期刊文献+
共找到554篇文章
< 1 2 28 >
每页显示 20 50 100
A reduced computational load protein coding predictor using equivalent amino acid sequence of DNA string with period-3 based time and frequency domain analysis 被引量:1
1
作者 Jayakishan K. Meher Gananath N. Dash +1 位作者 Pramod Kumar Meher Mukesh Kumar Raval 《American Journal of Molecular Biology》 2011年第2期79-86,共8页
Development of efficient gene prediction algorithms is one of the fundamental efforts in gene prediction study in the area of genomics. In genomic signal processing the basic step of the identification of protein codi... Development of efficient gene prediction algorithms is one of the fundamental efforts in gene prediction study in the area of genomics. In genomic signal processing the basic step of the identification of protein coding regions in DNA sequences is based on the period-3 property exhibited by nucleotides in exons. Several approaches based on signal processing tools and numerical representations have been applied to solve this problem, trying to achieve more accurate predictions. This paper presents a new indicator sequence based on amino acid sequence, called as aminoacid indicator sequence, derived from DNA string that uses the existing signal processing based time-domain and frequency domain methods to predict these regions within the billions long DNA sequence of eukaryotic cells which reduces the computational load by one-third. It is known that each triplet of bases, called as codon, instructs the cell machinery to synthesize an amino acid. The codon sequence therefore uniquely identifies an amino acid sequence which defines a protein. Thus the protein coding region is attributed by the codons in amino acid sequence. This property is used for detection of period-3 regions using amino acid sequence. Physico-chemical properties of amino acids are used for numerical representation. Various accuracy measures such as exonic peaks, discriminating factor, sensitivity, specificity, miss rate, wrong rate and approximate correlation are used to demonstrate the efficacy of the proposed predictor. The proposed method is validated on various organisms using the standard data-set HMR195, Burset and Guigo and KEGG. The simulation result shows that the proposed method is an effective approach for protein coding prediction. 展开更多
关键词 GENOMICS Bioinformatics CODON Coding region amino acid sequencE Fourier Transform Antinotch Filter Periodicity-3 Indicator sequencE
下载PDF
Pathogenicity and amino acid sequences of hemagglutinin cleavage site and neuraminidase stalk of differently passaged H9N2-avian influenza virus in broilers 被引量:1
2
作者 Houssam A. Shaib Nelly Cochet +4 位作者 Thierry Ribeiro Afif M. Abdel Nour Georges Nemer Maya F. Saade Elie K. Barbour 《Advances in Bioscience and Biotechnology》 2011年第4期198-206,共9页
Low pathogenic Avian Influenza (AI) virus has the ability to evolve to high pathogenic viruses resulting in significant economic losses in the poultry sector. This study aims at assessing the impact of H9N2 viral pass... Low pathogenic Avian Influenza (AI) virus has the ability to evolve to high pathogenic viruses resulting in significant economic losses in the poultry sector. This study aims at assessing the impact of H9N2 viral passaging in broilers and its relatedness to pathogenicity and amino acid (a.a) sequences of the hemagglutinin (HA) cleavage site and neuraminidase (NA) stalk. The original H9N2 AI virus (P0) was used to challenge ten-21 days old broilers. Individual recovery of