牛乳腺炎粪肠球菌溶血素CylA基因编码多肽的理化特性及抗原性分析  

Physicochemical properties and antigenicity of the peptide encoded by the hemolysin CylA gene of Enterococcus faecalis from bovine mastitis

作　　者：布日额[1,2,3] 吴金花 锡林高娃[1,2,3] 邢家辉 丹妮[1,2,3] 刘凯 BU Ri-e;WU Jin-hua;XI Lingao-wa;XING Jiahui;DAN Ni;LIU Kai(College of Life Science and Food Engineering,Inner Mongolia University for Nationalities,Tongliao 028043,Inner Mongolia,China;Inner Mongolia Autonomous Region Engineering Technology Research Center of Prevention and Control the Pathogenic Bacteriain Milk;Research Institute for Pathogenic in Milk of Inner Mongolia University for Nationalities)

机构地区：[1]内蒙古民族大学生命科学与食品学院,内蒙古通辽028042 [2]内蒙古自治区乳源性致病菌防控工程技术研究中心 [3]内蒙古民族大学乳源性致病菌研究所

出　　处：《中国病原生物学杂志》2021年第9期1020-1024,共5页Journal of Pathogen Biology

基　　金：国家自然科学基金项目(No.32060798);内蒙古自然科学基金项目(No.2019LH03015;2021MS03084);内蒙古民族大学生命科学与食品学院资源生物与生态研究所2020年资助项目。

摘　　要：目的预测和分析牛乳腺炎粪肠球菌溶血素CylA基因的抗原性和相关的理化性质。方法克隆牛乳腺炎粪肠球菌溶血素CylA基因,并在测序基础上利用生物信息软件分析CylA基因编码的多肽抗原可及性及其理化特性。结果成功克隆CylA基因,经测序CylA基因序列序长度为978 bp,与NCBI上公布的CylA序列(JQ794947.1)相似度为99.0%,核苷酸序列有5处出现变异,分别是168位的碱基由T→G,587位碱基由C→T,735位插入碱基C,781位插入碱基G,826位碱基由T→A。利用生物信息学软件分析其理化性质结果显示,该片段多肽相对分子质量为27.5 ku,等电点为4.69,带负电荷残基39个,带正电荷残基26个,分子式为C1213H1920N326O393S3,α螺旋占29.69%,β折叠占9.77%,无规则折叠占37.87%,2~25位氨基酸为跨膜区;具有良好的抗原可及性,从2~8位氨基酸,从92~160位氨基酸区间均匀分布抗原可及性。结论溶血素CylA基因编码多肽具有明显的跨膜分泌特性,丰富的折叠结构和广泛区域的抗原可及性,对相应基因工程疫苗的研制及检测抗原开发具有重要意义。Objective To predict and determine the antigenicity and related physicochemical properties of the hemolysin CylA gene of Enterococcus faecalis from bovine mastitis. Methods The hemolysin CylA gene of E. faecalis from bovine mastitis was cloned, and the accessibility and physicochemical properties of the peptide antigen encoded by the gene were analyzed using bioinformatic software based on sequencing. Results Results indicated that the CylA gene was successfully cloned. The CylA gene sequence was 978 bp in length, and the sequence was 99.0% similar to the CylA sequence published in NCBI(JQ794947.1). There were five variations in the nucleotide sequence, namely, T to G at position 168, C to T at position 587, insertion of C at position 735, insertion of G at position 781, and T to A at position 826. Results indicated that the molecular weight of the peptide was 27.5 ku, its isoelectric point was 4.69, it had 39 negatively charged residues, 26 positively charged residues, and its molecular formula was C1213H1920N326O393S3. α-helices accounted for 29.69% of its secondary structure, β-sheets accounted for 77%, and random coils accounted for 37. Amino acids 2-25 were a trans-membrane region. The peptide has good antigen accessibility, which was evenly distributed from amino acids 2 to 8 and from amino acids 92 to 160. Conclusion The polypeptide encoded by the hemolysin CylA gene had obvious transmembrane and secretory characteristics, a structure with abundant folds, and extensive antigen accessibility. This polypeptide will be crucial to the corresponding development of genetically engineered vaccines and antigen detection.

关 键 词：粪肠球菌 CylA基因 生物信息学分析 

分 类 号：R378.1[医药卫生—病原生物学]