纳升电喷雾串联质谱鉴定重组人甲状旁腺素(1-34)

Identification of Recombinant Human Parathyroid Hormone (1-34) by Nanoelectrospray Ionization-Quadrupole-Time of Filght Tandem Mass Spectrometry

用先进的纳升电喷雾-四极杆-飞行时间串联质谱鉴定重组人PTH(1-34)。通过ESI-MS测定重组人PTH(1-34)分子量及MS/MS对其胰蛋白酶酶解后的肽段的序列和数据库查询进行结构鉴定。重组PTH(1-34)测定分子量为4115.21,与理论值相比测定相差0.06%。MS/MS测定出其中双电荷离子峰m/z728.4肽段序列为VSEIQLMHNLG,以及其他3个单电荷离子峰的序列。数据库检索后确定重组表达的PTH(1-34)一级结构完全正确,纳升电喷雾串联质谱以其灵敏、快速和准确为蛋白质鉴定提供了有效的手段。

Recombinant human parathyroid hormone （PTH） （1-34） was identified by new technique nanoelectrospray ionization （ESI）-quadrupole-time of flight （TOF） tandem mass spectrometry. The measured molecular weight of PTH （ 1-34 ） was 4115.21 by ESI-mass spectrometry （MS） and measurement percent error was only 0.06 %. Digested PTH（1-34） by trypsin at 37℃ over night. The tryptic digested peptides were measured and then four charged peptides were selected to determine amino acid sequence by MS/MS. Then their sequences were interpreted from a, b, y series ions of peptides by the collision-induced-dissociation （CID） in the product ion mode. The sequence of peptide m/z 728.4 measured by MS/MS was VSEIQLMHNLGK. And all peptides sequences and database search results were both PTH （1-34）. The study proves that the primary structure of recombinant PTH （1-34） is correct . There is no amino acid deleted, mutated and modified in its expression and purification. It also shows that nanoESI-MS/MS is a good method to identify protein and acquire integrated sequence information with advantage of sensitivity, high speed and accuracy.