H9N2 virus from homogenates of trachea, lungs and airsacs was attempted in 9 days old chicken embryos, as a conclusion of the first passage (P1). Tracheal isolates of H9N2 were passaged for a second (P2) and a third (P3) time in broilers, followed by a similar embryonic recovery procedure. The a.a. sequence of a part of HA1 cleavage site and Neuraminidase stalk were compared among the differently passaged viruses;an assessement of the relatedness of the determined a.a. sequences to the pathogenicity in broilers, based on frequency of mortality, morbidity signs, gross and microscopic lesions at 3 days post challenge with the P1, P2, and P3-H9N2, is concluded. An increase in certain morbidity signs and specific lesions was observed in P2- and P3-H9N2 challenged broilers compared to birds challenged with P1-H9N2. A conserved R-S-S-R amino acid sequence at the HA1 cleavage site was observed in the differently passaged H9N2, associated with a variability in the NA stalk-a.a sequences. The passaging of the low pathogenic H9N2 virus in broilers leads to a trend of increase in pathogenicity, manifested in higher frequency of morbidity signs, and of specific gross and microscopic lesions of the examined organs. This passaging was associated with a conserved a.a. sequence of the hemaglutinin cleavage site and a variability in the sequence of the neuraminidase stalk. A detailed study of the potential of the detected variability in the neuraminidase stalk of H9N2 in induction of a higher pathogenicity in broilers will be the subject of future investigations. 展开更多
关键词 H9N2 Avian Influenza PATHOGENICITY Passaging BROILERS amino acid sequences HEMAGGLUTININ (HA) NEURAMINIDASE (NA) STALK
下载PDF
The structural analysis of protein sequences based on the quasi-amino acids code 被引量:2
3
作者 朱平 唐旭清 徐振源 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第1期363-369,共7页
Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper stud... Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper studies protein molecule from the algebraic point of view. The algebraic system (∑, +, *) is introduced, where ∑ is the set of 64 codons. According to the characteristics of (∑, +, *), a novel quasi-amino acids code classification method is introduced and the corresponding algebraic operation table over the set ZU of the 16 kinds of quasi-amino acids is established. The internal relation is revealed about quasi-amino acids. The results show that there exist some very close correlations between the properties of the quasi-amino acids and the codon. All these correlation relationships may play an important part in establishing the logic relationship between codons and the quasi-amino acids during the course of life origination. According to Ma F et al (2003 J. Anhui Agricultural University 30 439), the corresponding relation and the excellent properties about amino acids code are very difficult to observe. The present paper shows that (ZU, +,×) is a field. Furthermore, the operational results display that the eodon tga has different property from other stop codons. In fact, in the mitochondrion from human and ox genomic codon, tga is just tryptophane, is not the stop codon like in other genetic code, it is the case of the Chen W C et al (2002 Acta Biophysiea Siniea 18(1) 87). The present theory avoids some inexplicable events of the 20 kinds of amino acids code, in other words it solves the problem of 'the 64 codon assignments of mRNA to amino acids is probably completely wrong' proposed by Yang (2006 Progress in Modern Biomedicine 6 3). 展开更多
