Medina Martha L, Haynes Paul A, Breci Linda, Francisco Wilson A
Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA.
Proteomics. 2005 Aug;5(12):3153-61. doi: 10.1002/pmic.200401136.
MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data. This peptide identification data can then be grouped and reconstructed into protein data. In this study, we have used this approach to study protein secretion by Aspergillus flavus, a filamentous fungus for which very little genome sequence information is available. A. flavus is capable of degrading the flavonoid rutin (quercetin 3-O-glycoside), as the only source of carbon via an extracellular enzyme system. In this continuing study, a proteomic analysis was used to identify secreted proteins from A. flavus when grown on rutin. The growth media glucose and potato dextrose were used to identify differentially expressed secreted proteins. The secreted proteins were analyzed by 1- and 2-DE and MS/MS. A total of 51 unique A. flavus secreted proteins were identified from the three growth conditions. Ten proteins were unique to rutin-, five to glucose- and one to potato dextrose-grown A. flavus. Sixteen secreted proteins were common to all three media. Fourteen identifications were of hypothetical proteins or proteins of unknown functions. To our knowledge, this is the first extensive proteomic study conducted to identify the secreted proteins from a filamentous fungus.
蛋白质组学中的串联质谱技术使得从几乎没有或完全没有基因组序列信息的生物体中鉴定蛋白质成为可能。通过将肽质量和片段化信息与来自相关生物体（包括未注释的基因组序列数据）的蛋白质序列信息进行匹配，从串联质谱中获得肽序列。然后可以将这些肽鉴定数据进行分组并重建为蛋白质数据。在本研究中，我们采用这种方法来研究黄曲霉（一种几乎没有基因组序列信息的丝状真菌）的蛋白质分泌情况。黄曲霉能够通过细胞外酶系统将黄酮类芦丁（槲皮素3 - O - 糖苷）作为唯一碳源进行降解。在这项持续研究中，利用蛋白质组学分析来鉴定在芦丁上生长的黄曲霉分泌的蛋白质。使用生长培养基葡萄糖和马铃薯葡萄糖来鉴定差异表达的分泌蛋白。通过一维电泳和二维电泳以及串联质谱对分泌蛋白进行分析。从这三种生长条件下共鉴定出51种独特的黄曲霉分泌蛋白。其中10种蛋白质是芦丁生长的黄曲霉所特有的，5种是葡萄糖生长的黄曲霉所特有的，1种是马铃薯葡萄糖生长的黄曲霉所特有的。16种分泌蛋白在所有三种培养基中都存在。14种鉴定结果是假设蛋白或功能未知的蛋白。据我们所知，这是首次进行的广泛蛋白质组学研究，旨在鉴定丝状真菌分泌的蛋白质。
