• 제목/요약/키워드: ribonuclease

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進化의 分子論的 觀察

  • 한국동물학회
    • 한국동물학회지
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    • 제11권4호
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    • pp.124-142
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    • 1968
  • 原始地球에서 起源된 生命이 分化를 거듭하여 生物이 起源했고 이어서 種의 起源이 있었는데 地球水圈에 存在했던 가지 각색의 原始形態의 生物도 이미 現在와 같은 重要한 生物的 特徵을 지니고 있었다는 事實이 分子生物學的 硏究로도 알려지고 있다. 특히 蛋白質이나 peptide의 아미노酸 序列에 있어서 機能이 全혀 틀리면서 몇 개의 아미노酸만이 바꿔졌든가 또 아미노酸 사슬이 添加됐든가 喪失한듯한 相同的 構造가 알려지고 있는데 이는 vasopressin 과 oxytosin, melanotropic hormone 과 adrenocorticotropin 등의 hormone에서 쉽게 볼수 있다. 또 ribonuclease, insulin, cytochrmoe 등에서는 活性中心이 아닌 部分의 種的變異를 찾아볼 수 있다.

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Gibbrellic Acid와 Abscisic Acid가 보리 초엽(?葉)의 핵산(核酸) 및 핵산분해효소(核酸分解酵素)에 미치는 영향(影響) (The Effect of Gibbrellic Acid and Abscisic Acid on Ribonucleic Acid and Ribonuclease in Barley Coleoptiles)

  • 서용택
    • Applied Biological Chemistry
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    • 제20권2호
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    • pp.242-246
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    • 1977
  • 보리(Hordeum vulgare cultivar Sedohadaka)초엽에 $1{\times}10^{-5}M$ Gibbrellic acid 및 $1{\times}10^{-5}M$ Abscisic acid를 처리(處理)하여 RNase활성(活性)의 경시적(經時的) 소장(消長)을 무처리구(無處理區)와 비교(比較)하고, 핵산(核酸)의 형태(形態)를 관찰하였으며 그 결과(結果)를 요약(要約)하면 다음과 같다. 1) GA는 RNase의 활성(活性)을 억제(抑制)시키는 반면(反面)ABA는 촉진(促進)시켰다. 2) 무처리구(無處理區)에서 정상적인 식물(植物)에 비(比)하여 r-RNA의 비(比)가 낮고 r-RNA의 비(比)가 높았는데 이것은 배양(培養)중 RNase의 작용(作用)에 의한 것 같다. 3) GA는 r-RNA의 분해(分解)를 완화시켰으나 ABA는 촉진(促進)시켰는데 이것은 RNase의 활성(活性)과 관계된 것 같다. 4) GA는 DNA-RNA 복합체(複合體)의 합성(合成)을 촉진(促進)시켰으나 ABA는 이를 억제시켰다. 5) ABA에 의한 s-RNA의 증가(增加)는 r-RNA의 분해산물(分解産物) 때문이라 생각된다.

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Biocomputational Characterization and Evolutionary Analysis of Bubaline Dicer1 Enzyme

  • Singh, Jasdeep;Mukhopadhyay, Chandra Sekhar;Arora, Jaspreet Singh;Kaur, Simarjeet
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권6호
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    • pp.876-887
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    • 2015
  • Dicer, an ribonuclease type III type endonuclease, is the key enzyme involved in biogenesis of microRNAs (miRNAs) and small interfering RNAs (siRNAs), and thus plays a critical role in RNA interference through post transcriptional regulation of gene expression. This enzyme has not been well studied in the Indian water buffalo, an important species known for disease resistance and high milk production. In this study, the primary coding sequence (5,778 bp) of bubaline dicer (GenBank: AB969677.1) was determined and the bubaline Dicer1 biocomputationally characterized to determine the phylogenetic signature among higher eukaryotes. The evolutionary tree revealed that all the transcript variants of Dicer1 belonging to a specific species were within the same node and the sequences belonging to primates, rodents and lagomorphs, avians and reptiles formed independent clusters. The bubaline dicer1 is closely related to that of cattle and other ruminants and significantly divergent from dicer of lower species such as tapeworm, sea urchin and fruit fly. Evolutionary divergence analysis conducted using MEGA6 software indicated that dicer has undergone purifying selection over the time. Seventeen divergent sequences, representing each of the families/taxa were selected to study the specific regions of positive vis-$\grave{a}$-vis negative selection using different models like single likelihood ancestor counting, fixed effects likelihood, and random effects likelihood of Datamonkey server. Comparative analysis of the domain structure revealed that Dicer1 is conserved across mammalian species while variation both in terms of length of Dicer enzyme and presence or absence of domain is evident in the lower organisms.

