MALDI-TOF/TOF和LC-MS/MS液质联用分析大鼠脑脉络丛的多肽组

脉络丛(choroid plexus,CP)位于血液与脑脊液(cerebrospinal fluid,CSF)之间,不仅是CSF的重要来源,而且是构成血液-脑脊液屏障(blood-cerebrospinal fluid barrier,BCB)的组织基础.CP参与脑组织中一些血源性多肽的输送以及自身多肽合成的生理过程,在维持脑微环境动态平衡和调节中枢神经系统的正常功能方面起到非常重要的作用.本研究分别运用MALDI-TOF/TOF和LC-MS/MS液质联用系统分析了成年SD大鼠血液-脑脊液屏障(即脉络丛组织)中的多肽组.共鉴定到163个多肽(P0.001),这些多肽为69种蛋白质的降解肽段,其中ATP合酶(ATP synthase),细胞色素c(cytochrome c),血红蛋白(hemoglobin),NADH-辅酶Q氧化还原酶(NADH-ubiquinone oxidoreductase),β珠蛋白(beta-globin)这5种蛋白质的肽段数占总肽段数的50%以上,并且部分多肽序列相似度高,类似其前体蛋白的逐步降解片段,而这些前体蛋白质的分子量多数在10kD至20kD之间.上述研究结果为SD大鼠脉络丛组织的生理功能研究及组织多肽组学的研究方法提供了有价值的科学资料.

Peptidome in Rat Choroid Plexus by MALDI-TOF/TOF and LC-MS/MS Analysis

Choroid plexus (CP) is the major source of cerebrospinal fluid (CSF), as well as a major part of the blood-CSF barrier (BCB) to insulate the systemic circulation and the CSF. Yet CP also is actively involved the material transportation in between, including blood-derived peptides and autogenous peptides, to maintain the homeostasis of CNS microenvironment. In this study, we identified a total of 163 peptides from the CP samples of adult Sprague-Dawley (SD) rat by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry（MALDI-TOF/TOF）and nano-liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Sixty-nine of the identified peptides were derived from five precursors, including ATP-synthase, cytochrome c, hemoglobin, NADH-ubiquinone oxidoreductase, beta-globin, in the forms of degrading fragments with the molecular weights of 10~20 kD. These peptides showed a ladder-fashioned degradation pattern and were sharing high similarities. This study provided pilot characterization of the major peptides in the CP and might be useful for further studies for physiological functions.