A reduced computational load protein coding predictor using equivalent amino acid sequence of DNA string with period-3 based time and frequency domain analysis

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.

Pathogenicity and amino acid sequences of hemagglutinin cleavage site and neuraminidase stalk of differently passaged H9N2-avian influenza virus in broilers

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.

The structural analysis of protein sequences based on the quasi-amino acids code

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）.

Prediction of the Helix/Sheet Content of Proteins from Their Primary Sequences by Neural Network Method

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.

Phylogenetic Relationships of 11 Bumblebee Species (Hymenoptera:Apidae) Based on Mitochondrial Cytochrome b Gene Sequences

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.

Analysis of the N Protein Sequence Variability in 13 Isolated PRRSV Strains from China

Object: 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). Methods: 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. Results: 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), 46th amino acid (11/13), 91st amino acid (10/13), 109th amino acid (10/13), and 117th amino acid (10/13). Conclusion: 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 46th amino acid residue of the N protein, was mutated and genetically stable.

澳洲坚果抗菌肽分离纯化及其肽段鉴定与分析

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。

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

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。

史氏鲟鱼精肽的制备、体外抗炎活性评价和结构表征

旨在研究史氏鲟(Acipenser schrenckii)鱼精肽(sturgeon milt peptide,SMP)的抗炎潜力及其分子特性。首先对鲟鱼精蛋白进行提取、酶解、纯化得到SMP,评估了其对一氧化氮(NO)和牛血清白蛋白变性的抑制效果。然后利用现代波谱技术测定其分子质量、二级结构、晶体结构、质子峰分布和氨基酸序列等,并基于此预测氨基酸序列的抗炎活性。结果显示,在10 mg/mL质量浓度下,SMP对NO和牛血清蛋白变性的抑制率分别为45.33%和60.34%,显著高于鲟鱼精蛋白(P<0.05)。SMP中碱性和疏水性氨基酸含量分别占37.45%和36.77%,其中精氨酸占比最高(16.28%)。SMP分子质量集中于206~1040 Da之间,主要呈现不规则的无定形结构,水溶液状态下暴露更多的疏水性基团。SMP中含有较多的短肽,包括MPY、YWH、YPY和VPPL等,这些肽序列具有抗炎特性。综上,SMP具有潜在的抗炎活性,是一种有前途的天然抗炎肽来源,具有进一步开发和应用的潜力。

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

【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。

低氮处理对玉米早期发育胚乳中氨基酸水平和转录组的影响

氮素是影响玉米生长发育、产量和籽粒品质形成所必需的营养元素。为挖掘早期发育的玉米胚乳响应低氮胁迫的关键基因,揭示玉米胚乳抵御低氮胁迫的生理响应及分子机制,本研究在低氮和足氮处理下,对授粉后第6天的自交系B73玉米胚乳进行氨基酸含量、氨基酸衍生物含量分析和转录组测序。生理测定表明,低氮胁迫下,玉米胚乳中10种氨基酸或氨基酸衍生物含量升高,其中苏氨酸、β-氨基异丁酸、组氨酸、β-丙氨酸、赖氨酸含量升高程度最大,其升高范围介于71.1%~153.1%;而其余21种氨基酸或氨基酸衍生物含量降低,其中鸟氨酸、胱氨酸、天冬酰胺、苯丙氨酸、α-氨基丁酸含量下降程度最大,其下降程度范围介于51.6%~65.8%。转录组测序结果表明,与足氮处理相比,低氮胁迫下玉米胚乳中鉴定到3185个显著上调和2612个显著下调的差异表达基因。进一步检测到参与氮代谢途径和氰基氨基酸代谢途径的差异表达基因分别为12和9个,AP2/ERF-ERF、b ZIP、WRKY差异表达转录因子家族成员分别为20、10和21个。这些候选基因可能是玉米胚乳抵御低氮胁迫响应的重要基因资源,其为玉米胚乳应答低氮胁迫的分子机制及耐低氮玉米新品种培育奠定基础。

工业大麻CsIAA1基因克隆及表达分析

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.

Isolation and Characterization of SARS-CoV-2 in Kenya

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 12th 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.

