RSC Advances
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2018
·Vol. 8
·期 72
·41247-41254
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IF 2.936
Jiong-feng Zhao,Zhe Wang,Fei-long Gao,Jian-ping Lin,Li-rong Yang,Mian-bin Wu
Rhizopus oryzae lipase (ROL) is important because of its extreme sn-1,3-regioselectivity, but it shows poor thermostability, which severely restricts its application. In this work, the thermostability of ROL was greatly enhanced by rational design. First, several sites that may affect the thermostability of ROL were identified by multiple-sequence alignment. The half-lives of mutants V209L and D262G at 55 °C were about 4.38- and 4.2-times those of the wild-type, respectively. Then, a disulfide bond was introduced between positions 190 and 238 based on the prediction of Disulfide by Design 2, which greatly improved the thermostability of the protein. The activity of variant E190C/E238C retained about 58.2% after incubation at 55 °C for 720 min, whereas the half-life of wild type ROL was only about 11.7 min. On the basis of the results obtained by the two methods, we carried out a combined mutation. Quadruple mutant V209L/D262G/E190C/E238C was constructed and the thermostability was improved even further. The half-lives at 55 °C and 65 °C were 102.5- and 20-times those of the wild-type ROL. This improvement in thermostability will give ROL wider industrial applicability, especially in the preparation of structured lipids.
研究领域:
生物化学
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酶工程
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2023
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IF 12.6
Jienan Shen,Zhi Chen,Ruibin Xie,Jingfeng Li,Chunyan Liu,Yaqing He,Xiaopeng Ma,Hui Yang,Zhongjian Xie
Respiratory viruses have long been a major cause of a global pandemic, emphasizing the urgent need for high-sensitivity diagnostic tools. Typical PCR technology can only determine the type of virus in the sample, which is unable to detect different variants of the same virus without costly and time-consuming gene sequencing. Here, we introduce a simple, fully enclosed, and highly integrated microfluidic system based on CRISPR/Cas12a and isothermal amplification techniques (LOC-CRISPR) that can specifically identify multiple common respiratory viruses and their variants. The LOC-CRISPR chip integrates viral nucleic acid extraction, recombinant polymerase amplification, and CRISPR/Cas12a cleavage reaction-based detection, contamination-free detection. In addition, the LOC-CRISPR chip was designed for multiplexed detection (two-sample input and ten-result outputs), which can not only detect the presence of SARS-CoV-2, H 1 N 1 , H 3 N 2 , IVB and HRSV but also differentiate the BA.1, BA.2, and BA.5 variants of SARS-COV-2. For clinical validation, the LOC-CRISPR chip was used to analyze 50 nasopharyngeal swab samples (44 positive and 6 negative) and achieved excellent sensitivity (97.8%) and specificity (100%). This innovative LOC-CRISPR system has the ability to quickly, sensitively, and accurately detect multiple target nucleic acid sequences with single-base mutations, which will further improve the rapid identification and traceability of respiratory viruses infectious diseases.
研究领域:
分子生物学
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医学诊断
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病毒学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2016
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IF 7.476
Weipeng Liu,Minjun Zhu,Hongxing Liu,Jitao Wei,Xiaoming Zhou,Da Xing
Searching for a strategy to enhance the efficiency of nucleic acid amplification and achieve exquisite discrimination of nucleic acids at the single-base level for biological detection has become an exciting research direction in recent years. Here, we have developed a simple and universal primer design strategy which produces a fascinating effect on isothermal strand displacement amplification (iSDA). We refer to the resultant primer as “invading stacking primer (IS-Primer)” which is based on contiguous stacking hybridization and toehold-mediated exchange reaction and function by merely changing the hybridization location of the primer. Using the IS-Primer, the sensitivity in detecting the target miR-21 is improved approximately five fold compared with the traditional iSDA reaction. It was further demonstrated that the IS-Primer acts as an invading strand to initiate branch migration which can increase the efficiency of the untwisting of the hairpin probe. This effect is equivalent to reducing the free energy of the stem, and the technique shows superior selectivity for single-base mismatches. By demonstrating the enhanced effect of the IS-Primer in the iSDA reaction, this work may provide a potentially new avenue for developing more sensitive and selective nucleic acids assays.
