馬海梅+吾拉木·馬木提+張峰波+龐盼+趙慧+丁劍冰

[摘要] 目的 分析新疆細(xì)粒棘球蚴EgAgB8/3蛋白氨基酸序列，了解該蛋白特性，預(yù)測(cè)其抗原表位，為進(jìn)一步研究和選擇包蟲病免疫學(xué)診斷與防治的最佳候選抗原提供理論依據(jù)。 方法 利用生物信息學(xué)方法推測(cè)EgAgB8/3蛋白氨基酸序列及理化性質(zhì)，用不同的生物信息學(xué)軟件分析EgAgB8/3蛋白的特性及二級(jí)結(jié)構(gòu)，并結(jié)合多參數(shù)預(yù)測(cè)其抗原表位。 結(jié)果 EgAgB8/3抗原是由75個(gè)氨基酸殘基組成的多肽，相對(duì)分子質(zhì)量為8.58×103，等電點(diǎn)為8.5；蛋白特性分析顯示EgAgB8/3蛋白α螺旋、β折疊、β轉(zhuǎn)角和無規(guī)卷曲等二級(jí)結(jié)構(gòu)特點(diǎn)，有3個(gè)β轉(zhuǎn)角較好區(qū)域可作為表位所在參考區(qū)段；3種軟件多參數(shù)綜合分析預(yù)測(cè)，EgAgB8/3蛋白抗原表位集中在1～7（FVVVAHA）、6～19（HADDDDDEVTKTKK）、32～38（FQSDPLG）區(qū)段。 結(jié)論 運(yùn)用生物信息學(xué)分析方法預(yù)測(cè)到EgAgB8/3抗原3個(gè)B細(xì)胞的優(yōu)勢(shì)表位，對(duì)進(jìn)一步研究EgAgB8/3抗原性和研發(fā)更有價(jià)值的包蟲病免疫診斷與防治靶標(biāo)具有重要意義。

[關(guān)鍵詞] 細(xì)粒棘球絳蟲；EgAgB8/3；生物信息學(xué)；表位

[中圖分類號(hào)] R383.3 [文獻(xiàn)標(biāo)識(shí)碼] A [文章編號(hào)] 1673-7210（2017）05（b）-0008-04

[Abstract] Objective To analyze the amino acid sequencing of EgAgB8/3 protein from Echinococcus granulosus in Xinjiang Uygur Autonomous Region， understand the characteristics of this protein， predict the epitope of its antigen， so as to provide theoretical foundation for further studying and selecting the best alternative antigen of immunological diagnosis and prevention of echinococcosis. Methods The amino acid sequencing and physicochemical property of EgAgB8/3 proteins were predicted by bioinformatics method， the characteristics and secondary structure of EgAgB8/3 proteins were analyzed by different bioinformatics software， and its antigenic epitope was predicted combined with multiple parameters. Results EgAgB8/3 antigen was polypeptide composed of 75 amino acid residues， the relative molecular mass was 8.58×103， isoelectric point was 8.5； the analysis of protein characteristics showed the secondary structure characteristics of α-helix， β-sheet， β-turn and random coil of EgAgB8/3 proteins， among which， there were 3 better areas of β-turn that could be as reference segment of epitope； comprehensive analysis of three software and multiple parameters predicted that， the epitope of EgAgB8/3 protein antigen was mainly located in 1-7 （FVVVAHA）， 6-19 （HADDDDDEVTKTKK） and 32-38 （FQSDPLG）. Conclusion The prediction for dominant epitope of three B cell epitopes of EgAgB8/3 protein by bioinformatics method has important significance for further studying the antigenicity of EgAgB8/3 and developing more valuable target for immunological diagnosis and prevention of echinococcosis.

