Guo Tong, Rudnick Paul A, Wang Weijie, Lee Cheng S, Devoe Don L, Balgley Brian M
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.
J Proteome Res. 2006 Jun;5(6):1469-78. doi: 10.1021/pr060065m.
Saliva is a readily available body fluid with great diagnostic potential. The foundation for saliva-based diagnostics, however, is the development of a complete catalog of secreted and "leaked" proteins detectable in saliva. By employing a capillary isoelectric focusing-based multidimensional separation platform coupled with electrospray ionization tandem mass spectrometry (MS), a total of 5338 distinct peptides were sequenced, leading to the identification of 1381 distinct proteins. A search of bacterial protein sequences also identified many peptides unique to several organisms and unique to the NCBI nonredundant database. To the best of our knowledge, this proteome study represents the largest catalog of proteins measured from a single saliva sample to date. Data analysis was performed on individual MS/MS spectra using the highly specific peptide identification algorithm, OMSSA. Searches were conducted against a decoyed SwissProt human database to control the false-positive rate at 1%. Furthermore, the well-curated SwissProt sequences represent perhaps the least redundant human protein sequence database (12,484 records versus the 50,009 records found in the International Protein Index human database), therefore minimizing multiple protein inferences from single peptides. This combined bioanalytical and bioinformatic approach has established a solid foundation for building up the human salivary proteome for the realization of the diagnostic potential of saliva.
唾液是一种易于获取的体液，具有巨大的诊断潜力。然而，基于唾液的诊断方法的基础是开发出一份完整的、可在唾液中检测到的分泌蛋白和“渗漏”蛋白目录。通过采用基于毛细管等电聚焦的多维分离平台并结合电喷雾电离串联质谱（MS），总共对5338个不同的肽段进行了测序，从而鉴定出1381种不同的蛋白质。对细菌蛋白序列的搜索还发现了许多几种生物体所特有的以及NCBI非冗余数据库所特有的肽段。据我们所知，这项蛋白质组研究代表了迄今为止从单个唾液样本中测得的最大的蛋白质目录。使用高度特异性的肽段鉴定算法OMSSA对单个MS/MS谱进行数据分析。针对经过诱饵处理的SwissProt人类数据库进行搜索，以将假阳性率控制在1%。此外，精心整理的SwissProt序列可能是冗余度最低的人类蛋白质序列数据库（12484条记录，而国际蛋白质索引人类数据库中有50009条记录），因此可最大程度减少单个肽段产生的多种蛋白质推断。这种生物分析和生物信息学相结合的方法为构建人类唾液蛋白质组奠定了坚实基础，以实现唾液的诊断潜力。