关键词 algebraic operation quasi-amino acids code protein sequences structural analysis
下载PDF
Proteolipid protein 1 gene sequencing of hereditary spastic paraplegia 被引量:1
4
作者 Yu Gao Lumei Chi Yinshi Jin Guangxian Nan 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第2期91-95,共5页
PCR amplification and sequencing of whole blood DNA from an individual with hereditary spastic paraplegia, as well as family members, revealed a fragment of proteolipid protein 1 (PLP1) gene exon 1, which excluded t... PCR amplification and sequencing of whole blood DNA from an individual with hereditary spastic paraplegia, as well as family members, revealed a fragment of proteolipid protein 1 (PLP1) gene exon 1, which excluded the possibility of isomer 1 expression for this family. The fragment sequence of exon 3 and exon 5 was consistent with the proteolipid protein 1 sequence at NCBI. In the proband samples, a PLP1 point mutation in exon 4 was detected at the basic group of position 844, T→C, phenylalanine→leucine. In proband samples from a male cousin, the basic group at position 844 was C, but gene sequencing signals revealed mixed signals of T and C, indicating possible mutation at this locus. Results demonstrated that changes in PLP1 exon 4 amino acids were associated with onset of hereditary spastic paraplegia. 展开更多
关键词 amino acid gene sequencing hereditary spastic paraplegia neural regeneration proteolipid protein 1 sequence analysis
下载PDF
Sequencing of a mutated TNFα by using pinpoint fusion protein expression system
5
作者 缪为民 陈建鹤 +3 位作者 王梁华 周炳荣 娄永华 焦炳华 《Journal of Medical Colleges of PLA(China)》 CAS 1998年第1期19-21,共3页
The amino acid sequencing on mutation region of tumor necmeis factor a derivative 3a(rh-TNFaD3a).Methods: PCR was used to produce the TNF half molecule which contains the mutation "don in itS 5’ end.Then, a fusi... The amino acid sequencing on mutation region of tumor necmeis factor a derivative 3a(rh-TNFaD3a).Methods: PCR was used to produce the TNF half molecule which contains the mutation "don in itS 5’ end.Then, a fusion protein expression system was used to express the TNF half molecule. The fusion protein waspubbed by sanity chromatography and enzymatically cleaved by Xa factor protease to remove fusion vectorpeptide. Finally, the N-terminal amino acid sequencing was performed. Results and Conclusion: The site-specific artificial mutation of TNFαD3a was realized as expected: position 80 Ile→Ser, position 90 Lys→Hisand position 92 Asn→Val. 展开更多
关键词 tumor NECROSIS factor DERIVATIVE mutation amino acid sequence
全文增补中
澳洲坚果抗菌肽分离纯化及其肽段鉴定与分析
6
作者 郭刚军 胡小静 +5 位作者 马尚玄 付镓榕 缪福俊 肖县田 黄克昌 贺熙勇 《食品研究与开发》 CAS 2024年第8期159-166,共8页
以液压压榨澳洲坚果粕为原料,采用碱性蛋白酶水解制备澳洲坚果多肽(macadamia nut peptide⁃0,MNP⁃0),以对金黄色葡萄球菌与白色念珠菌的抑菌活性为跟踪指标,通过超滤、DA201⁃C型大孔吸附树脂、交联葡聚糖凝胶Sephadex G⁃25对其进行逐级... 以液压压榨澳洲坚果粕为原料,采用碱性蛋白酶水解制备澳洲坚果多肽(macadamia nut peptide⁃0,MNP⁃0),以对金黄色葡萄球菌与白色念珠菌的抑菌活性为跟踪指标,通过超滤、DA201⁃C型大孔吸附树脂、交联葡聚糖凝胶Sephadex G⁃25对其进行逐级分离纯化,获得抑菌活性较强的抗菌肽,并运用液相色谱串联质谱(liquid chromatography tandem mass spectrometry,LC⁃MS/MS)技术对其进行肽段组成与氨基酸序列分析。结果表明:超滤分离的不同分子量澳洲坚果多肽在所有多肽中所占质量分数不同,抑菌活性也有所差异。其中,澳洲坚果多肽组分MNP⁃4占比最高,为29.55%;抑菌活性也最强,对金黄色葡萄球菌与白色念珠菌的抑菌圈直径分别为10.01 mm与9.41 mm。大孔吸附树脂纯化多肽组分MNP⁃4的技术条件为75%乙醇溶液为解吸剂,静态吸附3 h,动态洗脱体积60 mL。经大孔吸附树脂与交联葡聚糖凝胶Sephadex G⁃25分离纯化,获得3个澳洲坚果纯化多肽(macadamia nut purified peptide,MPP)组分,其中组分MPP⁃2的抑菌活性最强,对金黄色葡萄球菌与白色念珠菌的抑菌圈直径分别为18.67 mm与16.83 mm,优于多肽MNP⁃0与超滤分离多肽组分。分离纯化的澳洲坚果抗菌活性多肽MPP⁃2含有DDLTDPAPA、VLL、WDY、VPV、WDL、LLW、LWL、FDW 8个肽段,经预测分析,属于抗菌肽的肽段为WDL与FDW,其概率得分a(1.00≥a≥0.50)均为1.00,疏水率均为66.67%,均带有1个负电荷,等电点分别为0.69与0.67,并具有较好的溶解性。研究结果表明澳洲坚果可通过酶法制备具有抗菌活性的肽类成分。 展开更多