[Key words] Echinococcus granulosus； EgAgB8/3； Bioinformatics； Epitope

細(xì)粒棘球蚴所致囊型包蟲?。╟ystic echinococcosis，CE）是一種嚴(yán)重人畜共患寄生蟲病[1]。我國(guó)CE流行區(qū)主要集中在內(nèi)蒙古、新疆、青海、西藏、寧夏、四川、甘肅7個(gè)省份的牧區(qū)，給當(dāng)?shù)厝松】?、?jīng)濟(jì)發(fā)展和社會(huì)和諧穩(wěn)定帶來嚴(yán)重影響。尋找特異性強(qiáng)、敏感性高的候選抗原靶標(biāo)分子是CE診斷和防治的當(dāng)務(wù)之急。細(xì)粒棘球蚴抗原B（Echinococcus granulosus antigen B，EgAgB）是包囊囊液中含量多、免疫原性強(qiáng)、敏感性和特異性高的脂蛋白，為國(guó)內(nèi)外研究熱點(diǎn)[2-5]。EgAgB包括EgAgB8/1、EgAgB8/2、EgAgB8/3、EgAgB8/4、EgAgB8/5等5個(gè)約為8 kD的亞單位，各亞單位對(duì)不同類型包蟲病診斷的敏感性和特異性效能有明顯差異[6-7]。本課題組前期研究發(fā)現(xiàn)，5個(gè)亞單位中以EgAgB8/3在細(xì)粒棘球絳蟲成蟲階段的表達(dá)最為顯著[8-9]，提示其有望成為開發(fā)研制包蟲病防治疫苗和診斷試劑最有潛力的后備靶抗原。為進(jìn)一步探討EgAgB8/3抗原結(jié)構(gòu)特點(diǎn)，本研究用生物信息學(xué)方法預(yù)測(cè)分析其抗原表位，以期為包蟲病診斷防治最佳候選抗原的選擇提供一些理論支撐。

[摘要] 目的 分析新疆細(xì)粒棘球蚴EgAgB8/3蛋白氨基酸序列，了解該蛋白特性，預(yù)測(cè)其抗原表位，為進(jìn)一步研究和選擇包蟲病免疫學(xué)診斷與防治的最佳候選抗原提供理論依據(jù)。 方法 利用生物信息學(xué)方法推測(cè)EgAgB8/3蛋白氨基酸序列及理化性質(zhì)，用不同的生物信息學(xué)軟件分析EgAgB8/3蛋白的特性及二級(jí)結(jié)構(gòu)，并結(jié)合多參數(shù)預(yù)測(cè)其抗原表位。 結(jié)果 EgAgB8/3抗原是由75個(gè)氨基酸殘基組成的多肽，相對(duì)分子質(zhì)量為8.58×103，等電點(diǎn)為8.5；蛋白特性分析顯示EgAgB8/3蛋白α螺旋、β折疊、β轉(zhuǎn)角和無規(guī)卷曲等二級(jí)結(jié)構(gòu)特點(diǎn)，有3個(gè)β轉(zhuǎn)角較好區(qū)域可作為表位所在參考區(qū)段；3種軟件多參數(shù)綜合分析預(yù)測(cè)，EgAgB8/3蛋白抗原表位集中在1～7（FVVVAHA）、6～19（HADDDDDEVTKTKK）、32～38（FQSDPLG）區(qū)段。 結(jié)論 運(yùn)用生物信息學(xué)分析方法預(yù)測(cè)到EgAgB8/3抗原3個(gè)B細(xì)胞的優(yōu)勢(shì)表位，對(duì)進(jìn)一步研究EgAgB8/3抗原性和研發(fā)更有價(jià)值的包蟲病免疫診斷與防治靶標(biāo)具有重要意義。

[關(guān)鍵詞] 細(xì)粒棘球絳蟲；EgAgB8/3；生物信息學(xué)；表位

[中圖分類號(hào)] R383.3 [文獻(xiàn)標(biāo)識(shí)碼] A [文章編號(hào)] 1673-7210（2017）05（b）-0008-04

[Abstract] Objective To analyze the amino acid sequencing of EgAgB8/3 protein from Echinococcus granulosus in Xinjiang Uygur Autonomous Region， understand the characteristics of this protein， predict the epitope of its antigen， so as to provide theoretical foundation for further studying and selecting the best alternative antigen of immunological diagnosis and prevention of echinococcosis. Methods The amino acid sequencing and physicochemical property of EgAgB8/3 proteins were predicted by bioinformatics method， the characteristics and secondary structure of EgAgB8/3 proteins were analyzed by different bioinformatics software， and its antigenic epitope was predicted combined with multiple parameters. Results EgAgB8/3 antigen was polypeptide composed of 75 amino acid residues， the relative molecular mass was 8.58×103， isoelectric point was 8.5； the analysis of protein characteristics showed the secondary structure characteristics of α-helix， β-sheet， β-turn and random coil of EgAgB8/3 proteins， among which， there were 3 better areas of β-turn that could be as reference segment of epitope； comprehensive analysis of three software and multiple parameters predicted that， the epitope of EgAgB8/3 protein antigen was mainly located in 1-7 （FVVVAHA）， 6-19 （HADDDDDEVTKTKK） and 32-38 （FQSDPLG）. Conclusion The prediction for dominant epitope of three B cell epitopes of EgAgB8/3 protein by bioinformatics method has important significance for further studying the antigenicity of EgAgB8/3 and developing more valuable target for immunological diagnosis and prevention of echinococcosis.

