Effective top-down LC/MS+ method for assessing actin isoforms as a potential cardiac disease marker. Anal Chem 2015 Aug 18;87(16):8399-8406
Date
07/21/2015Pubmed ID
26189812Pubmed Central ID
PMC4965275DOI
10.1021/acs.analchem.5b01745Scopus ID
2-s2.0-84939839664 (requires institutional sign-in at Scopus site) 20 CitationsAbstract
Actin is the major component of the cytoskeleton, playing an essential role in the structure and motility of both muscle and nonmuscle cells. It is highly conserved and encoded by a multigene family. α-Cardiac actin (αCAA) and α-skeletal actin (αSKA), encoded by two different genes, are the primary actin isoforms expressed in striated muscles. The relative expression levels of αSKA and αCAA have been shown to vary between species and under pathological conditions. In particular, an increased αSKA expression is believed to be a programmed response of a diseased heart. Therefore, it is essential to quantify the relative expression of αSKA and αCAA, which remains challenging due to the high degree of sequence similarity between these isoforms (98.9%). Herein, we developed a top-down liquid chromatography/mass spectrometry-based ("LC/MS+") method for the rapid purification and comprehensive analysis of α-actin extracted from muscle tissues. We thoroughly investigated all of the actin isoforms in healthy human cardiac and skeletal muscles. We found that αSKA is the only isoform expressed in skeletal muscle, whereas αCAA and αSKA are coexpressed in cardiac muscle. We then applied our method to quantify the α-actin isoforms in human healthy hearts and failing hearts with dilated cardiomyopathy (DCM). We found that αSKA is augmented in DCM compared with healthy controls, 43.1 ± 0.9% versus 23.7 ± 1.7%, respectively. As demonstrated, top-down LC/MS+ provides an effective and comprehensive method for the purification, quantification, and characterization of α-actin isoforms, enabling assessment of their clinical potential as cardiac disease markers.
Author List
Chen YC, Ayaz-Guner S, Peng Y, Lane NM, Locher M, Kohmoto T, Larsson L, Moss RL, Ge YAuthor
Takushi Kohmoto MD, PhD Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ActinsBiomarkers
Chromatography, Liquid
Heart Diseases
Humans
Mass Spectrometry
Myocardium
Protein Isoforms
Reference Standards
Time Factors