关键词 澳洲坚果 抗菌肽 分离纯化 肽段 鉴定 氨基酸序列 分析
下载PDF
氨基酸配方替代喂养对重度牛奶蛋白过敏婴儿肠道菌群特征的影响
7
作者 王永生 于志丹 李小芹 《广西医学》 CAS 2024年第1期39-47,共9页
目的探讨氨基酸配方(AAF)替代喂养对重度牛奶蛋白过敏(CMPA)婴儿肠道菌群特征的影响。方法纳入23例确诊为重度CMPA且人工喂养的≤3月龄婴儿,采用同一品牌AAF进行喂养干预。干预前及干预3个月后,收集所有婴儿的粪便样本,通过16S rRNA高... 目的探讨氨基酸配方(AAF)替代喂养对重度牛奶蛋白过敏(CMPA)婴儿肠道菌群特征的影响。方法纳入23例确诊为重度CMPA且人工喂养的≤3月龄婴儿,采用同一品牌AAF进行喂养干预。干预前及干预3个月后,收集所有婴儿的粪便样本,通过16S rRNA高通量测序及生物信息学分析评估肠道菌群的特征变化。结果干预前后,重度CMPA婴儿肠道菌群Chao1指数、Shannon指数、observed species指数、Simpson指数差异具有统计学意义(P<0.05),Beta多样性具有差异,且组间差异大于组内差异。门水平的相对丰度分析及LEfSe分析结果均显示,AAF干预后重度CMPA婴儿肠道中厚壁菌门、拟杆菌门显著富集。属水平的相对丰度分析结果显示,AAF干预后重度CMPA婴儿肠道中拟杆菌属、粪杆菌属、双歧杆菌属的相对丰度较干预前明显升高,弓形菌属、克雷伯菌属、梭菌属的相对丰度较干预前降低,LEfSe分析结果显示拟杆菌属、粪杆菌属、弓形菌属、克雷伯菌属为在丰度上有显著差异的标志物种。在种水平上相对丰度排名前10的菌群中,产气荚膜梭菌、产酸拟杆菌、丁酸梭菌、格氏乳杆菌、罗伊氏乳杆菌的相对丰度显著升高。结论AAF替代喂养可使得重度CMPA患儿肠道菌群多样性增加,拟杆菌、厚壁菌等的丰度增加。 展开更多
关键词 牛奶蛋白过敏 重度 婴儿 氨基酸配方 肠道菌群 高通量测序技术
下载PDF
三角梅品种‘绿叶樱花’4,5-多巴双加氧酶开放阅读框克隆与分析
8
作者 李建运 姚国琼 +4 位作者 王飞 朱文 李子涵 孙正海 辛培尧 《中南林业科技大学学报》 CAS CSCD 北大核心 2024年第7期153-164,共12页
【目的】多巴双加氧酶(4,5-DOPA dioxygenase extradiol)是甜菜色素生物合成途径的关键酶之一,能催化多巴分解形成甜菜醛氨酸,也是最可能与三角梅最终的花色形成相关的酶蛋白。克隆三角梅多巴双加氧酶基因的开放阅读框(ORF),对其编码的... 【目的】多巴双加氧酶(4,5-DOPA dioxygenase extradiol)是甜菜色素生物合成途径的关键酶之一,能催化多巴分解形成甜菜醛氨酸,也是最可能与三角梅最终的花色形成相关的酶蛋白。克隆三角梅多巴双加氧酶基因的开放阅读框(ORF),对其编码的氨基酸序列进行生物信息学分析,探讨三角梅花色变化机理和甜菜色素代谢途径。【方法】以三角梅品种‘绿叶樱花’的苞片为材料,提取其RNA,并进行逆转录,之后快速转化完成基因的克隆和基因PCR扩增,最后对其编码的氨基酸序列进行保守区预测、信号肽分析、磷酸化位点预测、跨膜信号预测、同源性比对、构建系统进化树以及二、三级结构预测,研究其氨基酸序列的结构和功能。【结果】‘绿叶樱花’的多巴双加氧酶基因ORF序列长801 bp,编码266个氨基酸。ORF序列所编码的氨基酸序列具有cd07363保守结构域,其编码蛋白是一种稳定的酸性亲水蛋白,分子量为29 734.76 kD,等电点为6.26,二级结构包含了11个α螺旋、7个β转角、20个β折叠结构,具有4个磷酸化位点,没有跨膜结构,可能只在细胞质内发挥作用。该序列还与66个序列高度同源,与同科的‘金心双色’、胶果木和梭房叶子花有着相同的进化分支,符合自然进化规律。【结论】‘绿叶樱花’多巴双加氧酶开放阅读框ORF的氨基酸序列属于第三类雌二醇双加氧基因家族,具有该基因家族具有的保守氨基酸序列,表明多巴双加氧酶基因在生成甜菜色素植物中具有独特的保守性,且属于稳定、酸性的亲水蛋白,没有跨膜结构,可能只在细胞质内发挥作用。三角梅中控制花色变化的主要是甜菜色素,研究三角梅甜菜色素合成途径中的关键酶,解析其甜菜色素的合成代谢机制,可为三角梅花色形成机制提供理论参考,有望在今后的工作中,利用转基因手段丰富三角梅花色。 展开更多
关键词 三角梅 多巴双加氧酶 开放阅读框 氨基酸序列 克隆
下载PDF
工业大麻CsIAA1基因克隆及表达分析
9
作者 杨晓娟 阳锡涛 +6 位作者 苏雨娟 黄彤 刘婕 高泽昕 栾明宝 潘根 黄思齐 《中国麻业科学》 2024年第4期213-221,228,共10页
研究以工业大麻云麻7号(Y7)为材料,克隆CsIAA1(Auxin-responsive protein IAA1)基因,通过生物信息学分析CsIAA1序列特征,经RT-qPCR研究CsIAA1组织特异性表达模式;结果表明,CsIAA1基因的CDS全长为621 bp,编码了206个氨基酸,含AUX_IAA保... 研究以工业大麻云麻7号(Y7)为材料,克隆CsIAA1(Auxin-responsive protein IAA1)基因,通过生物信息学分析CsIAA1序列特征,经RT-qPCR研究CsIAA1组织特异性表达模式;结果表明,CsIAA1基因的CDS全长为621 bp,编码了206个氨基酸,含AUX_IAA保守结构域,属于不稳定蛋白;系统进化分析可知,工业大麻CsIAA1与糙叶山黄麻、东山麻等亲缘关系较近;通过烟草叶片瞬时表达和共聚焦试验得知,CsIAA1基因定位在细胞核中;通过RT-qPCR分析发现,在外源IAA处理12 h内,CsIAA1在1 h时快速响应生长素的处理,表达量最高;在工业大麻雄蕊不同发育阶段中,发育初期表达量比发育期和盛花期要高,且随着发育的进行呈逐渐下降趋势,推测CsIAA1参与调控工业大麻雄蕊发育;该研究从工业大麻中克隆出生长素响应基因CsIAA1并对其进行生信和表达分析,为后续探究工业大麻性别发育机制奠定了研究基础. 展开更多
关键词 工业大麻 CsIAA1 氨基酸序列 保守结构域 表达量
下载PDF
Isolation and Characterization of SARS-CoV-2 in Kenya
10
作者 Albina Makio Robinson Mugasiali Irekwa +9 位作者 Matthew Mutinda Munyao Caroline Wangui Njoroge Peter Kipkemboi Rotich Tonny Teya Nyandwaro Joanne Jepkemei Yego Anne Wanjiru Mwangi James Hungo Kimotho Ronald Tanui Vincent Rutto Samson Muuo Nzou 《American Journal of Molecular Biology》 CAS 2024年第2期66-83,共18页
