摘要
目的肺表面活性蛋白B(pulmonary surfactant-associated protein B,SFTPB)作为一种重要的特异性蛋白,其有关肺癌预后的研究正逐渐受到关注。本研究拟采用生物信息学方法分析SFTPB结构并预测其功能,以期为肺癌诊疗提供思路。方法采用Expasy服务器工具分析SFTPB蛋白理化性质;采用ScanProsite分析SFTPB功能结构域;NCBI分析SFTPB保守结构域;STRING预测SFTPB与其他蛋白质交互作用;Jpred 4预测其二级结构;Swiss-Mode预测其三级结构,并用PDBsum中拉氏图进行结构模型评价。结果 SFTPB蛋白由381个氨基酸组成,等电点为5.27,不稳定指数为58.32,脂肪系数为96.51。二级结构预测发现14个α-螺旋(占51.7%),1个β-折叠。三级结构预测拉氏图分析落在最大允许区域内的氨基酸残基占95.6%,相似波形图得分均值>0.6,表明预测模型B结构较稳定。SFTPB亚细胞定位主要位于细胞外、细胞核和内质网,主要有两类功能结构域(共8个),为鞘脂激活蛋白A(sphingolipid activator protein A,SAP-A)和SAP-B。蛋白质互作发现其可能与CTSH、CSF2RA和NAPSA等蛋白存在交互关系。结论 SFTPB蛋白是一种以α-螺旋为主的不稳定亲脂性蛋白,由肺泡细胞分泌,主要作用于细胞外,可稳定肺泡表面张力,对防止肺损伤有重要作用,可能有助于肺癌诊疗。
OBJECTIVE Pulmonary surfactant-associated protein B(SFTPB)is an important specific protein in lung surfactant proteins,which is reported widely on the studies of prognosis of lung cancer.Bioinformatics methods are comprehensivcly used in this study to analyze the structure of SFTPB and promote function predictions,aiming at providing ideas for the diagnosis and treatment of lung cancer.METHODS Tools of ExPASy Server were employed to analyze the physicochemical properties of SFTPB protein.The functional domain of SFTPB was analyzed by SeanProsite,while NCBI was used to analyze the conserved domain of SFTPB.The interaction of SFTPB with other proteins was predicted by STRING.The secondary structure was predicted by Jpred 4.Swiss-Mode predicted its three-level structure.Additionally,Ramachandran plot in PDBsum was used to evaluate the structural model.RESULTS The SFTPB protein was consisted of 381 amino acids with an isoelectric point of 5.27,an instability index of 58.32,and a fat coefficient of 96.51.There were 14 a helices(accounting for 51.7%)and 1β-sheet in the secondary structure prediction.The Ramachandran plot analyzed 95.6%of the amino acid residues in the maximum allowable region,and the average value of the similar waveforms was greater than 0.6,indicating that the prediction model B was relatively stable.Its subcellular localization was mainly located outside the cell,the nucleus and the endoplasmic reticulum.There were two main functional domains(eight in total).sphingolipid activator protei ns A(SAP-A)andSAP-B.Protein in teraction found that it may interact with proteins such as CTSH,CSF2RA and NAPSA.CONCLUSIONS SFTPB protein is an unstable lipophilic protein mainly composed ofα-helix.which is secreted by alveolar cells and acts mainly outside the cell.It can stabilize the surface tension of alveoli and plays a crucial role in preventing lung injury,which may contribute to the diagnosis and treatment of lung cancer.
作者
管鑫
何梦荣
汪速飞
许娟娟
GUAN Xin;HE Meng-rong;WANG Su-fei;XU Juan-juan(Tongji Medical College ,Huazhong University of Science and Technology ,Wuhan 430030,P.R.China;Department of Respiratory and Critical care Medicine,Affiliated Uuion Hospital of Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430030,P.R.China)
出处
《中华肿瘤防治杂志》
CAS
北大核心
2019年第4期226-232,共7页
Chinese Journal of Cancer Prevention and Treatment
基金
国家青年科学基金(81800094)
华中科技大学技术创新基金(2018JYCXJJ017)
华中科技大学研究生创新创业基金(5003530053)
