The application of proteomics is relevant to physiology, reproduction, immunology, muscle and lactational biology in animal science, altough its use is still limited. One of the greatest challenges of proteome analysis is the reproducible fractionation of the complex protein mixtures. The fractionation methods can increase the probability of bi...omarker protein discovery. The fractionation by liquid-phase isoelectric focusing is one of the prefractionation methods. As a result, protein fractions can be easily collected, pooled and refractionated. There is a lack in the knowledge of gel-based proteomic methods of egg as only a limited number of protocols can be found in the literature, thus sample purification and fractionation require a time consuming optimisation procedure. The aim of this study was to fractionate egg yolk and white proteins by isoelectric point in liquid phase.
The aim of the present study was to determine marker proteins those are associated with functional longevity of dairy cattle. Holstein-Friesian cows were grouped based on their performance as follows: group 1) individuals with good longevity traits; group 2) short production life because of poor reproduction traits; group 3) short production li...fe with low milk yield. Twelve individuals were sampled in each group, blood and milk samples were collected from cows. Blood samples were analysed with two dimensional polyacrylamide gel electrophoresis (2D PAGE), MALDI TOF/TOF and nanoLCMS/MS. The milk samples were analysed with MALDI TOF/TOF and nanoLC-MS/MS. Using the optimized gel based proteomic approach,
we have succesfully separated 143 proteins in the group1, 139 proteins in the group2 and 136 proteins in the group3, but we could not find significant differences between groups in the expression pattern. Using MALDI TOF/TOF and nanoLC-IonTrap MS, we have found eleven protein sequences those were expressed only in the samples of good longevity group.
The aims of the present study were to optimize a two dimensional polyacrylamide gel electrophoresis method to chicken liver proteome and to determine the changes of protein expression caused by selenium. Twelve broiler chicken were used in this experiment. The selenium intake was 0,2 mg/kg in the control group (6 chicken) and 4,25 mg/kg in the...experimental group (6 chicken). Using the optimized proteomic approach, we have succesfully separated 747 proteins in the experimental group and 741 proteins in the control group. We found six proteins, wich expressed only in the samples of experimental group. Further investigations need to determine these six proteins with mass spectrometry (MS) and look for the correlation between the physiological effects of selenium and the expression of these proteins.