"10.1016/bs.enz.2022.08.009","DOIUrl":"https://doi.org/10.1016/bs.enz.2022.08.009","url":null,"abstract":"Tritium is a radioisotope of hydrogen emitting low energy β-rays in disintegration to 3He. DNA molecules are damaged mainly by β-ray irradiation, and additional damages can be induced by break of chemical bond by nuclear transmutation to inert 3He. Deep knowledges of the mechanisms underlying DNA damages lead to better understanding of biological effects of tritium. This chapter reviews recent experimental and computer simulation activities on quantitative evaluation of damage rates by β-ray irradiation and nuclear transmutation. The rate of DNA double-strand breaks in tritiated water has been examined using a single molecule observation method. The effects of β-ray irradiation were not noticeable at the level of tritium concentration of ∼kBq/cm3, while the irradiation effects were clear at tritium concentrations of ∼MBq/cm3. The factors affecting on the DSB rate are discussed. A new image processing method for the automatic measurement of DNA length using OpenCV and deep learning is also introduced. The effects of tritium transmutation on hydrogen bonds acting between the two main strands of DNA have been examined using molecular dynamics simulations. The study showed that the collapsing of DNA structure by the transmutation can be quantitatively evaluated using the root mean square deviation of atomic positions.","PeriodicalId":39097,"journal":{"name":"Enzymes","volume":"51 ","pages":"131-152"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40682355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical force induced DNA double-strand breaks: Ultrasound. 机械力诱导DNA双链断裂:超声。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-09-27 DOI: 10.1016/bs.enz.2022.08.004

Yue Ma, Iwaki Akiyama

引用次数: 0

Auger electrons and DNA double-strand breaks studied by using iodine-containing chemicals. 利用含碘化学物质研究俄歇电子和DNA双链断裂。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-09-27 DOI: 10.1016/bs.enz.2022.08.007

Yuya Higashi, Yue Ma, Kotaro Matsumoto, Ayumi Shiro, Hiroyuki Saitoh, Tetsuya Kawachi, Fuyuhiko Tamanoi

{"title":"Auger electrons and DNA double-strand breaks studied by using iodine-containing chemicals.","authors":"Yuya Higashi, Yue Ma, Kotaro Matsumoto, Ayumi Shiro, Hiroyuki Saitoh, Tetsuya Kawachi, Fuyuhiko Tamanoi","doi":"10.1016/bs.enz.2022.08.007","DOIUrl":"https://doi.org/10.1016/bs.enz.2022.08.007","url":null,"abstract":"Irradiation of high Z elements such as iodine, gold, gadolinium with monochromatic X-rays causes photoelectric effects that include the release of Auger electrons. Decay of radioactive iodine such as I-123 and I-125 also results in multiple events and some involve the generation of Auger electrons. These electrons have low energy and travel only a short distance but have a strong effect on DNA damage including the generation of double-strand breaks. In this chapter, we focus on iodine and discuss various studies that used iodine-containing chemicals to generate Auger electrons and cause DNA double-strand breaks. First, DNA synthesis precursors containing iodine were used to place iodine on DNA. DNA binding dyes such as iodine Hoechst were investigated for Auger electron generation and DNA breaks. More recently, iodine containing nanoparticles were developed. We describe our study using tumor spheroids loaded with iodine nanoparticles and synchrotron-generated monochromatic X-rays. This study led to the demonstration that an optimum effect on DNA double-strand break formation is observed with a 33.2keV X-ray which is just above the K-edge energy of iodine.","PeriodicalId":39097,"journal":{"name":"Enzymes","volume":"51 ","pages":"101-115"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40667370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chromatin organization and DNA damage. 染色质组织和DNA损伤。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-09-27 DOI: 10.1016/bs.enz.2022.08.003