[Key words] Echinococcus granulosus； EgAgB8/3； Bioinformatics； Epitope

細(xì)粒棘球蚴所致囊型包蟲?。╟ystic echinococcosis，CE）是一種嚴(yán)重人畜共患寄生蟲病[1]。我國(guó)CE流行區(qū)主要集中在內(nèi)蒙古、新疆、青海、西藏、寧夏、四川、甘肅7個(gè)省份的牧區(qū)，給當(dāng)?shù)厝松】?、?jīng)濟(jì)發(fā)展和社會(huì)和諧穩(wěn)定帶來嚴(yán)重影響。尋找特異性強(qiáng)、敏感性高的候選抗原靶標(biāo)分子是CE診斷和防治的當(dāng)務(wù)之急。細(xì)粒棘球蚴抗原B（Echinococcus granulosus antigen B，EgAgB）是包囊囊液中含量多、免疫原性強(qiáng)、敏感性和特異性高的脂蛋白，為國(guó)內(nèi)外研究熱點(diǎn)[2-5]。EgAgB包括EgAgB8/1、EgAgB8/2、EgAgB8/3、EgAgB8/4、EgAgB8/5等5個(gè)約為8 kD的亞單位，各亞單位對(duì)不同類型包蟲病診斷的敏感性和特異性效能有明顯差異[6-7]。本課題組前期研究發(fā)現(xiàn)，5個(gè)亞單位中以EgAgB8/3在細(xì)粒棘球絳蟲成蟲階段的表達(dá)最為顯著[8-9]，提示其有望成為開發(fā)研制包蟲病防治疫苗和診斷試劑最有潛力的后備靶抗原。為進(jìn)一步探討EgAgB8/3抗原結(jié)構(gòu)特點(diǎn)，本研究用生物信息學(xué)方法預(yù)測(cè)分析其抗原表位，以期為包蟲病診斷防治最佳候選抗原的選擇提供一些理論支撐。

[摘要] 目的 分析新疆細(xì)粒棘球蚴EgAgB8/3蛋白氨基酸序列，了解該蛋白特性，預(yù)測(cè)其抗原表位，為進(jìn)一步研究和選擇包蟲病免疫學(xué)診斷與防治的最佳候選抗原提供理論依據(jù)。 方法 利用生物信息學(xué)方法推測(cè)EgAgB8/3蛋白氨基酸序列及理化性質(zhì)，用不同的生物信息學(xué)軟件分析EgAgB8/3蛋白的特性及二級(jí)結(jié)構(gòu)，并結(jié)合多參數(shù)預(yù)測(cè)其抗原表位。 結(jié)果 EgAgB8/3抗原是由75個(gè)氨基酸殘基組成的多肽，相對(duì)分子質(zhì)量為8.58×103，等電點(diǎn)為8.5；蛋白特性分析顯示EgAgB8/3蛋白α螺旋、β折疊、β轉(zhuǎn)角和無規(guī)卷曲等二級(jí)結(jié)構(gòu)特點(diǎn)，有3個(gè)β轉(zhuǎn)角較好區(qū)域可作為表位所在參考區(qū)段；3種軟件多參數(shù)綜合分析預(yù)測(cè)，EgAgB8/3蛋白抗原表位集中在1～7（FVVVAHA）、6～19（HADDDDDEVTKTKK）、32～38（FQSDPLG）區(qū)段。 結(jié)論 運(yùn)用生物信息學(xué)分析方法預(yù)測(cè)到EgAgB8/3抗原3個(gè)B細(xì)胞的優(yōu)勢(shì)表位，對(duì)進(jìn)一步研究EgAgB8/3抗原性和研發(fā)更有價(jià)值的包蟲病免疫診斷與防治靶標(biāo)具有重要意義。

[關(guān)鍵詞] 細(xì)粒棘球絳蟲；EgAgB8/3；生物信息學(xué)；表位

[中圖分類號(hào)] R383.3 [文獻(xiàn)標(biāo)識(shí)碼] A [文章編號(hào)] 1673-7210（2017）05（b）-0008-04