The discovery of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) in Wuhan, Hubei province, China, in December 2019 raised global health warnings. Quickly, in 2020, the virus crossed borders and infected i... The discovery of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) in Wuhan, Hubei province, China, in December 2019 raised global health warnings. Quickly, in 2020, the virus crossed borders and infected individuals across the world, evolving into the COVID-19 pandemic. Notably, early signs of the virus’s existence were observed in various countries before the initial outbreak in Wuhan. As of 12<sup>th</sup> of April, the respiratory disease had infected over 762 million people worldwide, with over 6.8 million deaths recorded. This has led scientists to focus their efforts on understanding the virus to develop effective means to diagnose, treat, prevent, and control this pandemic. One of the areas of focus is the isolation of this virus, which plays a crucial role in understanding the viral dynamics in the laboratory. In this study, we report the isolation and detection of locally circulating SARS-CoV-2 in Kenya. The isolates were cultured on Vero Cercopithecus cell line (CCL-81) cells, RNA extraction was conducted from the supernatants, and reverse transcriptase-polymerase chain reaction (RT-PCR). Genome sequencing was done to profile the strains phylogenetically and identify novel and previously reported mutations. Vero CCL-81 cells were able to support the growth of SARS-CoV-2 in vitro, and mutations were detected from the two isolates sequenced (001 and 002). Genome sequencing revealed the circulation of two isolates that share a close relationship with the Benin isolate with the D614G common mutation identified along the S protein. These virus isolates will be expanded and made available to the Kenya Ministry of Health and other research institutions to advance SARS-CoV-2 research in Kenya and the region. 展开更多
关键词 SARS-CoV-2 COVID-19 Whole Genome sequencing Phylogenetic Analysis Nucleotide Substitutions amino acid Changes
下载PDF
Prediction of the Helix/Sheet Content of Proteins from Their Primary Sequences by Neural Network Method
11
作者 秦红珊 杨新岐 王克起 《Transactions of Tianjin University》 EI CAS 2002年第4期303-307,共4页
The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by u... The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by using the independent non-homologous protein database. It is shown that the average absolute errors for resubstitution test are 0.070 and 0.068 with the standard deviations 0.049 and 0.047 for the prediction of the content of α-helix and β-sheet respectively. For cross-validation test, the average absolute errors are 0.075 and 0.070 with the standard deviations 0.050 and 0.049 for the prediction of the content of α-helix and β-sheet respectively. Compared with the other methods currently available, the BP neural network method combined with the amino acid composition and the biased auto-correlation function features can effectively improve the prediction accuracy. 展开更多
关键词 content prediction of α-helix and β-sheet primary sequence BP neural network amino acid composition biased auto-correlation function
下载PDF
菜籽饼超微粉酶解制备抗氧化活性肽
12
作者 翟晓娜 胡龙彪 +6 位作者 李媛媛 梁亮 胡雪芳 张志民 班世栋 王萍 裴海生 《农业工程学报》 EI CAS CSCD 北大核心 2024年第4期284-291,共8页
为探究菜籽饼超微粉直接酶解制备抗氧化肽技术,该研究以菜籽饼超微粉为原料,利用碱性蛋白酶、风味蛋白酶对其进行酶解,通过测定2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)(ABTS)自由基清除能力、1,1-二苯基-2-苦基肼自由基清除能力和总抗... 为探究菜籽饼超微粉直接酶解制备抗氧化肽技术,该研究以菜籽饼超微粉为原料,利用碱性蛋白酶、风味蛋白酶对其进行酶解,通过测定2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)(ABTS)自由基清除能力、1,1-二苯基-2-苦基肼自由基清除能力和总抗氧化能力表征酶解产物体抗氧化活性,使用膜分离、Sephadex G-15凝胶层析对酶解产物进行分离纯化,利用高效液相色谱-串联质谱联用技术分析鉴定抗氧化活性组分的氨基酸序列。结果表明,风味蛋白酶酶解产物的肽含量较高,并以分子量小于1 kDa肽段为主,碱性蛋白酶解产物以5~10 kDa肽段为主,但同等浓度下(1 mg/mL)的碱性蛋白酶酶解产物抗氧化活性较高;膜分离后,同种酶解产物中低分子量(<1 kDa)组分具有更好的ABTS自由基清除能力和总抗氧化活性;通过凝胶层析分离纯化得到的高抗氧化活性组分J3经氨基酸序列鉴定,结合PeptideRanker生物活性预测筛选得到5个肽段,肽段的N-端均为苯丙氨酸且肽段中疏水性氨基酸的含量占比达50%以上。该结果可为深入开发菜籽饼蛋白资源提供理论参考。 展开更多
