This case study is to report the proteins detected by proteomic analysis of synovial fluid from a dog diagnosed with idiopathic immune-mediated polyarthritis, and to compare it with healthy dogs. Synovial fluid was collected via arthrocentesis from a dog diagnosed with immune-mediated polyarthritis. Protein precipitation was performed on the synovial fluid, followed by isoelectric focusing and 2-dimensional gel electrophoresis. The spots on the 2-dimensional gels were analyzed using MALDI-TOF/MS. The results were then analyzed against the MASCOT database. The results from the proteomic analysis revealed an abundance of several types of immunoglobulins together with the presence of complement C4b-binding protein alpha chain. Actin and keratin were also among the proteins detected. Proteomic studies, facilitate a better understanding of the different levels of proteins expressed during disease activity. Potential disease biomarkers can aid in the diagnosis of disease, as well as help in monitoring treatment efficacy and providing prognosis for the patient.
A new proteomics technology has been implemented to study the protein repertoires of developing oocytes of giant grouper (Epinephelus lanceolatus). Knowledge of the chemical composition and physiochemical properties of vitellogenin (Vtg) is necessary to interpret the functional and biological properties attributed during ovulation. Vtg, as a biomarker indicator in sex determination, has been analyzed to determine the sex and maturational status of fish in the absence of the gonad tissue. A male giant grouper was induced by 2 mg/kg of 17ß-estradiol (E2), and blood was sampled at days 0, 1, 3, 5, and 10. SDS-PAGE 1D electrophoresis was used to analyze Vtg protein, and Vtg identification was done with 4800 Plus MALDI TOF/TOF™ mass spectrophotometer (Applied Biosystems/MDS SCIEX, USA). Meanwhile, MS/MS de novo sequencing identified the proteins by matching sequences of tryptic peptides to the known sequences of other species. Vtg was confirmed by MASCOT at 95% significant level, and molecular mass was 187 kDa. Protein resolved on SDS-PAGE as a double band of approximately the same mass as determined with MALDI-TOF. The N-terminal sequences and identification of Vtg were also determined. The potential of using MS methods to understand the structure and function of Vtg is discussed.