Abstract：
Two protocols of protein extraction from Arthrospira platensis (spirulina) microalgae to study their proteome by mass spectrometry (MS) are here presented. The first is based on an aqueous buffer solution of Tris-HCl and the second on cold acetone. The identification of proteins was carried out by a bottom-up approach, which involves enzymatic digestion of extracted proteins followed by either matrix-assisted laser desorption ionization with time-of-flight (MALDI-TOF) MS or liquid chromatography (LC) coupled with electrospray ionization (ESI) and Fourier-transform tandem MS. While MALDI-TOF MS allowed for a fast peptide mass fingerprinting (PMF) check yet identifying less than 20 proteins in the extracted samples, the data-dependent acquisitions (DDA) mode of reversed-phase (RP) LC-ESI tandem FTMS/MS separations allowed us to recognize more than one hundred proteins by searching into dedicated spectral libraries. The application of MALDI-TOF MS analysis was found, however, of great support for preliminary investigations of cyanobacteria samples before proceeding with the RPLC-ESI-MS/MS DDA investigation, which definitively allows for a qualitative proteome analysis also of minor spirulina proteins in processed foodstuffs. Although the protein content in spirulina can be influenced by cultivation and environmental conditions, e.g., light intensity, climate, and water/air quality, here the qualitative chemical profiles of the examined samples were characterized by similar composition in high-quality proteins as phycocyanins and phycoerythrins.
摘要：
本文介绍了两种从螺旋藻（螺旋藻）微藻中提取蛋白质的方法，以通过质谱（MS）研究其蛋白质组。第一种基于Tris-HCl的水性缓冲溶液，第二种基于冷丙酮。蛋白质的鉴定是通过自下而上的方法进行的，其中包括酶消化提取的蛋白质，然后进行基质辅助激光解吸电离与飞行时间（MALDI-TOF）MS或液相色谱（LC）结合电喷雾电离（ESI）和傅立叶变换串联MS。虽然MALDI-TOFMS允许快速的肽质量指纹图谱（PMF）检查，但在提取的样品中识别不到20种蛋白质，反相（RP）LC-ESI串联FTMS/MS分离的数据依赖性采集（DDA）模式使我们能够通过搜索专用光谱库来识别一百多种蛋白质。MALDI-TOFMS分析的应用发现，然而,在进行RPLC-ESI-MS/MSDDA调查之前，大力支持蓝藻样品的初步调查，这最终可以对加工食品中的少量螺旋藻蛋白进行定性蛋白质组分析。尽管螺旋藻中的蛋白质含量会受到栽培和环境条件的影响，例如，光强度,气候,和水/空气质量，在这里，所检查样品的定性化学特征是在高质量蛋白质中与藻蓝蛋白和藻红蛋白相似的组成。
