A proteomic analysis of aortic proteins in zinc and metallothionein deficiency

The objective of this work was to identify proteins and protein interactions that are modified by zinc and metallothionein (MT) deficiency in rodent aorta, using 2D gel proteomics. In one set of studies, 3-week old male rats were given either acutely (<1 mg Zn/kg) or marginally (6 mg Zn/kg) zinc deficient semi-synthetic diets for 5–6 weeks. Controls rats consumed a zinc-adequate diet (35 mg Zn/kg) and animals pair-fed with acutely deficient rats also consumed the adequate diet. Protein expression profiles in aorta were determined using 2D gel proteomics.In a second set of studies, aortic protein expression in adult male mice with a targeted disruption of the MT-1 and MT-2 genes and appropriate controls (both genotypes on a 129Sv genetic background) was studied using 2D gel proteomics.
In the rat studies, both marginal and acute zinc deficiency decreased the level of aortic proteins associated with carbohydrate metabolism and lipid biosynthesis. Acute zinc deficiency also suppressed proteins related to the cytoskeleton. Although MT deficiency also decreased cytoskeleton-related protein levels, it increased levels of some enzymes relating to carbohydrate/energy metabolism. Principal Component Analysis followed by correlation analysis revealed key proteins affected by MT deficiency. These included small GTP-binding and related proteins.