Proteomics is a powerful subject focusing on large-scale study of protein structures and functions. A complete enzymatic digestion of protein complexes is the key step in modern high-resolution and high-throughput mass spectrometry (MS)-based identification and quantification. To achieve MS analysis, both peptide sample pretreatment and data acquisition are prerequisite in proteomic studies. In this paper, we summarized both the enzymatic proprieties of three common proteolytic enzymes, Trypsin, Lys-C and Glu-C, the optimization of multi-enzyme combination and an advanced sample pretreatment in proteomics research.
Enzymes ; chemistry ; Mass Spectrometry ; Proteins ; chemistry ; Proteomics ; methods ; Trypsin ; chemistry

The stable isotope labeling by amino acids in culture (SILAC) based quantitative proteomics serves as a gold standard because of the high accuracy and throughput for protein identifications and quantification. In this study, we discussed the application of SILAC technology in mammal model, and developed quantitative internal standard for comparative proteomics of disease model. The C57BL/6J mice fed by special diet containing the 13C6-Lysine and bred F2 generation. We identified and analyzed total proteins of 9 mice tissues of F2 generation, including brain, lung, heart, stomach, intestine, liver, spleen, kidney, and muscle. Quantitative analysis information could evaluate the mice and different tissues' labeling efficiency. Liver was the most efficient, brain the least, and the labeling efficiency were 96.34%±0.90% and 92.62%±1.98% respectively. The average of the labeling efficiency of F2 generation was 95.80%±0.64%, which met the international standard (≥ 95%) for SILAC quantitative proteomics effective study. SILAC technology was successfully extended to mammalian model system, which will provide powerful tools for the mechanism study of the pathophysiology process with mouse model.
Amino Acids ; chemistry ; Animals ; Diet ; veterinary ; Isotope Labeling ; Lysine ; chemistry ; Mice ; Mice, Inbred C57BL ; Proteins ; chemistry ; Proteomics ; methods

Objective To analyze the epidemiological characteristics of severe fever cases,with thrombocytopenia syndrome (SFTS) in Zhoushan,Zhejiang,2011-2013 and to provide evidence for the development of related strategies for prevention and control of the disease.Methods Data was collected from the studies and related demography of the cases with SFTS in Zhoushan,2011-2013.Clinical and epidemiological characteristics of the cases with SFTS were analyzed descriptively.Results During 2011-2013,45 SFTS cases were reported in Zhoushan city,with fatality rate as 11.11％ (5/45),including 41 cases (91.11％) reported in Daishan county.Most cases aged 50 or over,residing in hilly regions (93.33％).The epidemic peak was seen from May to July (84.44％).Incidence rates of the disease did not show significant statistical differences between males and females.Most cases were farmers (42.22％) and housewives (31.11％).Most patients complained of fever (97.78％),anorexia (91.11％),fatigue (62.22％),chill (44.44％) and other non-specific clinical manifestations but all appeared progressive thrombocytopenia and leucopenia.Sanitation condition of the patients was generally poor.68.89％ (31/45) of cases had farmed,mowed or involved in other outdoor activities in the previous two weeks,with some of them reported having exposed to tick bites.Three events were reported,epidemiologically.Conclusion SFTS in Zhoushan was a infectious disease with natural foci and caused by SFTSV.Ticks might serve as the main vectors for SFTSV,and might cause direct transmission between humans.Improving the environment for living and carrying out essential protective measures in outdoor activities seemed to be significant in decreasing the incidence rate of the disease.