研究领域:
分子生物学
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核酸化学
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生物技术
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DOI
PubMed
高影响因子
CHROMATOGRAPHIA
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2022
·Vol. 85
·期 3
·221-231
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IF 2.213
Sun Zhiping,He Lingli,Yang Qingqing,Zhang Haizhi,Xu Weiren,Qin Xinguang,Liu Gang,Hu Zhongze,Zhang Luyong,Liu Changxiao
The influence of genetic polymorphism of metabolic enzymes on drug–drug interactions (DDI) should be thoroughly investigated owing to its remarkable effect on therapeutic treatments that are futile. Here, different from earlier articles focused on various CYP subfamilies and their isoforms, the effect of genetic polymorphs of a particular isoform, CYP2C9, was comprehensively studied. Using diclofenac as probe substrate, the influence of three CYP2C9 variants (CYP2C9*1, *2 and *3) on DDI was conducted from the measurement of inhibitory ability of six drugs towards three variants. A modified LC–MS/MS method according to former report was constructed for the determination of 4ʹ-hydroxydiclofenac in CYP2C9 enzyme incubation system and validated for accuracy, precision, linearity range within the acceptance criteria for regulatory guidelines. After selecting appropriate incubation time and enzyme concentration, the kinetic parameters of three CYP2C9 variants towards diclofenac were examined and half inhibitory concentrations (IC 50 ) of six drugs towards three CYP2C9 variants were determined. IC 50 of paroxetine and losartan towards CYP2C9*2 were almost threefold higher and 2.5-fold lower than that towards CYP2C9*1, respectively. IC 50 of glibenclamide towards CYP2C9*3 was twofold more than that towards CYP2C9*1. Our results could offer effective guidelines for co-administration of these six drugs with various CYP2C9 substrates in individuals carrying variant CYP2C9 alleles, also broaden the application area of LC–MS/MS.
研究领域:
药理学
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临床医学
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分子生物学
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产品关联
DOI
高影响因子
Frontiers in Endocrinology
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2020
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IF 3.644
Ji Huimin,Li Ying,Liu Zhao,Tang Min,Zou Lihui,Su Fei,Zhang Yaqun,Zhang Junhua,Li Hexin,Li Lin,Ai Bin,Ma Jie,Wang Lunan,Liu Ming,Xiao Fei
Although the rapid development of high-throughput sequencing has led to the identification of a large number of truncated or mutated steroid hormone receptor (SHR) variants, their clinical relevance remains to be defined. A platform for functional analysis of these SHR variants in cells would be instrumental for better assessing their impact on normal physiology and SHR-associated diseases. Here we have developed a new reporter system that allows rapid and accurate assessment of the transcriptional activity of SHR variants in cells. The reporter is a single construct containing a firefly luciferase reporter gene, whose expression is under the control of a promoter with multiple steroid hormone responsive elements, and a Renilla luciferase reporter gene, that is constitutively expressed under the control of an internal ribosome entry site (IRES) and is not regulated by steroid hormones. The corresponding SHR (wildtype or mutant/variant) is also expressed from the same construct. Using this improved reporter system, we revealed a large spectrum of transactivation activities within a set of previously identified mutations and variations of the androgen receptor (AR), the estrogen receptor α (ERα) and the glucocorticoid receptor (GR). This novel reporter system enables functional analysis of SHR mutants and variants in physiological and pathological settings, offering valuable preclinical, or diagnostic information for the understanding and treatment of associated diseases.
研究领域:
分子生物学
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内分泌学
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遗传学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
Clinical and Molecular Hepatology
·
2024
·Vol. 30
·期 4
·863
·
IF 14
Baokai Sun,Xiaoqian Ding,Jie Tan,Jie Zhang,Xueru Chu,Shuimi Zhang,Shousheng Liu,Zhenzhen Zhao,Shiying Xuan,Yongning Xin,Likun Zhuang
Backgrounds/Aims Transmembrane 6 superfamily member 2 (TM6SF2) E167K variant is closely associated with the occurrence and development of metabolic dysfunction-associated steatotic liver disease (MASLD). However, the role and mechanism of TM6SF2 E167K variant during MASLD progression are not yet fully understood. Methods The Tm6sf2 167K knock-in (KI) mice were subjected to high-fat diet (HFD). Hepatic lipid levels of Tm6sf2 167K KI mice were detected by lipidomics analysis. Thin-layer chromatography (TLC) was used to measure the newly synthesized triglyceride (TG) and phosphatidylcholine (PC). Results The TM6SF2 E167K variant significantly aggravated hepatic steatosis and injury in HFD-induced mice. Decreased polyunsaturated PC level and increased polyunsaturated TG level were found in liver tissue of HFD-induced Tm6sf2 167K KI mice. Mechanistic studies demonstrated that the TM6SF2 E167K variant increased the interaction between TM6SF2 and PNPLA3, and impaired PNPLA3-mediated transfer of polyunsaturated fatty acids (PUFAs) from TG to PC. The TM6SF2 E167K variant increased the level of fatty acid-induced malondialdehyde and reactive oxygen species, and decreased fatty acid-downregulated cell membrane fluidity. Additionally, the TM6SF2 E167K variant decreased the level of hepatic PC containing C18:3, and dietary supplementation of PC containing C18:3 significantly attenuated the TM6SF2 E167K-induced hepatic steatosis and injury in HFD-fed mice. Conclusions The TM6SF2 E167K variant could promote its interaction with PNPLA3 and inhibit PNPLA3-mediated transfer of PUFAs from TG to PC, resulting in the hepatic steatosis and injury during MASLD progression. PC containing C18:3 could act as a potential therapeutic supplement for MASLD patients carrying the TM6SF2 E167K variant.
研究领域:
肝病学
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分子生物学
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代谢
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脂质代谢
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遗传学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）