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The aim of study was to isolate, characterize and analyse the protein profiles of Myoviridae-like bacteriophages obtained from M. haemolytica using MALDI TOF mass spectrometry. The material consisted of the M. haemolytica reference strain ATCC ® BAA410, reference serotypes A1, A2, A5, A6, A7, A9, and A11, and wild-type isolates of serotype A1. Bacteriophage morphology was examined with a transmission electron microscope. The proteins were separated in SDS-PAGE and two-dimensional electrophoresis and characterized by MALDI-TOF. Among the phages obtained, seven were specific for strains A1, A2, A5, A6, A7 and 25, and PHL-1 was specific for the BAA410 strain. The protein profiles for the phages were very similar to one another, but differed from the reference phage in that they lacked protein fractions with molecular weights of 22.9, 56.3 and 73.1 kDa. 2D electrophoresis revealed significant differences in the size of proteins and their localization in the pH gradient. The most similar profiles were observed in phages specific for strains BAA-410 and A6. In all profiles two main spots were observed in the molecular weight range from 44 to 70 kDa at pH < 4. The results indicate that 2D electrophoresis is a very useful tool for characterization of phage protein profiles. An important objective was to determine the molecular differences between morphologically similar phages belonging to one family and to find similarities to phages specific for other pathogens. The study also assessed the suitability of the methods used to characterize phages.

Cochliobolus lunatus abundantly produces four-celled conidia at high temperatures (>30 °C) and under suitable conditions; the fungus colonizes potato (Solanum tuberosum L.) cultivars by adopting different invasion strategies at the microscopic level. Long-lasting defence during infection requires an upsurge in proteome changes particularly pathogenesis-related proteins chiefly under the control of nonexpresser of pathogenesis-related proteins. In order to gain molecular insights, we profiled the changes in proteome and potato nonexpresser of pathogenesis-related proteins (StNPR1) during the infection process. It is found that C. lunatus significantly (P < 0.05) suppressed the host functional proteome by 96 h after infection (hai), principally, affecting the expression of ribulose bisphosphate carboxylase enzyme, plastidic aldolase enzyme, alcohol dehydrogenase 2 and photosystem II protein prior to the formation of brown-to-black leaf spot disease. Strongest host response was observed at 24 hai hallmarked by 307 differentially expressed peptide spots concurring with the active phase of production of penetrating hyphae. Additionally, C. lunatus differentially down-regulated StNPR1 transcript by 8.19 fold by 24 hai. This study is the first to elucidate that C. lunatus transiently down-regulates the expression of StNPR1 at the onset of infection, and as a whole, infection negatively affects the expression of proteome components involved in photosynthesis, carbon fixation and light assimilation. This study contributes towards better understanding of the mechanism underlining the invasion strategies of C. lunatus.

Purpose: Proteins in the vitreous play an important role on the induction of proliferative vitreoretinopathy (PVR) after retinal detachment. The aim of this study was to investigate the variation of protein patterns in the vitreous of PVR eyes and examine whether differentially expressed protein levels were expressed in experimental PVR retina., Methods: Vitreous samples from PVR and macular hole patients were selected for proteomic analysis. The vitreous protein samples were separated by two-dimensional electrophoresis (2-DE). The differentially expressed protein spots in the two groups were excised and subjected to in-gel digestion and identification by electrospray ionization mass spectrometry (ESI-MS) analysis. Two differentially expressed proteins, zinc finger protein 670 (ZFP 670) and prostaglandin D2 synthase (PGD2S), were further validated by immunohistochemical staining and western blotting analysis in the retina of the experimental rabbit PVR model., Results: In proteome analysis of human vitreous samples, five proteins had increased expression in PVR, including zinc finger protein 670 (ZFP 670), prostaglandin D2 synthase (PGD2S), IgG (Immunoglobulin G) light chain, transthyretin precursor, and haptoglobin precursor. ZFP 670 and PGD2S levels were expressed significantly higher in the experimental PVR retinas than in the control group., Conclusions: Levels of ZFP 670 and PGD2S were elevated in the vitreous fluid of patients with PVR. In addition, there were higher expressions of ZFP 670 and PGD2S in the experimental PVR retina. This result will expand our knowledge of pathophysiologic characteristics of PVR, and might be helpful for further developing possible treatment on this disorder.