菜籽饼超微粉酶解制备抗氧化活性肽

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。

涉及序列的发明中的若干问题的研究

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。

2001—2022年鸽圆环病毒的遗传变异分析

鸽圆环病毒(Pigeon circovirus,PiCV)是近几年发现的一种能引起感染鸽免疫抑制的病毒,属于圆环病毒科圆环病毒属。为研究PiCV的流行特征和遗传进化规律,试验从GenBank中选取208株PiCV全基因组序列,利用生物信息学软件,通过构建PiCV全基因组系统发育树,进行核苷酸同源性比较、氨基酸序列比对分析、抗原表位分析和基因重组等方式对其进行遗传变异分析。结果表明:基于构建的系统发育树可将208株PiCV毒株分为A(54.81%,114/208)和B(45.19%,94/208)两个基因型,其中A基因型可进一步分为A-1、A-2、A-3、A-4、A-55个不同的亚群,B基因型可进一步分为B-1、B-2、B-3、B-44个不同的亚群。208株PiCV全基因组序列的相似性为83.8%~100%。PiCV Cap蛋白氨基酸序列上存在氨基酸的点突变、缺失和插入等情况。208株PiCV全基因组序列中存在大量重组事件(44个),涉及A基因型序列中所包含的遗传物质的直接交换及ORF C1基因小片段的转移。说明PiCV的变异具有多样性。

Amino Acid Sequence of an Excitatory Insect-selective Toxin (BmK IT) From Venom of the Scorpion Buthus martensi Karsch

The insect-selective neurotoxin(BmK IT) of scorpion Buthus martensi Karsch was first reduced and S-alkylated, and then digested by TPCK-trypsin and Staphylococcus aureus V-8 Protease. The enzymatic peptides were purified on TLC-plastic sheet and submitted to determine their amino acid compositions and sequences. The sequence of the 70 amino acid residues of BmK IT was established with reference to the primary structure of AaH IT, another excitatory insect-selective toxin from the venom of North African scorpion Androctonus australis Hector. About 75% of the homologous sequence was found in the molecules of BmK IT and AaH IT. It is obvious that the results contribute toward better understanding of the molecular structure characteristics, structure/activity relationship of scorpion insect-selective toxins, and they can serve as the molecular basis for utilizing the toxins as a tool to clarify molecular mechanism involved in channel gating, and to infer the possibility of developing them as new selective bioinsecticides.

The Variability of Amino Acid Sequences in Hepatitis B Virus

Hepatitis B virus(HBV) is an important human pathogen belonging to the Hepadnaviridae family, Orthohepadnavirus genus. Over 240 million people are infected with HBV worldwide. The reverse transcription during its genome replication leads to low fidelity DNA synthesis, which is the source of variability in the viral proteins. To investigate the variability quantitatively, we retrieved amino acid sequences of 5,167 records of all available HBV genotypes(A–J) from the Genbank database. The amino acid sequences encoded by the open reading frames(ORF) S/C/P/X in the HBV genome were extracted and subjected to alignment. We analyzed the variability of the lengths and the sequences of proteins as well as the frequencies of amino acids. It comprehensively characterized the variability and conservation of HBV proteins at the level of amino acids. Especially for the structural proteins, hepatitis B surface antigens(HBsAg), there are potential sites critical for virus assembly and immune recognition. Interestingly, the preS1 domains in HBsAg were variable at some positions of amino acid residues, which provides a potential mechanism of immune-escape for HBV, while the preS2 and S domains were conserved in the lengths of protein sequences. In the S domain, the cysteine residues and the secondary structures of the alpha-helix and beta-sheet were likely critical for the stable folding of all HBsAg components. Also, the preC domain and C-terminal domain of the core protein are highly conserved. However, the polymerases(HBpol) and the HBx were highly variable at the amino acid level. Our research provides a basis for understanding the conserved and important domains of HBV viral proteins, which could be potential targets for anti-virus therapy.

Proteolipid protein 1 gene sequencing of hereditary spastic paraplegia

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.

Amino acid sequence of BmK AS, a novel polypeptide activator of ryanodine receptor on skeletal muscle

IN ref.[1],we have described a novel activator(BmK AS)of ryanodine receptor on skeletal muscle,which was obtained from the venom of scorpion Buthus martensi Karsch.This noteprovides the complete amino acid sequence of the active polypeptide,BmK AS.The molecularweight ot the polypeptide thus determined was 7 698 u,calculated based on its sequence(to-tally 66 residues),which was coincident with the value of 7 696.26 u determined by electro-