[Abstract] Objective To analyze the amino acid sequencing of EgAgB8/3 protein from Echinococcus granulosus in Xinjiang Uygur Autonomous Region， understand the characteristics of this protein， predict the epitope of its antigen， so as to provide theoretical foundation for further studying and selecting the best alternative antigen of immunological diagnosis and prevention of echinococcosis. Methods The amino acid sequencing and physicochemical property of EgAgB8/3 proteins were predicted by bioinformatics method， the characteristics and secondary structure of EgAgB8/3 proteins were analyzed by different bioinformatics software， and its antigenic epitope was predicted combined with multiple parameters. Results EgAgB8/3 antigen was polypeptide composed of 75 amino acid residues， the relative molecular mass was 8.58×103， isoelectric point was 8.5； the analysis of protein characteristics showed the secondary structure characteristics of α-helix， β-sheet， β-turn and random coil of EgAgB8/3 proteins， among which， there were 3 better areas of β-turn that could be as reference segment of epitope； comprehensive analysis of three software and multiple parameters predicted that， the epitope of EgAgB8/3 protein antigen was mainly located in 1-7 （FVVVAHA）， 6-19 （HADDDDDEVTKTKK） and 32-38 （FQSDPLG）. Conclusion The prediction for dominant epitope of three B cell epitopes of EgAgB8/3 protein by bioinformatics method has important significance for further studying the antigenicity of EgAgB8/3 and developing more valuable target for immunological diagnosis and prevention of echinococcosis.

[Key words] Echinococcus granulosus； EgAgB8/3； Bioinformatics； Epitope

細(xì)粒棘球蚴所致囊型包蟲病（cystic echinococcosis，CE）是一種嚴(yán)重人畜共患寄生蟲病[1]。我國(guó)CE流行區(qū)主要集中在內(nèi)蒙古、新疆、青海、西藏、寧夏、四川、甘肅7個(gè)省份的牧區(qū)，給當(dāng)?shù)厝松】?、?jīng)濟(jì)發(fā)展和社會(huì)和諧穩(wěn)定帶來嚴(yán)重影響。尋找特異性強(qiáng)、敏感性高的候選抗原靶標(biāo)分子是CE診斷和防治的當(dāng)務(wù)之急。細(xì)粒棘球蚴抗原B（Echinococcus granulosus antigen B，EgAgB）是包囊囊液中含量多、免疫原性強(qiáng)、敏感性和特異性高的脂蛋白，為國(guó)內(nèi)外研究熱點(diǎn)[2-5]。EgAgB包括EgAgB8/1、EgAgB8/2、EgAgB8/3、EgAgB8/4、EgAgB8/5等5個(gè)約為8 kD的亞單位，各亞單位對(duì)不同類型包蟲病診斷的敏感性和特異性效能有明顯差異[6-7]。本課題組前期研究發(fā)現(xiàn)，5個(gè)亞單位中以EgAgB8/3在細(xì)粒棘球絳蟲成蟲階段的表達(dá)最為顯著[8-9]，提示其有望成為開發(fā)研制包蟲病防治疫苗和診斷試劑最有潛力的后備靶抗原。為進(jìn)一步探討EgAgB8/3抗原結(jié)構(gòu)特點(diǎn)，本研究用生物信息學(xué)方法預(yù)測(cè)分析其抗原表位，以期為包蟲病診斷防治最佳候選抗原的選擇提供一些理論支撐。

[16] Ahn CS，Han X，Bae YA，et al. Alteration of immunoproteome profile of Echinococcus granulosus hydatid fluid with progression of cystic echinococcosis [J]. Parasit Vectors，2015，8：1-10.

[17] 黃艷新，鮑永利，李玉新，等.抗原表位預(yù)測(cè)的免疫信息學(xué)方法研究進(jìn)展[J].中國(guó)免疫學(xué)雜志，2008，24（9）：857-861.

[18] Almeida RA，Luther DA，Patel D，et al. Predicted antigenic regions of Streptococcus uberis adhesion molecule（SUAM）are involved in adherence to and internalization into mammary epithelial cells [J]. Vet Microbiol，2011，148（2-4）：323-328.

[19] Saha S，Raghava GP. Prediction of continuous B-cell epitopes in an antigen using recurrent neural network [J]. Proteins，2006，65（1）：40-48.

[20] EL-Manzalawy Y，Honanvar V. Recent advances in B-cell epitope prediction methods [J]. Immunome Res，2010，6（2）：52-60.

[21] Ruth ES，Ricardo NG，Dania OGA，et al. An overview of bioinformatics tools for epitope prediction：Implications on vaccine development [J]. J Biomed Inform，2015，53：405-414.

（收稿日期：2017-01-05 本文編輯：張瑜杰）