关键词 菜籽饼 风味蛋白酶 碱性蛋白酶 膜分离 氨基酸序列 抗氧化活性
下载PDF
涉及序列的发明中的若干问题的研究
13
作者 赵青 《专利代理》 2024年第2期81-86,共6页
通过横向比较专利申请实务中的典型案例并参考《专利审查指南(2023)》相关内容来分析这类案件中的有关单一性和支持的共性和个性问题,讨论在涉及氨基酸序列或DNA序列的发明申请中经常遇到的单一性问题和支持问题及其应对方式,总结出一... 通过横向比较专利申请实务中的典型案例并参考《专利审查指南(2023)》相关内容来分析这类案件中的有关单一性和支持的共性和个性问题,讨论在涉及氨基酸序列或DNA序列的发明申请中经常遇到的单一性问题和支持问题及其应对方式,总结出一些可供参考的应对方式:对于单一性问题,可以先尝试加入功能性/效果性限定并配合“具有总的发明构思”这样的主张,次选是保护主要的一组基础序列及其衍生物;对于支持问题,可以根据发明的具体对象的不同而灵活采用各种间接限定的方式尽量使得保护范围不会过窄。 展开更多
关键词 氨基酸序列 DNA序列 单一性 支持
下载PDF
Phylogenetic Relationships of 11 Bumblebee Species (Hymenoptera:Apidae) Based on Mitochondrial Cytochrome b Gene Sequences 被引量:7
14
作者 邵志勇 茅红新 +1 位作者 符文俊 张亚平 《Zoological Research》 CAS CSCD 北大核心 2002年第5期361-366,共6页
Phylogenetic relationships of 11 bumblebee species,including 5 subgenera:Bombus (5 species),Thoracobombus (3 species),Mendacibombus (1 species),Fervidobombus (1 species) and Pyrobombus (1 species),were analyzed based ... Phylogenetic relationships of 11 bumblebee species,including 5 subgenera:Bombus (5 species),Thoracobombus (3 species),Mendacibombus (1 species),Fervidobombus (1 species) and Pyrobombus (1 species),were analyzed based on the 357?bp mitochondrial cytochrome b gene sequences.There are 65 singleton polymorphic sites and 71 parsimony informative polymorphic sites in this DNA segment,and 45 polymorphic sites within the total 119 translated amino acids segment.Both NJ tree and MP tree show that Mendacibombus (B.avinovielllus) is basal to others,followed by Fervidobombus (B.pensylvanicus);Pyrobombus (B.impatiens) and Bombus are sister subgenera;the subgenus of Bombus is monophyletic,in which B.ignitus diverged first. 展开更多
关键词 BOMBUS Cytochrome b gene DNA sequence amino acid sequence Molecular phylogeny
下载PDF
Protective effects of tilapia(Oreochromis niloticus)skin gelatin hydrolysates on osteoporosis rats induced by retinoic acid
15
作者 Bingtong Liu Liping Sun Yongliang Zhuang 《Food Science and Human Wellness》 SCIE 2022年第6期1500-1507,共8页
Tilapia skin gelatin hydrolysates(TSGH)were obtained by complex protease hydrolysis.The amino acid sequences of 50 peptides in TSGH were identified,and most of these peptides were found to contain the-Gly-Pro-sequence... Tilapia skin gelatin hydrolysates(TSGH)were obtained by complex protease hydrolysis.The amino acid sequences of 50 peptides in TSGH were identified,and most of these peptides were found to contain the-Gly-Pro-sequence.The osteoporosis(OP)rat model induced by retinoic acid was prepared,and the effects of different doses of TSGH on OP in vivo were evaluated.Serum calcium(Ca)and phosphate(P),alkaline phosphatase activity,and osteocalcin levels in OP rats were regulated by TSGH.The bone length,dry weight index,maximum load,and Ca content of OP rats significantly increased by treatment TSGH in a dosedependent manner.Micro-CT images of the femurs and tibias of the rats indicated that the bone mineral density,cortical bone thickness,and cortical/trabecular bone area ratios were recovered and that OP symptoms were improved.Tartrate-resistant acid phosphate and hematoxylin-eosin staining showed that osteoclast numbers and histomorphological changes in the femurs in OP rats could be recovered by TSGH. 展开更多
关键词 amino acid sequence Bone growth MICRO-CT OSTEOPOROSIS Retinoic acid Tilapia skin gelatin hydrolysates
下载PDF
Analysis of the N Protein Sequence Variability in 13 Isolated PRRSV Strains from China
16