A study of ribonuclease activity in venom of vietnam cobra

  • Nguyen, Thiet Van;Osipov, A.V.
    • Journal of Animal Science and Technology
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    • 제59권9호
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    • pp.20.1-20.9
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    • 2017
  • Background: Ribonuclease (RNase) is one of the few toxic proteins that are present constantly in snake venoms of all types. However, to date this RNase is still poorly studied in comparison not only with other toxic proteins of snake venom, but also with the enzymes of RNase group. The objective of this paper was to investigate some properties of RNase from venom of Vietnam cobra Naja atra. Methods: Kinetic methods and gel filtration chromatography were used to investigate RNase from venom of Vietnam cobra. Results: RNase from venom of Vietnam cobra Naja atra has some characteristic properties. This RNase is a thermostable enzyme and has high conformational stability. This is the only acidic enzyme of the RNase A superfamily exhibiting a high catalytic activity in the pH range of 1-4, with $pH_{opt}=2.58{\pm}0.35$. Its activity is considerably reduced with increasing ionic strength of reaction mixture. Venom proteins are separated by gel filtration into four peaks with ribonucleolytic activity, which is abnormally distributed among the isoforms: only a small part of the RNase activity is present in fractions of proteins with molecular weights of 12-15 kDa and more than 30 kDa, but most of the enzyme activity is detected in fractions of polypeptides, having molecular weights of less than 9 kDa, that is unexpected. Conclusions: RNase from the venom of Vietnam cobra is a unique member of RNase A superfamily according to its acidic optimum pH ($pH_{opt}=2.58{\pm}0.35$) and extremely low molecular weights of its major isoforms (approximately 8.95 kDa for RNase III and 5.93 kDa for RNase IV).

Presence of Diverse Sugarcane Bacilliform Viruses Infecting Sugarcane in China Revealed by Pairwise Sequence Comparisons and Phylogenetic Analysis

  • Ahmad, Kashif;Sun, Sheng-Ren;Chen, Jun-Lu;Huang, Mei-Ting;Fu, Hua-Ying;Gao, San-Ji
    • The Plant Pathology Journal
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    • 제35권1호
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    • pp.41-50
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    • 2019
  • Sugarcane bacilliform viruses (SCBV), which belong to the genus Badnavirus, family Caulimoviridae, are an important DNA virus complex that infects sugarcane. To explore the genetic diversity of the sugarcane-infecting badnavirus complex in China, we tested 392 sugarcane leaf samples collected from Fujian, Yunnan, and Hainan provinces for the occurrence of SCBV by polymerase chain reaction (PCR) assays using published primers SCBV-F and SCBV-R that target the reverse transcriptase/ribonuclease H (RT/RNase H) regions of the viral genome. A total of 111 PCR-amplified fragments (726 bp) from 63 SCBV-positive samples were cloned and sequenced. A neighbor-joining phylogenetic tree was constructed based on the SCBV sequences from this study and 34 published sequences representing 18 different phylogroups or genotypes (SCBV-A to -R). All SCBV-tested isolates could be classified into 20 SCBV phylogenetic groups from SCBV-A to -T. Of nine SCBV phylogroups reported in this study, two novel phylogroups, SCBV-S and SCBV-T, that share 90.0-93.2% sequence identity and show 0.07-0.11 genetic distance with each other in the RT/RNase H region, are proposed. SCBV-S had 57.6-92.2% sequence identity and 0.09-0.66 genetic distance, while SCBV-T had 58.4-90.0% sequence identity and 0.11-0.63 genetic distance compared with the published SCBV phylogroups. Additionally, two other Badnavirus species, Sugarcane bacilliform MO virus (SCBMOV) and Sugarcane bacilliform IM virus (SCBIMV), which originally clustered in phylogenetic groups SCBV-E and SCBV-F, respectively, are first reported in China. Our findings will help to understand the level of genetic heterogeneity present in the complex of Badnavirus species that infect sugarcane.