Katsuhiko Minami, Shiori Iida, Kazuhiro Maeshima

{"title":"Chromatin organization and DNA damage.","authors":"Katsuhiko Minami, Shiori Iida, Kazuhiro Maeshima","doi":"10.1016/bs.enz.2022.08.003","DOIUrl":"https://doi.org/10.1016/bs.enz.2022.08.003","url":null,"abstract":"Genomic DNA is organized three-dimensionally in the nucleus as chromatin. Recent accumulating evidence has demonstrated that chromatin organizes into numerous dynamic domains in higher eukaryotic cells, which act as functional units of the genome. These compacted domains facilitate DNA replication and gene regulation. Undamaged chromatin is critical for healthy cells to function and divide. However, the cellular genome is constantly threatened by many sources of DNA damage (e.g., radiation). How do cells maintain their genome integrity when subjected to DNA damage? This chapter describes how the compact state of chromatin safeguards the genome from radiation damage and chemical attacks. Together with recent genomics data, our finding suggests that DNA compaction, such as chromatin domain formation, plays a critical role in maintaining genome integrity. But does the formation of such domains limit DNA accessibility inside the domain and hinder the recruitment of repair machinery to the damaged site(s) during DNA repair? To approach this issue, we first describe a sensitive imaging method to detect changes in chromatin states in living cells (single-nucleosome imaging/tracking). We then use this method to explain how cells can overcome potential recruiting difficulties; cells can decompact chromatin domains following DNA damage and temporarily increase chromatin motion (∼DNA accessibility) to perform efficient DNA repair. We also speculate on how chromatin compaction affects DNA damage-resistance in the clinical setting.","PeriodicalId":39097,"journal":{"name":"Enzymes","volume":"51 ","pages":"29-51"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40682356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Quantitative evaluation of DNA double-strand breaks (DSBs) through single-molecule observation. 通过单分子观察定量评价DNA双链断裂(DSBs)。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-10-03 DOI: 10.1016/bs.enz.2022.08.002

Kenichi Yoshikawa

引用次数: 0

Core level ionization or excitation and Auger relaxation induce clustered DNA damage. 核能级电离或激发和俄歇弛豫诱导聚集性DNA损伤。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-10-07 DOI: 10.1016/bs.enz.2022.08.006

Akinari Yokoya, Yui Obata

{"title":"Core level ionization or excitation and Auger relaxation induce clustered DNA damage.","authors":"Akinari Yokoya, Yui Obata","doi":"10.1016/bs.enz.2022.08.006","DOIUrl":"https://doi.org/10.1016/bs.enz.2022.08.006","url":null,"abstract":"Ionizing radiation causes various types of DNA damage, such as single- (SSBs) and double-strand breaks (DSBs), nucleobase lesions, abasic sites (AP sites), and cross-linking between complementary strands of DNA or DNA and proteins. DSBs are among the most harmful type of DNA damage, inducing serious genetic effects such as cell lethality and mutation. Nucleobase lesions and AP sites, on the other hand, may be less deleterious and are promptly repaired by base excision repair (BER) pathways. Recently, biochemical approaches to quantify nucleobase lesions and AP sites have revealed certain types of non-strand break lesions as harmful DNA damage, called clustered DNA damage. Such clusters can retard nucleobase excision repair enzymes, and can sometimes be converted to DSBs by BER catalysis. This unique character of clustered DNA damage strongly depends on the spatial density of ionization or excitation events occurring at the track end of initial radiation or low energy secondary electrons. In particular, the photoelectric effect of elements comprising biological molecules, followed by emission of Auger electrons, are key factors in determining the future fate of each clustered damage site. This chapter describes biological studies of clustered nucleobase lesions with SSBs or AP sites, and mechanistical studies on core level excitation and Auger relaxation giving rise to clustered DNA damage.","PeriodicalId":39097,"journal":{"name":"Enzymes","volume":"51 ","pages":"79-100"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40682360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The enzymes first edition. 酶的第一版。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-11-07 DOI: 10.1016/bs.enz.2022.10.003

Fuyuhiko Tamanoi

引用次数: 0

The enzymes second edition part 1. 酶学第二版第1部分。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-11-07 DOI: 10.1016/bs.enz.2022.10.004

Fuyuhiko Tamanoi

引用次数: 0

Carbon ion radiation and clustered DNA double-strand breaks. 碳离子辐射和DNA双链断裂。

Enzymes Pub Date : 2022-01-01 Epub Date: 2022-09-27 DOI: 10.1016/bs.enz.2022.08.008

Atsushi Shibata

引用次数: 0