作者 Yang Xia Baodan Huang +4 位作者 Bin Wu Yi Zhang Maole Yan Yan Li Jida Li 《Journal of Biosciences and Medicines》 2021年第2期63-75,共13页
<strong>Object</strong>: To analyze porcine reproductive and respiratory syndrome virus (PRRSV) strains from 13 infection cases via the N protein gene and its encoded amino acid sequence and to provide a t... <strong>Object</strong>: To analyze porcine reproductive and respiratory syndrome virus (PRRSV) strains from 13 infection cases via the N protein gene and its encoded amino acid sequence and to provide a theoretical basis for the epidemiological study, prevention and control of porcine reproductive and respiratory syndrome (PRRS). <strong>Methods</strong>: In clinically suspected PRRSV infections, viruses were isolated by extracting viral nucleic acid and amplifying the N protein gene by RT-PCR. Then, the product was purified and sequenced to acquire the whole gene sequence of the N protein and its encoded amino acid sequence. DNASTAR software was used to analyze the homology, the genetic evolution and the derivation of the variability of amino acids of the N protein gene from 13 PRRSV strains and classical domestic and foreign strains. <strong>Results</strong>: Among the thirteen strains of PRRSV isolated from this study, ten strains had the greatest homology with the JXA1 strain (98.9% - 100%), and they belonged to the sublineage 8.7. The remaining three strains had the greatest homology with the NADC30 strain (95.4% - 97.1%), and they belonged to lineage one. The analysis of the variability of N protein amino acids showed that there were high frequency mutations in the five loci of 13 isolated strains of PRRSV as follows: 15th amino acid (10/13), 46<sup>th</sup> amino acid (11/13), 91st amino acid (10/13), 109th amino acid (10/13), and 117th amino acid (10/13). <strong>Conclusion</strong>: In recent years, sublineage 8.7 was the dominant pedigree in field PRRSV epidemic strains in China with lineage one occupying a certain proportion of the field. Four high frequency mutations existed in N protein antigen epitopes of isolated strains from the region. The nuclear localization signal (NLS) structure, specifically the 46<sup>th</sup> amino acid residue of the N protein, was mutated and genetically stable. 展开更多
关键词 PRRSV Nucleocapsid Protein Nuclear Location Signal EPIDEMIOLOGICAL amino acid sequence
下载PDF
紫苏粕蛋白抗氧化活性肽的制备、分离纯化及序列鉴定 被引量:1
17
作者 张恒慧 张志军 +2 位作者 陈士国 叶兴乾 张国华 《中国食品学报》 EI CAS CSCD 北大核心 2023年第9期347-355,共9页
以紫苏粕粉为原料,使用碱性蛋白酶进行水解反应,制备抗氧化活性肽。采用超滤离心、凝胶过滤色谱和反相色谱等分离纯化手段对其富集。结果表明,相较其它3种蛋白酶,碱性蛋白酶Alcalase对紫苏粕蛋白的水解程度最高,约为(25.94±0.21)%... 以紫苏粕粉为原料,使用碱性蛋白酶进行水解反应,制备抗氧化活性肽。采用超滤离心、凝胶过滤色谱和反相色谱等分离纯化手段对其富集。结果表明,相较其它3种蛋白酶,碱性蛋白酶Alcalase对紫苏粕蛋白的水解程度最高,约为(25.94±0.21)%;碱性蛋白酶作用紫苏蛋白后的酶解产物的抗氧化活性最好,对DPPH自由基清除率约为(91.01±0.73)%。酶解上清液经超滤离心分离后最小分子质量组分F1(小于3 ku)抗氧化活性最强,F1组分经Sephadex G-25凝胶过滤色谱分离后按照分子质量大小依次得到P1、P2、P33个组分,其中分子质量最小的P3组分抗氧化活性最高。P3组分经反相色谱分离所得4个组分中,最后被洗脱出来的P3-4组分疏水性最强且DPPH·自由基清除率最高,质量浓度为3μg/mL的P3-4溶液的DPPH·清除率为(58.8±0.78)%。通过LC-MS-MS鉴定,抗氧化活性肽P3-4组分为十二肽,其氨基酸序列为Lys-Leu-Lys-Asp-Ser-Phe-Glu-Arg-Gln-Gly-Met-Val,分子质量为1437.8 u。本研究结果为深入开发紫苏蛋白资源,研发紫苏抗氧化活性肽提供理论参考。 展开更多
关键词 紫苏粕蛋白 抗氧化 分离纯化 生物活性肽 氨基酸序列
下载PDF
蟹肉酶解物的鲜味物质分析及鲜味肽的鉴定 被引量:1
18
作者 温泽华 杨璨 +5 位作者 黄玉荣 于家乐 苏琦 李晓 金艳 张民 《食品研究与开发》 CAS 北大核心 2023年第21期10-17,共8页
以中华绒螯蟹为研究对象,以水解度和感官评价为评价指标,采用木瓜蛋白酶、胰蛋白酶、复合风味酶、中性蛋白酶、碱性蛋白酶、胃蛋白酶对蟹肉进行酶解,利用氨基酸分析仪和高效液相色谱技术对酶解物中呈味物质进行分析,经分离纯化后采用高... 以中华绒螯蟹为研究对象,以水解度和感官评价为评价指标,采用木瓜蛋白酶、胰蛋白酶、复合风味酶、中性蛋白酶、碱性蛋白酶、胃蛋白酶对蟹肉进行酶解,利用氨基酸分析仪和高效液相色谱技术对酶解物中呈味物质进行分析,经分离纯化后采用高效液相色谱串联质谱技术鉴定酶解物中鲜味肽的氨基酸序列。结果表明,中华绒螯蟹蟹肉经胰蛋白酶酶解后,鲜味浓郁、感官评价最佳,其水解度为(51.99±1.85)%,其中鲜味肽、谷氨酸、5’-单磷酸肌苷(5’-inosine monophosphate,5’-IMP)和琥珀酸是主要鲜味物质,经质谱鉴定及鲜味预测筛选,得到14条分子量为795.42~981.55 Da的具有潜在鲜味特性的肽。 展开更多
