小批量制备质谱纯魟鱼肝铁蛋白(liver ferritin of Dasyatis akajei,DALF),以透射电子显微镜术(TEM)测定DALF、蛋白壳和铁核的分子尺寸。SDS-PAGE技术指出,DALF由H和L两种不同类型的亚基组成。采用肽质量指纹图谱(PMF)技术进一步佐证H和L亚基类型和同源性。氧化还原剂中性红、劳氏紫、甲基紫精和pH1.5酸度均无法削弱DALF的H-L和L-L亚基之间的相互作用强度、并解吸出L亚基离子,供MALDI-TOF质谱仪分析。通过增加激光强度和降低基质pH途径,可直接分析DALF的H和L亚基的分子量,指出DALF中H-L和L-L亚基之间的相互作用强度明显高于H-H亚基类型。
Liver ferritin of Dasyatis akajei ( DALF ) with mass purity was prepared in batch. Transmission electron microscopy(TEM) was used to determine the molecular sizes of DALF, protein shell, and iron core, respectively. Experimental results of SDS-PAGE method indicated that DALF consisted of two different subunit types, H and L subunits. Moreover, both types of H and L subunits and their homology were further proofed by peptide mass fingerprinting(PMF). The redox reagents such as natural read, thionine, and methyl violo- gen, and the acidity at pH 1.5 have no abilities for making the interaction intensity of both H-L and L-L subunits reduced to form the ions of L subunit for mass analysis with MALDI-TOF MS, respectively. However, using a combined approach of increasing laser intensity and decreasing the matrix pH synchronously, MALDI- TOF mass spectrometric method has the ability for analyzing molecular weights both H and L subunits in DALF, It indicated that the interaction intensity of H-L and L-L subunit types was higher than that of H-H subunit type in DALF.