Table of Contents
International Journal of Proteomics
Volume 2012, Article ID 397103, 8 pages
Research Article

Plasma Fractionation Enriches Post-Myocardial Infarction Samples Prior to Proteomics Analysis

1San Antonio Cardiovascular Proteomics Center, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78245, USA
2Division of Geriatrics, Gerontology & Palliative Medicine, Department of Medicine, UTHSCSA, San Antonio, TX 78245, USA
3Department of Biochemistry, UTHSCSA, San Antonio, TX 78245, USA

Received 15 March 2012; Accepted 9 April 2012

Academic Editor: William C. S. Cho

Copyright © 2012 Lisandra E. de Castro Brás et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Following myocardial infarction (MI), matrix metalloproteinase-9 (MMP-9) levels increase, and MMP-9 deletion improves post-MI remodeling of the left ventricle (LV). We provide here a technical report on plasma-analysis from wild type (WT) and MMP-9 null mice using fractionation and mass-spectrometry-based proteomics. MI was induced by coronary artery ligation in male WT and MMP-9 null mice (4–8 months old; /genotype). Plasma was collected on days 0 (pre-) and 1 post-MI. Plasma proteins were fractionated and proteins in the lowest (fraction 1) and highest (fraction 12) molecular weight fractions were separated by 1-D SDS-PAGE, digested in-gel with trypsin and analyzed by HPLC-ESI-MS/MS on an Orbitrap Velos. We tried five different fractionation protocols, before reaching an optimized protocol that allowed us to identify over 100 proteins. Serum amyloid A substantially increased post-MI in both genotypes, while alpha-2 macroglobulin increased only in the null samples. In fraction 12, extracellular matrix proteins were observed only post-MI. Interestingly, fibronectin-1, a substrate of MMP-9, was identified at both day 0 and day 1 post-MI in the MMP-9 null mice but was only identified post-MI in the WT mice. In conclusion, plasma fractionation offers an improved depletion-free method to evaluate plasma changes following MI.