关键词 中华绒螯蟹 胰蛋白酶 呈味特性 鲜味肽 氨基酸序列
下载PDF
多聚酸性氨基酸对蛋白质性质的影响
19
作者 李亚妃 武沈阳 +3 位作者 褚文丹 周翠燕 施清华 李文奇 《生物学杂志》 CAS CSCD 北大核心 2023年第1期21-26,共6页
选取碳末端富含酸性氨基酸的拟南芥SnRK2.6(sucrose non-fermenting1-related protein kinase 2.6)和人源PDI(protein disulfide isomerase),以及近球形蛋白拟南芥PYL10 (PYR like protein 10),分别将重复酸性氨基酸序列添加到SnRK2.6(1... 选取碳末端富含酸性氨基酸的拟南芥SnRK2.6(sucrose non-fermenting1-related protein kinase 2.6)和人源PDI(protein disulfide isomerase),以及近球形蛋白拟南芥PYL10 (PYR like protein 10),分别将重复酸性氨基酸序列添加到SnRK2.6(1-332)、PDI(1-440)、PYL10碳末端,利用大肠杆菌BL21重组表达,经过亲和层析,离子交换层析和分子排阻层析进行纯化,综合利用分析超速离心技术,分子排阻层析技术以及多角度静态光散射技术,研究人为设计的多聚氨基酸末端对蛋白质分子排阻行为,聚合状态和其他水力学性质的影响。结果发现,多聚酸性氨基酸末端虽不影响蛋白质分子的聚合状态,但会明显减少分子排阻色谱中蛋白质的洗脱体积,影响蛋白质分子的斯托克斯半径和轴长比等水力学性质。 展开更多
关键词 分析超速离心 多角度静态光散射 分子排阻层析 多聚酸性氨基酸 水力学性质
下载PDF
Alterations in gut microbiota are related to metabolite profiles in spinal cord injury 被引量:1
20
作者 Jian-Ning Kang Zheng-Fang Sun +8 位作者 Xin-Yu Li Xiao-Di Zhang Zheng-Xin Jin Ce Zhang Ying Zhang Hui-Yun Wang Na-Na Huang Jian-Hao Jiang Bin Ning 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第5期1076-1083,共8页
Studies have shown that gut microbiota metabolites can enter the central nervous system via the blood-spinal cord barrier and cause neuroinflammation, thus constituting secondary injury after spinal cord injury. To in... Studies have shown that gut microbiota metabolites can enter the central nervous system via the blood-spinal cord barrier and cause neuroinflammation, thus constituting secondary injury after spinal cord injury. To investigate the correlation between gut microbiota and metabolites and the possible mechanism underlying the effects of gut microbiota on secondary injury after spinal cord injury, in this study, we established mouse models of T8–T10 traumatic spinal cord injury. We used 16 S rRNA gene amplicon sequencing and metabolomics to reveal the changes in gut microbiota and metabolites in fecal samples from the mouse model. Results showed a severe gut microbiota disturbance after spinal cord injury, which included marked increases in pro-inflammatory bacteria, such as Shigella, Bacteroides, Rikenella, Staphylococcus, and Mucispirillum and decreases in anti-inflammatory bacteria, such as Lactobacillus, Allobaculum, and Sutterella. Meanwhile, we identified 27 metabolites that decreased and 320 metabolites that increased in the injured spinal cord. Combined with pathway enrichment analysis, five markedly differential amino acids(L-leucine, L-methionine, L-phenylalanine, L-isoleucine and L-valine) were screened out, which play a pivotal role in activating oxidative stress and inflammatory responses following spinal cord injury. Integrated correlation analysis indicated that the alteration of gut microbiota was related to the differences in amino acids, which suggests that disturbances in gut microbiota might participate in the secondary injury through the accumulation of partial metabolites that activate oxidative stress and inflammatory responses. Findings from this study provide a new theoretical basis for improving the secondary injury after spinal cord injury through fecal microbial transplantation. 展开更多
关键词 16S rRNA gene amplicon sequencing amino acid metabolism DYSBACTERIOSIS gut microbiota inflammation metabolic disturbance METABOLITES metabolomics secondary injury spinal cord injury
下载PDF
上一页 1 2 28 下一页 到第
使用帮助 返回顶部