Proteomic analysis of the temporal expression of bovine milk proteins during coliform mastitis and label-free relative quantification

The discovery of biomarkers in milk indicative of local inflammation or disease in the bovine mammary gland has been hindered by the extreme biological complexity of milk, the dynamic range of proteins in the matrix that renders the identification of low-abundance proteins difficult, and the challenges associated with quantifying changes during disease in the abundance of proteins for which no antibody exists. The objectives of the current study were to characterize the temporal expression of milk proteins following Escherichia coli challenge and to evaluate change in relative abundance of identified proteins using a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) label-free semiquantitative approach. Liquid chromatography-MS/MS conducted on whey from milk samples collected just before infusion with E. coli and at 12, 18, 24, 36, 48, and 60 h following infection resulted in the identification of the high- to medium-abundance proteins α_S1-, α_S2- β-, and κ-caseins and the whey proteins serum albumin, β-lactoglobulin, and α-lactalbumin. Additionally, a select number of lower abundance markers of inflammation were also identified, including lactoferrin, transferrin, apolipoprotein AI, fibrinogen, glycosylation-dependent cell adhesion molecule-1, peptidoglycan recognition receptor protein, and cyclic dodecapeptide-1. Normalized peptide counts for each protein identified were used to evaluate temporal changes in milk proteins following infection. For comparison with relative protein abundance determined using proteomic-based methods, changes in serum albumin, lactoferrin, and transferrin in milk during disease were also measured using ELISA. Label-free, proteomic-based quantification revealed relative changes in milk proteins that corresponded to expression profiles generated by ELISA. The results indicate that label-free LC-MS/MS methods are a viable means of tracking changes in relative protein abundance in milk during disease. Despite the identification of primarily abundant milk proteins, the results indicate that, with further refinement, LC-MS/MS could be used to evaluate temporal changes in proteins related to host response for which no antibody or ELISA currently exists.     

The integration of proteomics and systems approaches to map regulatory mechanisms underpinning platelet function

Platelets in the circulation are triggered by vascular damage to activate, aggregate and form a thrombus that prevents excessive blood loss. Platelet activation is stringently regulated by intracellular signalling cascades, which when activated inappropriately lead to myocardial infarction and stroke. Strategies to address platelet dysfunction have included proteomics approaches which have lead to the discovery of a number of novel regulatory proteins of potential therapeutic value. Global analysis of platelet proteomes may enhance the outcome of these studies by arranging this information in a contextual manner that recapitulates established signalling complexes and predicts novel regulatory processes. Platelet signalling networks have already begun to be exploited with interrogation of protein datasets using in silico methodologies that locate functionally feasible protein clusters for subsequent biochemical validation. Characterization of these biological systems through analysis of spatial and temporal organization of component proteins is developing alongside advances in the proteomics field. This focused review highlights advances in platelet proteomics data mining approaches that complement the emerging systems biology field. We have also highlighted nucleated cell types as key examples that can inform platelet research. Therapeutic translation of these modern approaches to understanding platelet regulatory mechanisms will enable the development of novel anti-thrombotic strategies.     

Toward a Successful Clinical Neuroproteomics The 11th HUPO Brain Proteome Project Workshop 3 March, 2009, Kolymbari, Greece

The HUPO Brain Proteome Project (HUPO BPP) held its 11th workshop in Kolymbari on March 3, 2009. The principal aim of this project is to obtain a better understanding of neurodiseases and ageing, with the ultimate objective of discovering prognostic and diagnostic biomarkers, in addition to the development of novel diagnostic techniques and new medications. The attendees came together to discuss sub-project progress in the clinical neuroproteomics of human or mouse models of Alzheimer's and Parkinson's disease, and to define the needs and guidelines required for more advanced proteomics approaches. With the election of new steering committees, the members of the HUPO BPP elaborated an actual plan promoting activities, outcomes, and future directions of the HUPO BPP to acquire new funding and new participants.     

数据库加密技术研究

信息安全的核心就是数据库的安全,也就是说数据库加密是信息安全的核心问题。数据库数据的安全问题越来越受到重视,数据库加密技术的应用极大地解决了数据库中数据的安全问题。本文主要就数据库加密技术方法和实现进行简要地概述。     

Proteomic study on protective mechanism of ischemic preconditioning to ischemia-reperfusion lung injury

Objective To investigate the change of protein expression of lung tissue of rabbit after ischemic preconditioning (IP) and try to elucidate the potential protective mechanism of IP. Methods 12 domestic rabbits were randomly divided into group IP and group control(6 rabbits in each group). All the left lungs were afflicted by ische mia-reperfusion injury except that those in group IP were subject to IP prior to ischemic phase. 2-DE was employed to separate the total protein of the lung tissue. PDQuest analysis software was used to distinguish the differently expressed protein spot. MALDI-TOF-MS and Mascot database searching were exploited to identify these proteins. Results 1) IP attenuated the ischemia-reperfusion lung injury. 2) The proteomic analysis showed 35 target proteins,of which 17 were characterized such as phosphatidylinositol 3-kinase(PI3k) delta catalytic subunit. Conclusions 1)Proteomic is a promising tool to investigate the IP and ischemia-reperfusion lung injury. 2) That IP inhibits inflammatory cascades through phosphatidylinositol 3-kinase signal transduction pathway may be one of its protective mechanism.     

Sequence requirements for Nalpha-terminal acetylation of yeast proteins by NatA

NatA is the major N-terminal acetyltransferase of the yeast Saccharomyces cerevisiae. In this study, we took advantage of our recent data on N-terminal acetylation of proteins of the yeast protein map to update the list of proteins with known NatA-dependent acetylation status. Furthermore, using the information available on the acetylation status of 100 novel proteins, we re-examined the rules for acetylation by NatA. The results refine our previous knowledge on NatA substrate specificity depending on the N-terminal and penultimate residues. In particular, we found that the acetylation frequencies of Ser-, Thr- and Ala-, the three residues most often acetylated by NatA, are higher than previously reported. In addition, comparison of the N-terminal region of acetylated and non-acetylated proteins revealed differences in amino acid composition that extend over the 25 first amino acid residues: acetylated proteins are characterized by a higher frequency of glutamate and glutamine and a lower frequency of lysine, arginine and histidine. We suggest that the particularities in amino acid composition of the N-terminal region of acetylated proteins facilitate its interaction with the Nat1p subunit of NatA and its guidance to the catalytic subunit Ard1p.