人心脏肌钙蛋白I标准品的异质性。

Heterogeneity in human cardiac troponin I standards.

作者信息

Bunk D M, Dalluge J J, Welch M J

机构信息

Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8392, Gaithersburg, Maryland 20899, USA.

出版信息

Anal Biochem. 2000 Sep 10;284(2):191-200. doi: 10.1006/abio.2000.4710.

DOI:10.1006/abio.2000.4710

PMID:10964401

Abstract

The LC-MS analysis of recombinant cardiac troponin I (cTnI) and cTnI extracted from human hearts showed a high degree of structural heterogeneity among all samples. The examined recombinant cTnI samples indicated posttranslational modifications, presumably due to their purification (i.e., 2-mercaptoethanol adducts and carbamylation) and related to their expression (i.e., an N-terminal expression tag). The extracted cTnI samples, while having a higher degree of structural heterogeneity, showed less structural variance between samples than the recombinant proteins. The LC-MS analysis of the extracted cTnI samples provided evidence of posttranslational modification by phosphorylation, acetylation, proteolytic cleavage, and intrachain disulfide bond formation.

摘要

对重组心肌肌钙蛋白I（cTnI）和从人心脏中提取的cTnI进行的液相色谱-质谱（LC-MS）分析表明，所有样品之间存在高度的结构异质性。所检测的重组cTnI样品显示出翻译后修饰，推测这是由于其纯化过程（即2-巯基乙醇加合物和氨甲酰化）以及与表达相关（即N端表达标签）。提取的cTnI样品虽然结构异质性程度较高，但样品之间的结构差异比重组蛋白小。对提取的cTnI样品进行的LC-MS分析提供了磷酸化、乙酰化、蛋白水解切割和链内二硫键形成等翻译后修饰的证据。