Influence of Refeeding of Protein, Carbohydrate and Fat on Hepatic Insulin-Like Growth Factor-I mRNA Level in Fasted Chicks

  • Kita, K.;Hangsanet, K.;Okumura, J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권3호
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    • pp.245-248
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    • 1998
  • The influence of refeeding either protein, carbohydrate or fat on hepatic insulin-like growth factor-I (IGF-I) mRNA level in chicks which had been fasted for 2 days was examined. The hepatic IGF-I mRNA was measured by ribonuclease protection assay. Fasting reduced hepatic IGF-I mRNA levels to less than half of those in the fed control. When chicks were refed either a control, protein or carbohydrate diet, IGF-I mRNA levels significantly increased to those in the fed control until 2 hours of refeeding. Refeeding of fat did not alter hepatic IGF-I mRNA levels. The significant correlation between liver weight and hepatic IGF-I gene expression suggests that when chicks are refed after 2-d fasting, the acute increase in hepatic IGF-I gene expression brought about after refeeding may be partly regulated by the increase in liver protein metabolism.

Development of Anti-viral Agents from Natural Sources

  • Hattori, Masao
    • Plant Resources
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    • 제4권3호
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    • pp.192-195
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    • 2001
  • Human immunodeficiency virus (HIV), the causative agent of AIDS, still continues to spread rapidly in the world population, especially in Africa and Southeast Asia. At present, two kinds of therapeutic approaches are used for treatment of AIDS. One is to target HIV reverse transcriptase, which is responsible for the viral genome transcription. The other is to inhibit HIV pretense PR, which is essential for the processing of viral proteins. Drug combinations based on these approaches can reduce the blood virus to an undetectable level. However, a small amount of virus may lurk inside the immune cells in a dormant state. Another major obstacle of long-term treatment of the disease is remarkable mutation in HIV. Most of the clinical chemotherapeutic agents have one or more of these problems. High cost and harmful side-effects further reduced the desirability of these drugs. In the course our studies on development of anti-HIV agents from natural products, we investigated various crude drugs for their inhibitory activity against HIV-induced cytopathic effects (CPE) in culture cells, HIV-pretense (PR), HIV-reverse transcriptase (RT) including ribonuclease H (RNase H), and HIV integrase (INT). In the present paper, some inhibitory substances relating to the development of anti-HIV agents are reported.

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Adverse Interfacial Effects upon Protein Stability: Implications in Developing Emulsion-Based Protein Delivery Systems

  • Sah, Hongkee
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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    • pp.146-148
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    • 2001
  • The objective of this study was to investigate the behavior of ribonuclease A (RNase) at the water/methylene chloride interface. It was aimed at better understanding the denaturation of proteins upon emulsification. RNase was vulnerable to the interface-induced aggregation reactions that led to formation of water-insoluble aggregates upon emulsification. Biochemical analyses demonstrated that intermolecular covalent linkages might have been involved in the aggregation reactions. The protein instability observed with emulsification was traced to consequences of protein adsorption and conformational rearrangements at the interface. These results indicated that emulsifying aqueous protein solutions in organic solvents should be handled with care, since emulsification could bring denaturation and aggregation to proteins.

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Chmical Shift Variation of Bovine Angiogenin Upon Binding with Phosphate ions

  • Baek, Sun-Hee;Kang, Dong-Il;Lee, Jee-Young;Shin, Hang-Cheol;Kim, Yang-Mee
    • 한국자기공명학회논문지
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    • 제10권2호
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    • pp.155-162
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    • 2006
  • Angiogenin is unique among angiogenic molecules in that it is a member of the pancreatic ribonuclease superfamily and, in fact, is a ribonucleolytic enzyme. Its enzymatic activity is extremely weak compared to that of the digestive RNases but is critical for its capacity to induce neovascularization. In this study, we completed the backbone resonance assignment of bovine angiogenin using triple resonance NMR experiments of $^{15}N\;and/or\;^{13}C$ isotope labeled protein and investigated the chemical shift variation upon binding with inhibitor phosphate ion and determine the phosphate binding site.

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