An metalloproteomics and expression approach of the structural, proteolytic and tissue skeletal muscle regulatory proteins in post-mortem and the relationship with growth and meat tenderness in Nellore animals (Bos indicus).
This project aims to conduct a more specifies approach on the characterization, expression and quantification of important proteins related with the growth of the skeletal muscle tissue and meat tenderness in of Nellore animals. For that will be used data and samples from 90 male animals Nellore whole aged approximately 27 months undergoing growth management and finishing in feedlot for 95 days. During the feedlot were taken measurements of weight and calculated the live weight gains in the periods. The animals were slaughtered at average live weight of 550 kg, when then were colleted samples for analysis of gene and protein expression. The carcasses were then cooled for 24 hours when they were collected samples of the Longissimus thoracis muscle to realization of the analyzes of production and of meat quality as: rib eye area, backfat thickness, instrumental color of the meat, shear force, cooking losses and determination of myofibrillar fragmentation index and intramuscular lipid content of the meat. The animal performance characteristic, carcass and meat quality will be related to the analytical studies of proteins. For this will be adopted specific bioanalytical methods as the separation of proteins by two-dimensional electrophoresis (2D-PAGE) with emphasis in the HSP family proteins and the calpain complex (calpain-I, calpain-II and calpastatin). There will also be performed the identify the calcium ions in the protein spots by X-ray fluorescence (XRF-SR) and characterization of proteins by mass spectrometry (ESI-MS). The gene expression analysis will be made (RT-PCR) of the myofibrillar protein myosin heavy chain (MyHC) and related postmortem proteolysis in as calpain-I, calpain-II and calpastatin. Assays quantitation of proteins by Western blot will also be performed for isoforms MyHC (I, IIa, IIb and IIx) for the calpain complex. (AU)
Articles published in Agência FAPESP Newsletter about the research grant: