We provide genetic and biochemical data strongly suggesting that cysteines C(547) and C(549) from the C(547) DC(549) RGDC(553) FC(555) motif inserted in the HI loop of the Ad5 fiber form a single disulfide bond, with this disulfide bond being crucial for Ad5RGD4C retargeting to av-integrins.

Differentially expressed proteins identified exclusively by peptide sequence reading provided promising results for CAF-/CAF+ implementation in a standard proteomics workflow (e.g., biomarker and mutation discovery and biotyping). The practical performance of a reliable de novo sequencing technique in routine proteomics analysis is emphasized in this article.

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Amino acid sequencing and more detailed structure elucidation analysis of peptides and small proteins is a very difficult task even if state-of-the-art mass spectrometry (MS) is employed. To make this task easier, chemical derivatization methods of the N terminus with 4-sulfophenyl-isothiocyanate (SPITC) or the C terminus with 2-methoxy-4,5-dihydro-1H-imidazole (Lys-tag) can enhance peptide fragmentation or fragment ionizability, via proton mobility/localization mechanisms making tandem MS (MS(2)) spectra more informative and less demanding for structural interpretation. Observed disadvantages related to both derivatization methods are sample- and time-consuming procedures and the increased number of reaction byproducts. A novel, sulfate radical in-source formation method of matrix-assisted laser desorption ionization (MALDI) MS based on chemically enhanced in-source decay (ISD) can be accomplished by simple addition of ammonium persulfate (APS) in the matrix solution. This method enables effective decomposition of peptide ions already in the first stage of MS analysis where a large number of fragment ions are produced. The resultant MALDI-ISD mass spectra (MS after APS → MALDI-ISD MS) are almost equivalent to conventional, collision-induced dissociation (CID) MS(2) spectra. These fragment ions are further subjected to the second stage of the MS, and consequently, MS(3) spectra are produced, which makes the sequence analysis more informative and complete (CID MS(2) is thus equivalent to CID MS(3)). Multiply stage MS after APS addition showed enhanced sensitivity, resolution, and mass accuracy compared to peptide derivatization (SPITC and Lys-tag) or conventional MS and MS(2) analyses and offered more detailed insight into peptide structure.

Research background. Baranjski kulen is one of the most popular fermented meat sausages originating from Croatia. It has protected geographical indication, and is traditionally produced in the Baranja region of Croatia. Kulenova seka is a fermented sausage very similar to Baranjski kulen, but it has a different caliber and consequently, a shorter time of production. In recent decades, due to the high demand and popularity of these products, industrially produced Baranjski kulen and Kulenova seka have become available on the market. This work aims to identify specific characteristics of traditional and industrial sausages, Baranjski kulen and Kulenova seka on proteome, peptidome and metabolome level which could potentially lead to better optimization of the industrial production process in order to obtain an equivalent to the traditional product. Experimental approach. Protein profiles of Baranjski kulen and Kulenova seka (traditional and industrial) were analysed using two-dimensional gel electrophoresis followed by differential display analysis and protein identification using mass spectrometry. Peptidomics profiling analysis was performed via liquid chromatography-tandem mass spectrometry. Furthermore, aroma profiles were investigated via headspace solid phase microextraction and gas chromatography-mass spectrometry. Results and conclusions. The major identified characteristics of each product were: industrial Baranjski kulen - specific degradation of MYH1 and TITIN, overabundance of stress-related proteins and increased phenylalanine degradation; traditional Baranjski kulen - decreased concentration of phenylalanine and overabundance of ALDOA and CAH3; industrial Kulenova seka - specific MYH4 and HBA degradation process; traditional Kulenova seka - overabundance of DPYD and MYL1, degradation of ALBU and MYG, decreased concentrations of almost all free amino acids and increased amounts of smoke derived volatile compounds. Novelty and scientific contribution. In this preliminary communication, the first insights into protein degradation processes and generation of peptides, free amino acids and aroma compounds of industrial and traditional Baranjski kulen and Kulenova seka are presented. Although further research is needed to draw general conclusions, the specific profile of proteins, peptides, amino acids, and volatile compounds represents the first step in the industrial production of sausages that meet the characteristics of traditional flavour.